common/formatting/token_partition_tree_test.cc

// Copyright 2017-2020 The Verible Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "common/formatting/token_partition_tree.h"

#include <iosfwd>
#include <iterator>
#include <string>
#include <vector>

#include "absl/strings/str_split.h"
#include "absl/strings/string_view.h"
#include "common/formatting/format_token.h"
#include "common/formatting/token_partition_tree_test_utils.h"
#include "common/formatting/unwrapped_line.h"
#include "common/formatting/unwrapped_line_test_utils.h"
#include "common/util/container_iterator_range.h"
#include "common/util/tree_operations.h"
#include "common/util/vector_tree.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

namespace verible {
namespace {

using ::testing::ElementsAre;

// Helper class that initializes an array of tokens to be partitioned
// into TokenPartitionTree.
class TokenPartitionTreeTestFixture : public ::testing::Test,
                                      public UnwrappedLineMemoryHandler {
 public:
  TokenPartitionTreeTestFixture()
      : sample_("one two three four five six"),
        tokens_(absl::StrSplit(sample_, ' ')) {
    for (const auto token : tokens_) {
      ftokens_.emplace_back(TokenInfo{1, token});
    }
    CreateTokenInfos(ftokens_);
  }

 protected:
  const std::string sample_;
  const std::vector<absl::string_view> tokens_;
  std::vector<TokenInfo> ftokens_;
};

class VerifyFullTreeFormatTokenRangesTest
    : public TokenPartitionTreeTestFixture {};

TEST_F(VerifyFullTreeFormatTokenRangesTest, ParentChildRangeBeginMismatch) {
  // Construct three partitions, sizes: 1, 3, 2
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  // one short of partition0's begin, and will fail invariant.
  UnwrappedLine all(0, begin + 1);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine partition0(0, begin);
  partition0.SpanUpToToken(begin + 1);
  UnwrappedLine partition1(0, partition0.TokensRange().end());
  partition1.SpanUpToToken(begin + 4);
  UnwrappedLine partition2(0, partition1.TokensRange().end());
  partition2.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{partition0},
      tree_type{partition1},
      tree_type{partition2},
  };

  EXPECT_DEATH(VerifyFullTreeFormatTokenRanges(tree, begin),
               "Check failed: parent_begin == children_begin");
}

TEST_F(VerifyFullTreeFormatTokenRangesTest, ParentChildRangeEndMismatch) {
  // Construct three partitions, sizes: 1, 3, 2
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  // one short of partition2's end, and will fail invariant.
  all.SpanUpToToken(preformat_tokens.end() - 1);
  UnwrappedLine partition0(0, begin);
  partition0.SpanUpToToken(begin + 1);
  UnwrappedLine partition1(0, partition0.TokensRange().end());
  partition1.SpanUpToToken(begin + 4);
  UnwrappedLine partition2(0, partition1.TokensRange().end());
  partition2.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{partition0},
      tree_type{partition1},
      tree_type{partition2},
  };

  EXPECT_DEATH(VerifyFullTreeFormatTokenRanges(tree, begin),
               "Check failed: parent_end == children_end");
}

TEST_F(VerifyFullTreeFormatTokenRangesTest, ChildrenRangeDiscontinuity) {
  // Construct three partitions, sizes: 1, 3, 2
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine partition0(0, begin);
  partition0.SpanUpToToken(begin + 1);
  UnwrappedLine partition1(0, partition0.TokensRange().end());
  partition1.SpanUpToToken(begin + 3);
  // There is a gap between partition1 and partition2 that fails an invariant.
  UnwrappedLine partition2(0, partition1.TokensRange().end() + 1);
  partition2.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{partition0},
      tree_type{partition1},
      tree_type{partition2},
  };

  EXPECT_DEATH(VerifyFullTreeFormatTokenRanges(tree, begin),
               "Check failed: current_begin == previous_end");
}

class FindLargestPartitionsTest : public TokenPartitionTreeTestFixture {};

// Verify that this finds the K largest leaf partitions.
TEST_F(FindLargestPartitionsTest, VectorTree) {
  // Construct three partitions, sizes: 1, 3, 2
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine partition0(0, begin);
  partition0.SpanUpToToken(begin + 1);
  UnwrappedLine partition1(0, partition0.TokensRange().end());
  partition1.SpanUpToToken(begin + 4);
  UnwrappedLine partition2(0, partition1.TokensRange().end());
  partition2.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{partition0},
      tree_type{partition1},
      tree_type{partition2},
  };

  // Verify sizes of two largest leaf partitions.
  const auto top_two = FindLargestPartitions(tree, 2);
  EXPECT_EQ(top_two[0]->Size(), 3);
  EXPECT_EQ(top_two[0]->TokensRange().front().Text(), "two");
  EXPECT_EQ(top_two[1]->Size(), 2);
  EXPECT_EQ(top_two[1]->TokensRange().front().Text(), "five");
}

class FlushLeftSpacingDifferencesTest : public TokenPartitionTreeTestFixture {};

TEST_F(FlushLeftSpacingDifferencesTest, EmptyPartitions) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  TokenPartitionTree tree{all};  // no children
  const TokenPartitionRange range(tree.Children().begin(),
                                  tree.Children().end());
  using V = std::vector<int>;
  const std::vector<V> diffs(FlushLeftSpacingDifferences(range));
  EXPECT_THAT(diffs, ElementsAre());
}

TEST_F(FlushLeftSpacingDifferencesTest, OnePartitionsOneToken) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(begin + 1);
  UnwrappedLine partition0(0, begin);
  partition0.SpanUpToToken(begin + 1);
  using T = TokenPartitionTree;
  T tree{partition0, T{partition0}};  // one partition, one token
  const TokenPartitionRange range(tree.Children().begin(),
                                  tree.Children().end());
  using V = std::vector<int>;
  const std::vector<V> diffs(FlushLeftSpacingDifferences(range));
  EXPECT_THAT(diffs, ElementsAre(V()));
}

TEST_F(FlushLeftSpacingDifferencesTest, OnePartitionsTwoTokens) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(begin + 2);
  UnwrappedLine partition0(0, begin);
  partition0.SpanUpToToken(begin + 2);
  using T = TokenPartitionTree;
  T tree{partition0, T{partition0}};  // one partition, two tokens
  const TokenPartitionRange range(tree.Children().begin(),
                                  tree.Children().end());
  using V = std::vector<int>;
  const std::vector<V> diffs(FlushLeftSpacingDifferences(range));
  EXPECT_THAT(diffs, ElementsAre(V({0})));
}

TEST_F(FlushLeftSpacingDifferencesTest, TwoPartitionsOneTokenEach) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(begin + 2);
  UnwrappedLine partition0(0, begin);
  partition0.SpanUpToToken(begin + 1);
  UnwrappedLine partition1(0, begin + 1);
  partition1.SpanUpToToken(begin + 2);
  using T = TokenPartitionTree;
  T tree{partition0, T{partition0}, T{partition1}};  // two partitions
  const TokenPartitionRange range(tree.Children().begin(),
                                  tree.Children().end());
  using V = std::vector<int>;
  const std::vector<V> diffs(FlushLeftSpacingDifferences(range));
  EXPECT_THAT(diffs, ElementsAre(V(), V()));
}

TEST_F(FlushLeftSpacingDifferencesTest, TwoPartitionsTwoTokensEach) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(begin + 4);
  UnwrappedLine partition0(0, begin);
  partition0.SpanUpToToken(begin + 2);
  UnwrappedLine partition1(0, begin + 2);
  partition1.SpanUpToToken(begin + 4);
  using T = TokenPartitionTree;
  T tree{partition0, T{partition0}, T{partition1}};  // two partitions
  const TokenPartitionRange range(tree.Children().begin(),
                                  tree.Children().end());
  using V = std::vector<int>;
  const std::vector<V> diffs(FlushLeftSpacingDifferences(range));
  EXPECT_THAT(diffs, ElementsAre(V({0}), V({0})));
}

class TokenPartitionTreePrinterTest : public TokenPartitionTreeTestFixture {};

// Verify specialized tree printing of UnwrappedLines.
TEST_F(TokenPartitionTreePrinterTest, VectorTreeShallow) {
  // Construct three partitions, sizes: 1, 3, 2
  // Change some attributes that will appear in the verbose rendition.
  pre_format_tokens_[2].before.spaces_required = 1;
  pre_format_tokens_[3].before.break_decision = SpacingOptions::MustAppend;
  pre_format_tokens_[4].before.break_penalty = 22;
  pre_format_tokens_[5].before.break_decision = SpacingOptions::MustWrap;
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine partition0(2, begin);
  partition0.SpanUpToToken(begin + 1);
  UnwrappedLine partition1(2, partition0.TokensRange().end());
  partition1.SpanUpToToken(begin + 4);
  UnwrappedLine partition2(2, partition1.TokensRange().end());
  partition2.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{partition0},
      tree_type{partition1},
      tree_type{partition2},
  };

  {
    std::ostringstream stream;
    stream << TokenPartitionTreePrinter(tree);
    EXPECT_EQ(stream.str(), R"({ ([<auto>], policy: uninitialized) @{}
  { (>>[one], policy: uninitialized) }
  { (>>[two three four], policy: uninitialized) }
  { (>>[five six], policy: uninitialized) }
})");
  }
  {
    std::ostringstream stream;
    stream << TokenPartitionTreePrinter(tree, true);  // verbose
    EXPECT_EQ(stream.str(), R"({ ([<auto>], policy: uninitialized) @{}
  { (>>[<_0,0>one], policy: uninitialized) }
  { (>>[<_0,0>two <_1,0>three <+_0>four], policy: uninitialized) }
  { (>>[<_0,22>five <\n>six], policy: uninitialized) }
})");
  }
}

TEST_F(TokenPartitionTreePrinterTest, VectorTreeDeep) {
  // Construct partitions, sizes: 1, (2, 1), (1, 1)
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine partition0(2, begin);
  partition0.SpanUpToToken(begin + 1);
  UnwrappedLine partition1(2, partition0.TokensRange().end());
  partition1.SpanUpToToken(begin + 4);
  UnwrappedLine partition1a(4, partition1.TokensRange().begin());
  partition1a.SpanUpToToken(begin + 3);
  UnwrappedLine partition1b(4, partition1a.TokensRange().end());
  partition1b.SpanUpToToken(begin + 4);
  UnwrappedLine partition2(2, partition1.TokensRange().end());
  partition2.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine partition2a(4, partition2.TokensRange().begin());
  partition2a.SpanUpToToken(begin + 5);
  UnwrappedLine partition2b(4, partition2a.TokensRange().end());
  partition2b.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{partition0},
      tree_type{
          partition1,
          tree_type{partition1a},
          tree_type{partition1b},
      },
      tree_type{
          partition2,
          tree_type{partition2a},
          tree_type{partition2b},
      },
  };

  std::ostringstream stream;
  stream << TokenPartitionTreePrinter(tree);
  EXPECT_EQ(stream.str(), R"({ ([<auto>], policy: uninitialized) @{}
  { (>>[one], policy: uninitialized) }
  { (>>[<auto>], policy: uninitialized) @{1}
    { (>>>>[two three], policy: uninitialized) }
    { (>>>>[four], policy: uninitialized) }
  }
  { (>>[<auto>], policy: uninitialized) @{2}
    { (>>>>[five], policy: uninitialized) }
    { (>>>>[six], policy: uninitialized) }
  }
})");
}

class AdjustIndentationTest : public TokenPartitionTreeTestFixture {};

TEST_F(AdjustIndentationTest, Relative) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(5, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine sub(7, begin);
  sub.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,             //
      tree_type{sub},  // same range, but indented more
  };
  EXPECT_EQ(tree.Value().IndentationSpaces(), 5);
  EXPECT_EQ(tree.Children().front().Value().IndentationSpaces(), 7);

  AdjustIndentationRelative(&tree, 1);
  EXPECT_EQ(tree.Value().IndentationSpaces(), 6);
  EXPECT_EQ(tree.Children().front().Value().IndentationSpaces(), 8);

  AdjustIndentationRelative(&tree, -3);
  EXPECT_EQ(tree.Value().IndentationSpaces(), 3);
  EXPECT_EQ(tree.Children().front().Value().IndentationSpaces(), 5);

  AdjustIndentationRelative(&tree, -4);
  EXPECT_EQ(tree.Value().IndentationSpaces(), 0);  // clamped at 0
  EXPECT_EQ(tree.Children().front().Value().IndentationSpaces(), 1);
}

TEST_F(AdjustIndentationTest, Absolute) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(5, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine sub(7, begin);
  sub.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,             //
      tree_type{sub},  // same range, but indented more
  };
  EXPECT_EQ(tree.Value().IndentationSpaces(), 5);
  EXPECT_EQ(tree.Children().front().Value().IndentationSpaces(), 7);

  AdjustIndentationAbsolute(&tree, 5);  // no change
  EXPECT_EQ(tree.Value().IndentationSpaces(), 5);
  EXPECT_EQ(tree.Children().front().Value().IndentationSpaces(), 7);

  AdjustIndentationAbsolute(&tree, 8);
  EXPECT_EQ(tree.Value().IndentationSpaces(), 8);
  EXPECT_EQ(tree.Children().front().Value().IndentationSpaces(), 10);

  AdjustIndentationAbsolute(&tree, 0);
  EXPECT_EQ(tree.Value().IndentationSpaces(), 0);
  EXPECT_EQ(tree.Children().front().Value().IndentationSpaces(), 2);
}

static bool PropertiesEqual(const UnwrappedLine& left,
                            const UnwrappedLine& right) {
  return (left.TokensRange() == right.TokensRange() &&
          left.IndentationSpaces() == right.IndentationSpaces() &&
          left.PartitionPolicy() == right.PartitionPolicy());
}

class GroupLeafWithPreviousLeafTest : public TokenPartitionTreeTestFixture {};

TEST_F(GroupLeafWithPreviousLeafTest, RootOnly) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
  };

  const auto saved_tree(tree);  // deep copy
  auto* group = GroupLeafWithPreviousLeaf(&tree);
  EXPECT_EQ(group, nullptr);

  // Expect no change.
  const auto diff = DeepEqual(tree, saved_tree, PropertiesEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(GroupLeafWithPreviousLeafTest, OneChild) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all, tree_type{all},  // subtree spans same range
  };
  ASSERT_FALSE(is_leaf(tree));

  const auto saved_tree(tree);  // deep copy
  auto* group = GroupLeafWithPreviousLeaf(&tree.Children().front());
  EXPECT_EQ(group, nullptr);

  // Expect no change.
  const auto diff = DeepEqual(tree, saved_tree, PropertiesEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(GroupLeafWithPreviousLeafTest, TwoChild) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  part1.SetIndentationSpaces(4);
  part1.SetPartitionPolicy(PartitionPolicyEnum::kAlwaysExpand);
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());
  part2.SetIndentationSpaces(2);
  part2.SetPartitionPolicy(PartitionPolicyEnum::kFitOnLineElseExpand);

  UnwrappedLine group_part(0, begin);
  group_part.SpanUpToToken(preformat_tokens.end());
  group_part.SetIndentationSpaces(4);
  group_part.SetPartitionPolicy(PartitionPolicyEnum::kAlwaysExpand);

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{part1},
      tree_type{part2},
  };

  const tree_type expected_tree{
      all,
      tree_type{
          group_part,
          tree_type{part1},
          tree_type{part2},
      },
  };

  auto* group = GroupLeafWithPreviousLeaf(&tree.Children().back());
  EXPECT_EQ(group, &tree.Children().back());

  const auto diff = DeepEqual(tree, expected_tree, PropertiesEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(GroupLeafWithPreviousLeafTest, TwoGenerations) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  UnwrappedLine part1a(0, begin);
  part1a.SpanUpToToken(begin + 2);
  UnwrappedLine part1b(0, part1a.TokensRange().end());
  part1b.SpanUpToToken(part1.TokensRange().end());
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());

  // New expected partition should be part1b + part2
  UnwrappedLine group_part(0, part1b.TokensRange().begin());
  group_part.SpanUpToToken(all.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{
          part1, tree_type{part1a},  // unchanged
          tree_type{part1b},         // target partition
      },
      tree_type{part2},  // source partition
  };

  const tree_type expected_tree{
      all,
      tree_type{
          all,
          tree_type{part1a},
          tree_type{
              group_part, tree_type{part1b},  // target partition
              tree_type{part2},               // source partition
          },
      },
  };

  auto* group = GroupLeafWithPreviousLeaf(&tree.Children().back());
  EXPECT_EQ(group, &tree.Children().back().Children().back());

  const auto diff = DeepEqual(tree, expected_tree, PropertiesEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(GroupLeafWithPreviousLeafTest, Cousins) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  UnwrappedLine part1a(0, begin);
  part1a.SpanUpToToken(begin + 2);
  UnwrappedLine part1b(0, part1a.TokensRange().end());
  part1b.SpanUpToToken(part1.TokensRange().end());
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());
  UnwrappedLine part2a(0, part2.TokensRange().begin());
  part2a.SpanUpToToken(part2.TokensRange().begin() + 1);
  UnwrappedLine part2b(0, part2a.TokensRange().end());
  part2b.SpanUpToToken(all.TokensRange().end());

  // New expected partition should be part1b + part2a
  UnwrappedLine group_part(0, part1b.TokensRange().begin());
  group_part.SpanUpToToken(part2a.TokensRange().end());
  UnwrappedLine group_parent(0, begin);
  group_parent.SpanUpToToken(part2a.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{
          part1, tree_type{part1a},  // unchanged
          tree_type{part1b},         // target partition
      },
      tree_type{
          part2,
          tree_type{part2a},  // source partition
          tree_type{part2b},
      },
  };

  const tree_type expected_tree{
      all,
      tree_type{
          group_parent,
          tree_type{part1a},
          tree_type{
              group_part, tree_type{part1b},  // target partition
              tree_type{part2a},              // source partition
          },
      },
      tree_type{
          part2b,
          tree_type{part2b},
      },
  };

  auto* group =
      GroupLeafWithPreviousLeaf(&tree.Children().back().Children().front());
  EXPECT_EQ(group, &tree.Children().front().Children().back());

  const auto diff = DeepEqual(tree, expected_tree, PropertiesEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(GroupLeafWithPreviousLeafTest, ExtendCommonAncestor) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 1);
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(part1.TokensRange().end() + 1);
  UnwrappedLine part3(0, part2.TokensRange().end());
  part3.SpanUpToToken(all.TokensRange().end());

  // New expected partition should be part2 + part3
  UnwrappedLine group_part(0, part2.TokensRange().begin());
  group_part.SpanUpToToken(part3.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      part1,
      tree_type{part1},
      tree_type{part2},
      tree_type{part3},
  };

  const tree_type expected_tree{
      all,
      tree_type{part1},
      tree_type{
          group_part,
          tree_type{part2},
          tree_type{part3},
      },
  };

  auto* group = GroupLeafWithPreviousLeaf(&tree.Children().back());
  EXPECT_EQ(group, &tree.Children().back());

  const auto diff = DeepEqual(tree, expected_tree, PropertiesEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

static bool TokenRangeEqual(const UnwrappedLine& left,
                            const UnwrappedLine& right) {
  return left.TokensRange() == right.TokensRange();
}

class MergeLeafIntoPreviousLeafTest : public TokenPartitionTreeTestFixture {};

TEST_F(MergeLeafIntoPreviousLeafTest, RootOnly) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
  };

  const auto saved_tree(tree);  // deep copy
  auto* parent = MergeLeafIntoPreviousLeaf(&tree);
  EXPECT_EQ(parent, nullptr);

  // Expect no change.
  const auto diff = DeepEqual(tree, saved_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(MergeLeafIntoPreviousLeafTest, OneChild) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all, tree_type{all},  // subtree spans same range
  };
  ASSERT_FALSE(is_leaf(tree));

  const auto saved_tree(tree);  // deep copy
  auto* parent = MergeLeafIntoPreviousLeaf(&tree.Children().front());
  EXPECT_EQ(parent, nullptr);

  // Expect no change.
  const auto diff = DeepEqual(tree, saved_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(MergeLeafIntoPreviousLeafTest, TwoChild) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{part1},
      tree_type{part2},
  };

  const tree_type expected_tree{
      all,
      tree_type{all},
  };

  auto* parent = MergeLeafIntoPreviousLeaf(&tree.Children().back());
  EXPECT_EQ(parent, &tree);

  const auto diff = DeepEqual(tree, expected_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(MergeLeafIntoPreviousLeafTest, TwoGenerations) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  UnwrappedLine part1a(0, begin);
  part1a.SpanUpToToken(begin + 2);
  UnwrappedLine part1b(0, part1a.TokensRange().end());
  part1b.SpanUpToToken(part1.TokensRange().end());
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());

  // New expected partition should be part1b + part2
  UnwrappedLine fused_part(0, part1b.TokensRange().begin());
  fused_part.SpanUpToToken(all.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{
          part1, tree_type{part1a},  // unchanged
          tree_type{part1b},         // target partition
      },
      tree_type{part2},  // source partition
  };

  const tree_type expected_tree{
      all,
      tree_type{
          all, tree_type{part1a},
          tree_type{fused_part},  // fused target partition
      },
  };

  auto* parent = MergeLeafIntoPreviousLeaf(&tree.Children().back());
  EXPECT_EQ(parent, &tree);

  const auto diff = DeepEqual(tree, expected_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(MergeLeafIntoPreviousLeafTest, Cousins) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  UnwrappedLine part1a(0, begin);
  part1a.SpanUpToToken(begin + 2);
  UnwrappedLine part1b(0, part1a.TokensRange().end());
  part1b.SpanUpToToken(part1.TokensRange().end());
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());
  UnwrappedLine part2a(0, part2.TokensRange().begin());
  part2a.SpanUpToToken(part2.TokensRange().begin() + 1);
  UnwrappedLine part2b(0, part2a.TokensRange().end());
  part2b.SpanUpToToken(all.TokensRange().end());

  // New expected partition should be part1b + part2a
  UnwrappedLine fused_part(0, part1b.TokensRange().begin());
  fused_part.SpanUpToToken(part2a.TokensRange().end());
  UnwrappedLine fused_parent(0, begin);
  fused_parent.SpanUpToToken(part2a.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{
          part1, tree_type{part1a},  // unchanged
          tree_type{part1b},         // target partition
      },
      tree_type{
          part2,
          tree_type{part2a},  // source partition
          tree_type{part2b},
      },
  };

  const tree_type expected_tree{
      all,
      tree_type{
          fused_parent, tree_type{part1a},
          tree_type{fused_part},  // fused target partition
      },
      tree_type{
          part2b,
          tree_type{part2b},
      },
  };

  auto* parent =
      MergeLeafIntoPreviousLeaf(&tree.Children().back().Children().front());
  EXPECT_EQ(parent, &tree.Children().back());

  const auto diff = DeepEqual(tree, expected_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

class MergeLeafIntoNextLeafTest : public TokenPartitionTreeTestFixture {};

TEST_F(MergeLeafIntoNextLeafTest, RootOnly) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
  };

  const auto saved_tree(tree);  // deep copy
  auto* parent = MergeLeafIntoNextLeaf(&tree);
  EXPECT_EQ(parent, nullptr);

  // Expect no change.
  const auto diff = DeepEqual(tree, saved_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(MergeLeafIntoNextLeafTest, OneChild) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all, tree_type{all},  // subtree spans same range
  };
  ASSERT_FALSE(is_leaf(tree));

  const auto saved_tree(tree);  // deep copy
  auto* parent = MergeLeafIntoNextLeaf(&tree.Children().front());
  EXPECT_EQ(parent, nullptr);

  // Expect no change.
  const auto diff = DeepEqual(tree, saved_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(MergeLeafIntoNextLeafTest, TwoChild) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{part1},
      tree_type{part2},
  };

  const tree_type expected_tree{
      all,
      tree_type{all},
  };

  auto* parent = MergeLeafIntoNextLeaf(&tree.Children().front());
  EXPECT_EQ(parent, &tree);

  const auto diff = DeepEqual(tree, expected_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(MergeLeafIntoNextLeafTest, TwoGenerations) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  UnwrappedLine part1a(0, begin);
  part1a.SpanUpToToken(begin + 2);
  UnwrappedLine part1b(0, part1a.TokensRange().end());
  part1b.SpanUpToToken(part1.TokensRange().end());
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());

  // New expected partition should be part1b + part2
  UnwrappedLine fused_part(0, part1b.TokensRange().begin());
  fused_part.SpanUpToToken(all.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{
          part1, tree_type{part1a},  // unchanged
          tree_type{part1b},         // origin partition
      },
      tree_type{part2},  // target partition
  };

  const tree_type expected_tree{
      all,
      tree_type{
          part1a,
          tree_type{part1a},
      },
      tree_type{fused_part},  // fused target partition
  };

  auto* parent =
      MergeLeafIntoNextLeaf(&tree.Children().front().Children().back());
  EXPECT_EQ(parent, &tree.Children().front());

  const auto diff = DeepEqual(tree, expected_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(MergeLeafIntoNextLeafTest, Cousins) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  UnwrappedLine part1a(0, begin);
  part1a.SpanUpToToken(begin + 2);
  UnwrappedLine part1b(0, part1a.TokensRange().end());
  part1b.SpanUpToToken(part1.TokensRange().end());
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());
  UnwrappedLine part2a(0, part2.TokensRange().begin());
  part2a.SpanUpToToken(part2.TokensRange().begin() + 1);
  UnwrappedLine part2b(0, part2a.TokensRange().end());
  part2b.SpanUpToToken(all.TokensRange().end());

  // New expected partition should be part1b + part2a
  UnwrappedLine fused_part(0, part1b.TokensRange().begin());
  fused_part.SpanUpToToken(part2a.TokensRange().end());
  UnwrappedLine fused_parent(0, part1b.TokensRange().begin());
  fused_parent.SpanUpToToken(all.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{
          part1, tree_type{part1a},  // unchanged
          tree_type{part1b},         // source partition
      },
      tree_type{
          part2,
          tree_type{part2a},  // target partition
          tree_type{part2b},
      },
  };

  const tree_type expected_tree{
      all,
      tree_type{
          part1a,
          tree_type{part1a},
      },
      tree_type{
          fused_parent,
          tree_type{fused_part},  // fused target partition
          tree_type{part2b},
      },
  };

  auto* parent =
      MergeLeafIntoNextLeaf(&tree.Children().front().Children().back());
  EXPECT_EQ(parent, &tree.Children().front());

  const auto diff = DeepEqual(tree, expected_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

class MergeConsecutiveSiblingsTest : public TokenPartitionTreeTestFixture {};

TEST_F(MergeConsecutiveSiblingsTest, OneChild) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all, tree_type{all},  // subtree spans same range
  };

  // Need at least 2 sliblings to join.
  EXPECT_DEATH(MergeConsecutiveSiblings(&tree, 0), "");
}

TEST_F(MergeConsecutiveSiblingsTest, TwoChild) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{part1},
      tree_type{part2},
  };

  const tree_type expected_tree{
      all, tree_type{all},  // concatenated unwrapped line ranges
  };

  MergeConsecutiveSiblings(&tree, 0);
  const auto diff = DeepEqual(tree, expected_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

TEST_F(MergeConsecutiveSiblingsTest, TwoGenerations) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  // Construct an artificial tree using the following partitions.
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine part1(0, begin);
  part1.SpanUpToToken(begin + 3);
  UnwrappedLine part1a(0, begin);
  part1a.SpanUpToToken(begin + 2);
  UnwrappedLine part1b(0, part1a.TokensRange().end());
  part1b.SpanUpToToken(part1.TokensRange().end());
  UnwrappedLine part2(0, part1.TokensRange().end());
  part2.SpanUpToToken(all.TokensRange().end());
  UnwrappedLine part2a(0, begin);
  part2a.SpanUpToToken(begin + 1);
  UnwrappedLine part2b(0, part1a.TokensRange().end());
  part2b.SpanUpToToken(part2.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{
          part1,
          tree_type{part1a},
          tree_type{part1b},
      },
      tree_type{
          part2,
          tree_type{part2a},
          tree_type{part2b},
      },
  };

  const tree_type expected_tree{
      all,
      tree_type{
          all,  // part1 + part2
          // children of part1 and part2 are concatenated
          tree_type{part1a},
          tree_type{part1b},
          tree_type{part2a},
          tree_type{part2b},
      },
  };

  MergeConsecutiveSiblings(&tree, 0);
  const auto diff = DeepEqual(tree, expected_tree, TokenRangeEqual);
  EXPECT_TRUE(diff.left == nullptr) << "First differing node at:\n"
                                    << *diff.left << "\nand:\n"
                                    << *diff.right << '\n';
}

class AnyPartitionSubRangeIsDisabledTest
    : public TokenPartitionTreeTestFixture {};

TEST_F(AnyPartitionSubRangeIsDisabledTest, Various) {
  // Construct three partitions, sizes: 1, 3, 2
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine partition0(0, begin);
  partition0.SpanUpToToken(begin + 1);
  UnwrappedLine partition1(0, partition0.TokensRange().end());
  partition1.SpanUpToToken(begin + 4);
  UnwrappedLine partition2(0, partition1.TokensRange().end());
  partition2.SpanUpToToken(preformat_tokens.end());
  ASSERT_EQ(partition2.TokensRange().size(), 2);

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{partition0},
      tree_type{partition1},
      tree_type{partition2},
  };

  {
    const TokenPartitionRange empty(tree.Children().begin(),
                                    tree.Children().begin());
    EXPECT_FALSE(AnyPartitionSubRangeIsDisabled(empty, joined_token_text_,
                                                ByteOffsetSet{}));
  }
  {
    const TokenPartitionRange range(tree.Children().begin(),
                                    tree.Children().end());
    EXPECT_FALSE(AnyPartitionSubRangeIsDisabled(range, joined_token_text_,
                                                ByteOffsetSet{}));
    EXPECT_TRUE(AnyPartitionSubRangeIsDisabled(range, joined_token_text_,
                                               ByteOffsetSet{{0, 1}}));
    EXPECT_TRUE(AnyPartitionSubRangeIsDisabled(range, joined_token_text_,
                                               ByteOffsetSet{{10, 20}}));
    EXPECT_TRUE(AnyPartitionSubRangeIsDisabled(range, joined_token_text_,
                                               ByteOffsetSet{{21, 22}}));
    EXPECT_FALSE(AnyPartitionSubRangeIsDisabled(range, joined_token_text_,
                                                ByteOffsetSet{{22, 23}}));
    EXPECT_FALSE(AnyPartitionSubRangeIsDisabled(range, joined_token_text_,
                                                ByteOffsetSet{{30, 40}}));
    EXPECT_TRUE(AnyPartitionSubRangeIsDisabled(
        range, joined_token_text_, ByteOffsetSet{{5, 6}, {30, 40}}));
  }
}

class GetSubpartitionsBetweenBlankLinesTest
    : public ::testing::Test,
      public UnwrappedLineMemoryHandler {
 public:
  explicit GetSubpartitionsBetweenBlankLinesTest(absl::string_view text)
      : sample_(text),
        tokens_(
            absl::StrSplit(sample_, absl::ByAnyChar(" \n"), absl::SkipEmpty())),
        partition_(/* temporary */ UnwrappedLine()) {
    CHECK_EQ(tokens_.size(), 8);
    for (const auto token : tokens_) {
      ftokens_.emplace_back(TokenInfo{1, token});
    }
    // sample_ is the memory-owning string buffer
    CreateTokenInfosExternalStringBuffer(ftokens_);

    // Establish format token ranges per partition.
    const auto& preformat_tokens = pre_format_tokens_;
    const auto begin = preformat_tokens.begin();
    UnwrappedLine all(0, begin);
    all.SpanUpToToken(preformat_tokens.end());
    UnwrappedLine child1(0, begin);
    child1.SpanUpToToken(begin + 2);
    UnwrappedLine child2(0, begin + 2);
    child2.SpanUpToToken(begin + 4);
    UnwrappedLine child3(0, begin + 4);
    child3.SpanUpToToken(begin + 6);
    UnwrappedLine child4(0, begin + 6);
    child4.SpanUpToToken(begin + 8);

    // Construct 2-level token partition.
    using tree_type = TokenPartitionTree;
    partition_ = tree_type{
        all,
        tree_type{child1},
        tree_type{child2},
        tree_type{child3},
        tree_type{child4},
    };
  }

 protected:
  const std::string sample_;
  const std::vector<absl::string_view> tokens_;
  std::vector<TokenInfo> ftokens_;
  TokenPartitionTree partition_;
};

class GetSubpartitionsNoNewlinesTest
    : public GetSubpartitionsBetweenBlankLinesTest {
 public:
  GetSubpartitionsNoNewlinesTest()
      : GetSubpartitionsBetweenBlankLinesTest(
            "one two three four five seven six eight") {}
};

TEST_F(GetSubpartitionsNoNewlinesTest, NoNewlines) {
  const TokenPartitionRange range(partition_.Children().begin(),
                                  partition_.Children().end());
  const auto partition_ranges = GetSubpartitionsBetweenBlankLines(range);
  EXPECT_THAT(partition_ranges,
              ElementsAre(TokenPartitionRange(range.begin(), range.end())));
}

class GetSubpartitionsNoBlanksTest
    : public GetSubpartitionsBetweenBlankLinesTest {
 public:
  GetSubpartitionsNoBlanksTest()
      : GetSubpartitionsBetweenBlankLinesTest(
            "one two three\nfour five seven\nsix eight") {}
};

TEST_F(GetSubpartitionsNoBlanksTest, NoBlanks) {
  const TokenPartitionRange range(partition_.Children().begin(),
                                  partition_.Children().end());
  const auto partition_ranges = GetSubpartitionsBetweenBlankLines(range);
  EXPECT_THAT(partition_ranges,
              ElementsAre(TokenPartitionRange(range.begin(), range.end())));
}

class GetSubpartitionsWithBlanksTest
    : public GetSubpartitionsBetweenBlankLinesTest {
 public:
  GetSubpartitionsWithBlanksTest()
      : GetSubpartitionsBetweenBlankLinesTest(
            "one two\n\nthree four five seven\n\nsix eight") {}
};

TEST_F(GetSubpartitionsWithBlanksTest, WithBlanks) {
  const TokenPartitionRange range(partition_.Children().begin(),
                                  partition_.Children().end());
  const auto partition_ranges = GetSubpartitionsBetweenBlankLines(range);
  EXPECT_THAT(
      partition_ranges,
      ElementsAre(TokenPartitionRange(range.begin(), range.begin() + 1),
                  TokenPartitionRange(range.begin() + 1, range.begin() + 3),
                  TokenPartitionRange(range.begin() + 3, range.begin() + 4)));
}

class IndentButPreserveOtherSpacingTest : public TokenPartitionTreeTestFixture {
};

TEST_F(IndentButPreserveOtherSpacingTest, Various) {
  // Construct three partitions, sizes: 1, 3, 2
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();
  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());
  UnwrappedLine partition0(0, begin);
  partition0.SpanUpToToken(begin + 1);
  UnwrappedLine partition1(0, partition0.TokensRange().end());
  partition1.SpanUpToToken(begin + 4);
  UnwrappedLine partition2(0, partition1.TokensRange().end());
  partition2.SpanUpToToken(preformat_tokens.end());

  // Construct an artificial tree using the above partitions.
  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{partition0},
      tree_type{partition1},
      tree_type{partition2},
  };

  const TokenPartitionRange range(tree.Children().begin(),
                                  tree.Children().end());
  IndentButPreserveOtherSpacing(range, joined_token_text_, &pre_format_tokens_);
  // The first tokens on each partition need not be preserved, but all
  // subsequent tokens should be preserved.
  for (const auto& child : range) {
    auto token_range = child.Value().TokensRange();
    if (token_range.empty()) continue;
    token_range.pop_front();
    for (const auto& ftoken : token_range) {
      EXPECT_EQ(ftoken.before.break_decision, SpacingOptions::Preserve);
    }
  }
}

class ReshapeFittingSubpartitionsTest : public TokenPartitionTreeTestFixture {};

TEST_F(ReshapeFittingSubpartitionsTest, NoArguments) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);

  using tree_type = TokenPartitionTree;
  tree_type tree{
      header,
      tree_type{header},
  };

  const tree_type tree_expected{
      header,
      tree_type{header},
  };

  verible::BasicFormatStyle style;  // default
  ReshapeFittingSubpartitions(style, &tree);

  // Check tree structure
  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
}

TEST_F(ReshapeFittingSubpartitionsTest, OneArgumentInSubpartition) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);
  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);

  UnwrappedLine all(0, begin);
  all.SpanUpToToken(arg1.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          arg1,
          tree_type{arg1},
      },
  };

  const tree_type tree_expected{
      all,
      tree_type{
          all,
          tree_type{header},
          tree_type{arg1},
      },
  };

  verible::BasicFormatStyle style;  // default
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
}

TEST_F(ReshapeFittingSubpartitionsTest, OneArgumentInSubpartitionAndTrailer) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanNextToken();
  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine trailer(0, arg1.TokensRange().end());
  trailer.SpanNextToken();

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(trailer.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          arg1,
          tree_type{arg1},
      },
      tree_type{trailer},
  };

  const tree_type tree_expected{
      all,
      tree_type{
          all,
          tree_type{header},
          tree_type{arg1},
          tree_type{trailer},
      },
  };

  verible::BasicFormatStyle style;  // default
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
}

TEST_F(ReshapeFittingSubpartitionsTest, OneArgumentFlat) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);
  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);

  UnwrappedLine all(0, begin);
  all.SpanUpToToken(arg1.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all, tree_type{header}, tree_type{arg1},  // flat, not in subpartition
  };

  const tree_type tree_expected{
      all,
      tree_type{
          all,
          tree_type{header},
          tree_type{arg1},
      },
  };

  verible::BasicFormatStyle style;  // default
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
}

TEST_F(ReshapeFittingSubpartitionsTest, OneArgumentFlatAndTrailer) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanNextToken();
  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine trailer(0, arg1.TokensRange().end());
  trailer.SpanNextToken();

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(trailer.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{arg1},  // flat, not in subpartition
      tree_type{trailer},
  };

  const tree_type tree_expected{
      all,
      tree_type{
          all,
          tree_type{header},
          tree_type{arg1},
          tree_type{trailer},
      },
  };

  verible::BasicFormatStyle style;  // default
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
}

TEST_F(ReshapeFittingSubpartitionsTest, TwoArguments) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);

  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanUpToToken(begin + 3);

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg2.TokensRange().end());

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(arg2.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
      },
  };

  const tree_type tree_expected{
      all,
      tree_type{
          all,
          tree_type{header},
          tree_type{arg1},
          tree_type{arg2},
      },
  };

  verible::BasicFormatStyle style;  // default
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
}

TEST_F(ReshapeFittingSubpartitionsTest, TwoArgumentsAndTrailer) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanNextToken();

  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanNextToken();

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg2.TokensRange().end());

  UnwrappedLine trailer(0, args.TokensRange().end());
  trailer.SpanNextToken();

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(trailer.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
      },
      tree_type{trailer},
  };

  const tree_type tree_expected{
      all,
      tree_type{
          all,
          tree_type{header},
          tree_type{arg1},
          tree_type{arg2},
          tree_type{trailer},
      },
  };

  verible::BasicFormatStyle style;  // default
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
}

// All fits in one partition
TEST_F(ReshapeFittingSubpartitionsTest, OnePartition) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);

  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanUpToToken(begin + 3);
  UnwrappedLine arg3(0, arg2.TokensRange().end());
  arg3.SpanUpToToken(begin + 4);
  UnwrappedLine arg4(0, arg3.TokensRange().end());
  arg4.SpanUpToToken(begin + 5);
  UnwrappedLine arg5(0, arg4.TokensRange().end());
  arg5.SpanUpToToken(begin + 6);

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg5.TokensRange().end());

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(arg5.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
      },
  };

  const tree_type tree_expected{
      all,
      tree_type{
          all,
          tree_type{header},
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
      },
  };

  verible::BasicFormatStyle style;  // default
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
}

// All fits in one partition
TEST_F(ReshapeFittingSubpartitionsTest, OnePartitionWithTrailer) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanNextToken();

  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanNextToken();
  UnwrappedLine arg3(0, arg2.TokensRange().end());
  arg3.SpanNextToken();
  UnwrappedLine arg4(0, arg3.TokensRange().end());
  arg4.SpanNextToken();

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg4.TokensRange().end());

  UnwrappedLine trailer(0, args.TokensRange().end());
  trailer.SpanNextToken();

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(trailer.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
      },
      tree_type{trailer},
  };

  const tree_type tree_expected{
      all,
      tree_type{
          all,
          tree_type{header},
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{trailer},
      },
  };

  verible::BasicFormatStyle style;  // default
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
}

// Wrap into two partitions
TEST_F(ReshapeFittingSubpartitionsTest, TwoPartitions) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);

  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanUpToToken(begin + 3);
  UnwrappedLine arg3(0, arg2.TokensRange().end());
  arg3.SpanUpToToken(begin + 4);
  UnwrappedLine arg4(0, arg3.TokensRange().end());
  arg4.SpanUpToToken(begin + 5);
  UnwrappedLine arg5(0, arg4.TokensRange().end());
  arg5.SpanUpToToken(begin + 6);

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg5.TokensRange().end());

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(arg5.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
      },
  };

  UnwrappedLine group1(0, header.TokensRange().begin());
  group1.SpanUpToToken(arg2.TokensRange().end());
  UnwrappedLine group2(0, arg3.TokensRange().begin());
  group2.SpanUpToToken(arg5.TokensRange().end());

  const tree_type tree_expected{
      all,
      tree_type{
          group1,
          tree_type{header},
          tree_type{arg1},
          tree_type{arg2},
      },
      tree_type{
          group2,
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
      },
  };

  verible::BasicFormatStyle style;  // default
  style.column_limit = 14;
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
  EXPECT_EQ(
      tree.Children()[1].Value().IndentationSpaces(),
      header.TokensRange()[0].Length());  // indenation equal first token length
}

// Wrap into two partitions
TEST_F(ReshapeFittingSubpartitionsTest, TwoPartitionsWithTrailer) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanNextToken();

  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanNextToken();
  UnwrappedLine arg3(0, arg2.TokensRange().end());
  arg3.SpanNextToken();
  UnwrappedLine arg4(0, arg3.TokensRange().end());
  arg4.SpanNextToken();

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg4.TokensRange().end());

  UnwrappedLine trailer(0, args.TokensRange().end());
  trailer.SpanNextToken();

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(trailer.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
      },
      tree_type{trailer},
  };

  UnwrappedLine group1(0, header.TokensRange().begin());
  group1.SpanUpToToken(arg2.TokensRange().end());
  UnwrappedLine group2(0, arg3.TokensRange().begin());
  group2.SpanUpToToken(trailer.TokensRange().end());

  const tree_type tree_expected{
      all,
      tree_type{
          group1,
          tree_type{header},
          tree_type{arg1},
          tree_type{arg2},
      },
      tree_type{
          group2,
          tree_type{arg3},
          tree_type{arg4},
          tree_type{trailer},
      },
  };

  verible::BasicFormatStyle style;  // default
  style.column_limit = 14;
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
  EXPECT_EQ(
      tree.Children()[1].Value().IndentationSpaces(),
      header.TokensRange()[0].Length());  // indenation equal first token length
}

// None fits
TEST_F(ReshapeFittingSubpartitionsTest, NoneOneFits) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);

  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanUpToToken(begin + 3);
  UnwrappedLine arg3(0, arg2.TokensRange().end());
  arg3.SpanUpToToken(begin + 4);
  UnwrappedLine arg4(0, arg3.TokensRange().end());
  arg4.SpanUpToToken(begin + 5);
  UnwrappedLine arg5(0, arg4.TokensRange().end());
  arg5.SpanUpToToken(begin + 6);

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg5.TokensRange().end());

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(arg5.TokensRange().end());

  verible::BasicFormatStyle style;  // default
  style.column_limit = 2;

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
      },
  };

  ApplyPreOrder(tree.Children()[1], [&style](TokenPartitionTree& node) {
    auto& uwline = node.Value();
    uwline.SetIndentationSpaces(style.wrap_spaces);
  });

  const tree_type tree_expected{
      all,
      tree_type{header, tree_type{header}},
      tree_type{arg1, tree_type{arg1}},
      tree_type{arg2, tree_type{arg2}},
      tree_type{arg3, tree_type{arg3}},
      tree_type{arg4, tree_type{arg4}},
      tree_type{arg5, tree_type{arg5}},
  };

  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
  EXPECT_EQ(tree.Children()[1].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[2].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[3].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[4].Value().IndentationSpaces(), style.wrap_spaces);
}

// None fits
TEST_F(ReshapeFittingSubpartitionsTest, NoneOneFitsWithTrailer) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  verible::BasicFormatStyle style;  // default
  style.column_limit = 2;

  UnwrappedLine header(0, begin);
  header.SpanNextToken();

  UnwrappedLine arg1(style.wrap_spaces, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine arg2(style.wrap_spaces, arg1.TokensRange().end());
  arg2.SpanNextToken();
  UnwrappedLine arg3(style.wrap_spaces, arg2.TokensRange().end());
  arg3.SpanNextToken();
  UnwrappedLine arg4(style.wrap_spaces, arg3.TokensRange().end());
  arg4.SpanNextToken();

  UnwrappedLine args(style.wrap_spaces, arg1.TokensRange().begin());
  args.SpanUpToToken(arg4.TokensRange().end());

  UnwrappedLine trailer(0, args.TokensRange().end());
  trailer.SpanNextToken();

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(trailer.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
      },
      tree_type{trailer},
  };

  const tree_type tree_expected{
      all,
      tree_type{header, tree_type{header}},
      tree_type{arg1, tree_type{arg1}},
      tree_type{arg2, tree_type{arg2}},
      tree_type{arg3, tree_type{arg3}},
      tree_type{arg4, tree_type{arg4}},
      tree_type{trailer, tree_type{trailer}},
  };

  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
  EXPECT_EQ(tree.Children()[1].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[2].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[3].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[4].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[5].Value().IndentationSpaces(), 0);
}

// All fits in one partition
TEST_F(ReshapeFittingSubpartitionsTest, IndentationOnePartition) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);

  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanUpToToken(begin + 3);
  UnwrappedLine arg3(0, arg2.TokensRange().end());
  arg3.SpanUpToToken(begin + 4);
  UnwrappedLine arg4(0, arg3.TokensRange().end());
  arg4.SpanUpToToken(begin + 5);
  UnwrappedLine arg5(0, arg4.TokensRange().end());
  arg5.SpanUpToToken(begin + 6);

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg5.TokensRange().end());

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(arg5.TokensRange().end());

  verible::BasicFormatStyle style;  // default

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
      },
  };

  ApplyPreOrder(tree.Children()[1], [&style](TokenPartitionTree& node) {
    auto& uwline = node.Value();
    uwline.SetIndentationSpaces(3 + style.indentation_spaces);
  });

  tree.Children()[0].Value().SetIndentationSpaces(3);
  tree.Value().SetIndentationSpaces(3);

  const tree_type tree_expected{
      all,
      tree_type{
          all,
          tree_type{header},
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
      },
  };

  auto saved_tree(tree);
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // keep orig indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(),
            saved_tree.Value().IndentationSpaces());
}

// All fits in one partition
TEST_F(ReshapeFittingSubpartitionsTest, IndentationOnePartitionWithTrailer) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  verible::BasicFormatStyle style;  // default

  UnwrappedLine header(3, begin);
  header.SpanNextToken();

  UnwrappedLine arg1(3 + style.indentation_spaces, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine arg2(3 + style.indentation_spaces, arg1.TokensRange().end());
  arg2.SpanNextToken();
  UnwrappedLine arg3(3 + style.indentation_spaces, arg2.TokensRange().end());
  arg3.SpanNextToken();
  UnwrappedLine arg4(3 + style.indentation_spaces, arg3.TokensRange().end());
  arg4.SpanNextToken();

  UnwrappedLine args(3 + style.indentation_spaces, arg1.TokensRange().begin());
  args.SpanUpToToken(arg4.TokensRange().end());

  UnwrappedLine trailer(3, args.TokensRange().end());
  trailer.SpanNextToken();

  UnwrappedLine all(3, header.TokensRange().begin());
  all.SpanUpToToken(trailer.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
      },
      tree_type{trailer},
  };

  const tree_type tree_expected{
      all,
      tree_type{
          all,
          tree_type{header},
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{trailer},
      },
  };

  auto saved_tree(tree);
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // keep orig indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(),
            saved_tree.Value().IndentationSpaces());
}

// Wrap into two partitions
TEST_F(ReshapeFittingSubpartitionsTest, IndentationTwoPartitions) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);

  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanUpToToken(begin + 3);
  UnwrappedLine arg3(0, arg2.TokensRange().end());
  arg3.SpanUpToToken(begin + 4);
  UnwrappedLine arg4(0, arg3.TokensRange().end());
  arg4.SpanUpToToken(begin + 5);
  UnwrappedLine arg5(0, arg4.TokensRange().end());
  arg5.SpanUpToToken(begin + 6);

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg5.TokensRange().end());

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(arg5.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
      },
  };

  verible::BasicFormatStyle style;  // default
  style.column_limit = 14 + 7;

  ApplyPreOrder(tree.Children()[1], [&style](TokenPartitionTree& node) {
    auto& uwline = node.Value();
    uwline.SetIndentationSpaces(7 + style.indentation_spaces);
  });

  tree.Children()[0].Value().SetIndentationSpaces(7);
  tree.Value().SetIndentationSpaces(7);

  UnwrappedLine group1(0, header.TokensRange().begin());
  group1.SpanUpToToken(arg2.TokensRange().end());
  UnwrappedLine group2(0, arg3.TokensRange().begin());
  group2.SpanUpToToken(arg5.TokensRange().end());

  const tree_type tree_expected{
      all,
      tree_type{
          group1,
          tree_type{header},
          tree_type{arg1},
          tree_type{arg2},
      },
      tree_type{
          group2,
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
      },
  };

  auto saved_tree(tree);
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check group nodes indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 7);
  EXPECT_EQ(tree.Children()[1].Value().IndentationSpaces(),
            header.TokensRange()[0].Length() + 7);  // appended

  EXPECT_EQ(saved_tree.Children()[0].Value().IndentationSpaces(),
            tree.Children()[0].Children()[0].Value().IndentationSpaces());
  EXPECT_EQ(tree.Children()[0].Children()[1].Value().IndentationSpaces(), 7);
  EXPECT_EQ(tree.Children()[0].Children()[2].Value().IndentationSpaces(), 7);

  EXPECT_EQ(tree.Children()[1].Children()[0].Value().IndentationSpaces(),
            header.TokensRange()[0].Length() + 7);  // appended
  EXPECT_EQ(tree.Children()[1].Children()[1].Value().IndentationSpaces(),
            header.TokensRange()[0].Length() + 7);  // appended
  EXPECT_EQ(tree.Children()[1].Children()[2].Value().IndentationSpaces(),
            header.TokensRange()[0].Length() + 7);  // appended
}

// Wrap into two partitions
TEST_F(ReshapeFittingSubpartitionsTest, IndentationTwoPartitionsWithTrailer) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  verible::BasicFormatStyle style;  // default
  style.column_limit = 14 + 7;

  UnwrappedLine header(7, begin);
  header.SpanNextToken();

  UnwrappedLine arg1(7 + style.indentation_spaces, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine arg2(7 + style.indentation_spaces, arg1.TokensRange().end());
  arg2.SpanNextToken();
  UnwrappedLine arg3(7 + style.indentation_spaces, arg2.TokensRange().end());
  arg3.SpanNextToken();
  UnwrappedLine arg4(7 + style.indentation_spaces, arg3.TokensRange().end());
  arg4.SpanNextToken();

  UnwrappedLine args(7 + style.indentation_spaces, arg1.TokensRange().begin());
  args.SpanUpToToken(arg4.TokensRange().end());

  UnwrappedLine trailer(7, args.TokensRange().end());
  trailer.SpanNextToken();

  UnwrappedLine all(7, header.TokensRange().begin());
  all.SpanUpToToken(trailer.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
      },
      tree_type{trailer},
  };

  UnwrappedLine group1(0, header.TokensRange().begin());
  group1.SpanUpToToken(arg2.TokensRange().end());
  UnwrappedLine group2(0, arg3.TokensRange().begin());
  group2.SpanUpToToken(trailer.TokensRange().end());

  const tree_type tree_expected{
      all,
      tree_type{
          group1,
          tree_type{header},
          tree_type{arg1},
          tree_type{arg2},
      },
      tree_type{
          group2,
          tree_type{arg3},
          tree_type{arg4},
          tree_type{trailer},
      },
  };

  auto saved_tree(tree);
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check group nodes indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 7);
  EXPECT_EQ(tree.Children()[1].Value().IndentationSpaces(),
            header.TokensRange()[0].Length() + 7);  // appended

  EXPECT_EQ(saved_tree.Children()[0].Value().IndentationSpaces(),
            tree.Children()[0].Children()[0].Value().IndentationSpaces());
  EXPECT_EQ(tree.Children()[0].Children()[1].Value().IndentationSpaces(), 7);
  EXPECT_EQ(tree.Children()[0].Children()[2].Value().IndentationSpaces(), 7);

  EXPECT_EQ(tree.Children()[1].Children()[0].Value().IndentationSpaces(),
            header.TokensRange()[0].Length() + 7);  // appended
  EXPECT_EQ(tree.Children()[1].Children()[1].Value().IndentationSpaces(),
            header.TokensRange()[0].Length() + 7);  // appended
  EXPECT_EQ(tree.Children()[1].Children()[2].Value().IndentationSpaces(),
            header.TokensRange()[0].Length() + 7);  // appended
}

// One subpartition per line
TEST_F(ReshapeFittingSubpartitionsTest, OnePerLine) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  verible::BasicFormatStyle style;  // default

  const int kIndent = style.indentation_spaces;

  UnwrappedLine header(1 * kIndent, begin);
  header.SpanNextToken();

  UnwrappedLine arg1(2 * kIndent, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine arg2(2 * kIndent, arg1.TokensRange().end());
  arg2.SpanNextToken();
  UnwrappedLine arg3(2 * kIndent, arg2.TokensRange().end());
  arg3.SpanNextToken();
  UnwrappedLine arg4(2 * kIndent, arg3.TokensRange().end());
  arg4.SpanNextToken();

  UnwrappedLine args(2 * kIndent, arg1.TokensRange().begin(),
                     PartitionPolicyEnum::kAlwaysExpand);
  args.SpanUpToToken(arg4.TokensRange().end());

  UnwrappedLine all(1 * kIndent, header.TokensRange().begin());
  all.SpanUpToToken(args.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
      },
  };

  UnwrappedLine first_line(1 * kIndent, header.TokensRange().begin());
  first_line.SpanUpToToken(arg1.TokensRange().end());

  const tree_type tree_expected{
      all,
      tree_type{
          first_line,
          tree_type{header},
          tree_type{arg1},
      },
      tree_type{arg2, tree_type{arg2}},
      tree_type{arg3, tree_type{arg3}},
      tree_type{arg4, tree_type{arg4}},
  };

  auto saved_tree(tree);
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check group nodes indentation
  const int header_width = header.TokensRange()[0].Length();

  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 1 * kIndent);
  EXPECT_EQ(tree.Children()[0].Children()[0].Value().IndentationSpaces(),
            1 * kIndent);
  EXPECT_EQ(tree.Children()[0].Children()[1].Value().IndentationSpaces(),
            1 * kIndent);

  EXPECT_EQ(tree.Children()[1].Value().IndentationSpaces(),
            1 * kIndent + header_width);
  EXPECT_EQ(tree.Children()[1].Children()[0].Value().IndentationSpaces(),
            1 * kIndent + header_width);

  EXPECT_EQ(tree.Children()[2].Value().IndentationSpaces(),
            1 * kIndent + header_width);
  EXPECT_EQ(tree.Children()[2].Children()[0].Value().IndentationSpaces(),
            1 * kIndent + header_width);

  EXPECT_EQ(tree.Children()[3].Value().IndentationSpaces(),
            1 * kIndent + header_width);
  EXPECT_EQ(tree.Children()[3].Children()[0].Value().IndentationSpaces(),
            1 * kIndent + header_width);
}

// One subpartition per line
TEST_F(ReshapeFittingSubpartitionsTest, OnePerLineWithTrailer) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  verible::BasicFormatStyle style;  // default

  const int kIndent = style.indentation_spaces;

  UnwrappedLine header(1 * kIndent, begin);
  header.SpanNextToken();

  UnwrappedLine arg1(2 * kIndent, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine arg2(2 * kIndent, arg1.TokensRange().end());
  arg2.SpanNextToken();
  UnwrappedLine arg3(2 * kIndent, arg2.TokensRange().end());
  arg3.SpanNextToken();
  UnwrappedLine arg4(2 * kIndent, arg3.TokensRange().end());
  arg4.SpanNextToken();

  UnwrappedLine args(2 * kIndent, arg1.TokensRange().begin(),
                     PartitionPolicyEnum::kAlwaysExpand);
  args.SpanUpToToken(arg4.TokensRange().end());

  UnwrappedLine trailer(1 * kIndent, args.TokensRange().end());
  trailer.SpanNextToken();

  UnwrappedLine all(1 * kIndent, header.TokensRange().begin());
  all.SpanUpToToken(trailer.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
      },
      tree_type{trailer},
  };

  UnwrappedLine first_line(1 * kIndent, header.TokensRange().begin());
  first_line.SpanUpToToken(arg1.TokensRange().end());
  UnwrappedLine last_line(1 * kIndent, arg4.TokensRange().begin());
  last_line.SpanUpToToken(trailer.TokensRange().end());

  const tree_type tree_expected{
      all,
      tree_type{
          first_line,
          tree_type{header},
          tree_type{arg1},
      },
      tree_type{arg2, tree_type{arg2}},
      tree_type{arg3, tree_type{arg3}},
      tree_type{
          last_line,
          tree_type{arg4},
          tree_type{trailer},
      },
  };

  auto saved_tree(tree);
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check group nodes indentation
  const int header_width = header.TokensRange()[0].Length();

  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 1 * kIndent);
  EXPECT_EQ(tree.Children()[0].Children()[0].Value().IndentationSpaces(),
            1 * kIndent);
  EXPECT_EQ(tree.Children()[0].Children()[1].Value().IndentationSpaces(),
            1 * kIndent);

  EXPECT_EQ(tree.Children()[1].Value().IndentationSpaces(),
            1 * kIndent + header_width);
  EXPECT_EQ(tree.Children()[1].Children()[0].Value().IndentationSpaces(),
            1 * kIndent + header_width);

  EXPECT_EQ(tree.Children()[2].Value().IndentationSpaces(),
            1 * kIndent + header_width);
  EXPECT_EQ(tree.Children()[2].Children()[0].Value().IndentationSpaces(),
            1 * kIndent + header_width);

  EXPECT_EQ(tree.Children()[3].Value().IndentationSpaces(),
            1 * kIndent + header_width);
  EXPECT_EQ(tree.Children()[3].Children()[0].Value().IndentationSpaces(),
            1 * kIndent + header_width);
  EXPECT_EQ(tree.Children()[3].Children()[1].Value().IndentationSpaces(),
            1 * kIndent + header_width);
}

TEST_F(ReshapeFittingSubpartitionsTest, AvoidExceedingColumnLimit) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  verible::BasicFormatStyle style;  // default
  style.column_limit = 9;

  UnwrappedLine header(0, begin);
  header.SpanNextToken();

  UnwrappedLine arg1(1, header.TokensRange().end());
  arg1.SpanNextToken();
  UnwrappedLine arg2(1, arg1.TokensRange().end());
  arg2.SpanNextToken();
  UnwrappedLine arg3(1, arg2.TokensRange().end());
  arg3.SpanNextToken();
  UnwrappedLine arg4(1, arg3.TokensRange().end());
  arg4.SpanNextToken();

  UnwrappedLine args(1, arg1.TokensRange().begin());
  args.SpanUpToToken(arg4.TokensRange().end());

  UnwrappedLine trailer(0, args.TokensRange().end());
  trailer.SpanNextToken();

  UnwrappedLine all(0, header.TokensRange().begin());
  all.SpanUpToToken(trailer.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
      },
      tree_type{trailer},
  };

  UnwrappedLine second_line(1, arg1.TokensRange().begin());
  second_line.SpanUpToToken(arg2.TokensRange().end());
  UnwrappedLine third_line(1, arg3.TokensRange().begin());
  third_line.SpanUpToToken(arg4.TokensRange().end());

  const tree_type tree_expected{
      all,
      tree_type{header, tree_type{header}},
      tree_type{
          second_line,
          tree_type{arg1},
          tree_type{arg2},
      },
      tree_type{
          third_line,
          tree_type{arg3},
          tree_type{arg4},
      },
      tree_type{trailer, tree_type{trailer}},
  };

  auto saved_tree(tree);
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check group nodes indentation
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
  EXPECT_EQ(tree.Children()[0].Children()[0].Value().IndentationSpaces(), 0);

  EXPECT_EQ(tree.Children()[1].Value().IndentationSpaces(), 1);
  EXPECT_EQ(tree.Children()[1].Children()[0].Value().IndentationSpaces(), 1);
  EXPECT_EQ(tree.Children()[1].Children()[1].Value().IndentationSpaces(), 1);

  EXPECT_EQ(tree.Children()[2].Value().IndentationSpaces(), 1);
  EXPECT_EQ(tree.Children()[2].Children()[0].Value().IndentationSpaces(), 1);
  EXPECT_EQ(tree.Children()[2].Children()[1].Value().IndentationSpaces(), 1);

  EXPECT_EQ(tree.Children()[3].Value().IndentationSpaces(), 0);
  EXPECT_EQ(tree.Children()[3].Children()[0].Value().IndentationSpaces(), 0);
}

// Tests with real-world example
class ReshapeFittingSubpartitionsTestFixture
    : public ::testing::Test,
      public UnwrappedLineMemoryHandler {
 public:
  ReshapeFittingSubpartitionsTestFixture()
      // combining what would normally be a type and a variable name
      // into a single string for testing convenience
      : sample_(
            "function_fffffffffff( "
            "type_a_aaaa, type_b_bbbbb, "
            "type_c_cccccc, type_d_dddddddd, "
            "type_e_eeeeeeee, type_f_ffff);"),
        tokens_(absl::StrSplit(sample_, ' ')) {
    for (const auto token : tokens_) {
      ftokens_.emplace_back(TokenInfo{1, token});
    }
    CreateTokenInfos(ftokens_);
  }

 protected:
  const std::string sample_;
  const std::vector<absl::string_view> tokens_;
  std::vector<TokenInfo> ftokens_;
};

class ReshapeFittingSubpartitionsFunctionTest
    : public ReshapeFittingSubpartitionsTestFixture {};

TEST_F(ReshapeFittingSubpartitionsFunctionTest,
       FunctionWithSixArgumentsAndColumnLimit20Characters) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());

  // 'function_fffffffffff('
  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);

  // function arguments
  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanUpToToken(begin + 3);
  UnwrappedLine arg3(0, arg2.TokensRange().end());
  arg3.SpanUpToToken(begin + 4);
  UnwrappedLine arg4(0, arg3.TokensRange().end());
  arg4.SpanUpToToken(begin + 5);
  UnwrappedLine arg5(0, arg4.TokensRange().end());
  arg5.SpanUpToToken(begin + 6);
  UnwrappedLine arg6(0, arg5.TokensRange().end());
  arg6.SpanUpToToken(all.TokensRange().end());

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg6.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
          tree_type{arg6},
      },
  };

  verible::BasicFormatStyle style;
  style.column_limit = 20;

  ApplyPreOrder(tree.Children()[1], [&style](TokenPartitionTree& node) {
    auto& uwline = node.Value();
    uwline.SetIndentationSpaces(style.wrap_spaces);
  });

  // Expect each subpartition in its own partition...
  const tree_type tree_expected{
      all,
      tree_type{header, tree_type{header}},
      tree_type{arg1, tree_type{arg1}},
      tree_type{arg2, tree_type{arg2}},
      tree_type{arg3, tree_type{arg3}},
      tree_type{arg4, tree_type{arg4}},
      tree_type{arg5, tree_type{arg5}},
      tree_type{arg6, tree_type{arg6}},
  };

  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentations
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
  EXPECT_EQ(tree.Children()[1].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[2].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[3].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[4].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[5].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[6].Value().IndentationSpaces(), style.wrap_spaces);
}

TEST_F(ReshapeFittingSubpartitionsFunctionTest,
       FunctionWithSixArgumentsAndColumnLimit40Characters) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());

  // 'function_fffffffffff('
  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);

  // function arguments
  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanUpToToken(begin + 3);
  UnwrappedLine arg3(0, arg2.TokensRange().end());
  arg3.SpanUpToToken(begin + 4);
  UnwrappedLine arg4(0, arg3.TokensRange().end());
  arg4.SpanUpToToken(begin + 5);
  UnwrappedLine arg5(0, arg4.TokensRange().end());
  arg5.SpanUpToToken(begin + 6);
  UnwrappedLine arg6(0, arg5.TokensRange().end());
  arg6.SpanUpToToken(all.TokensRange().end());

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg6.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
          tree_type{arg6},
      },
  };

  verible::BasicFormatStyle style;
  style.column_limit = 40;

  ApplyPreOrder(tree.Children()[1], [&style](TokenPartitionTree& node) {
    auto& uwline = node.Value();
    uwline.SetIndentationSpaces(style.wrap_spaces);
  });

  UnwrappedLine group1(0, begin);
  group1.SpanUpToToken(header.TokensRange().end());
  UnwrappedLine group2(0, arg1.TokensRange().begin());
  group2.SpanUpToToken(arg2.TokensRange().end());
  UnwrappedLine group3(0, arg3.TokensRange().begin());
  group3.SpanUpToToken(arg4.TokensRange().end());
  UnwrappedLine group4(0, arg5.TokensRange().begin());
  group4.SpanUpToToken(arg6.TokensRange().end());

  const tree_type tree_expected{all,
                                tree_type{
                                    group1,
                                    tree_type{header},
                                },
                                tree_type{
                                    group2,
                                    tree_type{arg1},
                                    tree_type{arg2},
                                },
                                tree_type{
                                    group3,
                                    tree_type{arg3},
                                    tree_type{arg4},
                                },
                                tree_type{
                                    group4,
                                    tree_type{arg5},
                                    tree_type{arg6},
                                }};

  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentations
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
  EXPECT_EQ(tree.Children()[1].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[2].Value().IndentationSpaces(), style.wrap_spaces);
  EXPECT_EQ(tree.Children()[3].Value().IndentationSpaces(), style.wrap_spaces);
}

TEST_F(ReshapeFittingSubpartitionsFunctionTest,
       FunctionWithSixArgumentsAndColumnLimit56Characters) {
  const auto& preformat_tokens = pre_format_tokens_;
  const auto begin = preformat_tokens.begin();

  UnwrappedLine all(0, begin);
  all.SpanUpToToken(preformat_tokens.end());

  // 'function_fffffffffff('
  UnwrappedLine header(0, begin);
  header.SpanUpToToken(begin + 1);

  // function arguments
  UnwrappedLine arg1(0, header.TokensRange().end());
  arg1.SpanUpToToken(begin + 2);
  UnwrappedLine arg2(0, arg1.TokensRange().end());
  arg2.SpanUpToToken(begin + 3);
  UnwrappedLine arg3(0, arg2.TokensRange().end());
  arg3.SpanUpToToken(begin + 4);
  UnwrappedLine arg4(0, arg3.TokensRange().end());
  arg4.SpanUpToToken(begin + 5);
  UnwrappedLine arg5(0, arg4.TokensRange().end());
  arg5.SpanUpToToken(begin + 6);
  UnwrappedLine arg6(0, arg5.TokensRange().end());
  arg6.SpanUpToToken(all.TokensRange().end());

  UnwrappedLine args(0, arg1.TokensRange().begin());
  args.SpanUpToToken(arg6.TokensRange().end());

  using tree_type = TokenPartitionTree;
  tree_type tree{
      all,
      tree_type{header},
      tree_type{
          args,
          tree_type{arg1},
          tree_type{arg2},
          tree_type{arg3},
          tree_type{arg4},
          tree_type{arg5},
          tree_type{arg6},
      },
  };

  UnwrappedLine group1(0, begin);
  group1.SpanUpToToken(arg2.TokensRange().end());
  UnwrappedLine group2(0, arg3.TokensRange().begin());
  group2.SpanUpToToken(arg4.TokensRange().end());
  UnwrappedLine group3(0, arg5.TokensRange().begin());
  group3.SpanUpToToken(arg6.TokensRange().end());

  const tree_type tree_expected{all,
                                tree_type{
                                    group1,
                                    tree_type{header},
                                    tree_type{arg1},
                                    tree_type{arg2},
                                },
                                tree_type{
                                    group2,
                                    tree_type{arg3},
                                    tree_type{arg4},
                                },
                                tree_type{
                                    group3,
                                    tree_type{arg5},
                                    tree_type{arg6},
                                }};

  verible::BasicFormatStyle style;
  style.column_limit = 56;
  ReshapeFittingSubpartitions(style, &tree);

  const auto diff = DeepEqual(tree, tree_expected, TokenRangeEqual);
  EXPECT_EQ(diff.left, nullptr) << "Expected:\n"
                                << tree_expected << "\nGot:" << tree << "\n";

  // Check indentations (appending)
  EXPECT_EQ(tree.Children()[0].Value().IndentationSpaces(), 0);
  EXPECT_EQ(tree.Children()[1].Value().IndentationSpaces(),
            header.TokensRange()[0].Length());
  EXPECT_EQ(tree.Children()[2].Value().IndentationSpaces(),
            header.TokensRange()[0].Length());
}

class ApplyAlreadyFormattedPartitionPropertiesToTokensTest
    : public TokenPartitionTreeTestFixture {};

TEST_F(ApplyAlreadyFormattedPartitionPropertiesToTokensTest, EmptyTokenRange) {
  using TPT = TokenPartitionTreeBuilder;
  using SO = SpacingOptions;

  auto tree = TPT(3, {0, 0}, PartitionPolicyEnum::kAlreadyFormatted)
                  .build(pre_format_tokens_);

  ApplyAlreadyFormattedPartitionPropertiesToTokens(&tree, &pre_format_tokens_);

  static const int expected_spaces[] = {0, 0, 0, 0, 0, 0};
  static const SpacingOptions expected_decision[] = {
      SO::Undecided, SO::Undecided, SO::Undecided,
      SO::Undecided, SO::Undecided, SO::Undecided,
  };
  for (int i = 0; i < static_cast<int>(pre_format_tokens_.size()); ++i) {
    const auto& token = pre_format_tokens_.at(i);
    EXPECT_EQ(token.before.spaces_required, expected_spaces[i])
        << "Token " << i;
    EXPECT_EQ(token.before.break_decision, expected_decision[i])
        << "Token " << i;
  }
}

TEST_F(ApplyAlreadyFormattedPartitionPropertiesToTokensTest, NoInlines) {
  using TPT = TokenPartitionTreeBuilder;
  using SO = SpacingOptions;

  auto tree = TPT(1, {0, 5}, PartitionPolicyEnum::kAlreadyFormatted)
                  .build(pre_format_tokens_);

  ApplyAlreadyFormattedPartitionPropertiesToTokens(&tree, &pre_format_tokens_);

  static const int expected_spaces[] = {0, 0, 0, 0, 0, 0};
  static const SpacingOptions expected_decision[] = {
      SO::MustWrap,   SO::MustAppend, SO::MustAppend,
      SO::MustAppend, SO::MustAppend, SO::Undecided,
  };
  for (int i = 0; i < static_cast<int>(pre_format_tokens_.size()); ++i) {
    const auto& token = pre_format_tokens_.at(i);
    EXPECT_EQ(token.before.spaces_required, expected_spaces[i])
        << "Token " << i;
    EXPECT_EQ(token.before.break_decision, expected_decision[i])
        << "Token " << i;
  }
}

TEST_F(ApplyAlreadyFormattedPartitionPropertiesToTokensTest, TwoInlines) {
  using TPT = TokenPartitionTreeBuilder;
  using SO = SpacingOptions;

  auto tree = TPT(7, PartitionPolicyEnum::kAlreadyFormatted,
                  {
                      TPT(2, {0, 2}, PartitionPolicyEnum::kInline),
                      TPT(4, {2, 5}, PartitionPolicyEnum::kInline),
                  })
                  .build(pre_format_tokens_);

  ApplyAlreadyFormattedPartitionPropertiesToTokens(&tree, &pre_format_tokens_);

  static const int expected_spaces[] = {2, 0, 4, 0, 0, 0};
  static const SpacingOptions expected_decision[] = {
      SO::AppendAligned, SO::MustAppend, SO::AppendAligned,
      SO::MustAppend,    SO::MustAppend, SO::Undecided,
  };
  for (int i = 0; i < static_cast<int>(pre_format_tokens_.size()); ++i) {
    const auto& token = pre_format_tokens_.at(i);
    EXPECT_EQ(token.before.spaces_required, expected_spaces[i])
        << "Token " << i;
    EXPECT_EQ(token.before.break_decision, expected_decision[i])
        << "Token " << i;
  }
}

class TokenPartitionTreesEqualPredFormatTest
    : public TokenPartitionTreeTestFixture {};

TEST_F(TokenPartitionTreesEqualPredFormatTest, EqualityCheck) {
  using TPT = TokenPartitionTreeBuilder;

  static const auto ref_tree =
      TPT(PartitionPolicyEnum::kAlwaysExpand,
          {
              TPT(2, {0, 2}, PartitionPolicyEnum::kFitOnLineElseExpand),
              TPT(4, {2, 4}, PartitionPolicyEnum::kUninitialized),
          })
          .build(pre_format_tokens_);

  {
    static const auto tree = ref_tree;
    const auto result =
        TokenPartitionTreesEqualPredFormat("first", "second", ref_tree, tree);
    EXPECT_TRUE(result);
    EXPECT_STREQ(result.message(), "");
  }

  {
    // Different indentation of the first child
    static const auto tree =
        TPT(PartitionPolicyEnum::kAlwaysExpand,
            {
                TPT(3, {0, 2}, PartitionPolicyEnum::kFitOnLineElseExpand),
                TPT(4, {2, 4}, PartitionPolicyEnum::kUninitialized),
            })
            .build(pre_format_tokens_);
    const auto result =
        TokenPartitionTreesEqualPredFormat("first", "second", ref_tree, tree);
    EXPECT_FALSE(result);
    EXPECT_STREQ(result.message(),
                 "Expected equality of these trees:\n"
                 "Actual:\n"
                 "{ ([one two three four], policy: always-expand)\n"
                 "  { (>>[one two], policy: fit-else-expand) }\n"
                 "  { (>>>>[three four], policy: uninitialized) }\n"
                 "}\n"
                 "Expected:\n"
                 "{ ([one two three four], policy: always-expand)\n"
                 "  { (>>>[one two], policy: fit-else-expand) }\n"
                 "  { (>>>>[three four], policy: uninitialized) }\n"
                 "}\n");
  }
  {
    // Different tokens range
    static const auto tree =
        TPT(PartitionPolicyEnum::kAlwaysExpand,
            {
                TPT(2, {0, 2}, PartitionPolicyEnum::kFitOnLineElseExpand),
                TPT(4, {2, 5}, PartitionPolicyEnum::kUninitialized),
            })
            .build(pre_format_tokens_);
    const auto result =
        TokenPartitionTreesEqualPredFormat("first", "second", ref_tree, tree);
    EXPECT_FALSE(result);
    EXPECT_STREQ(result.message(),
                 "Expected equality of these trees:\n"
                 "Actual:\n"
                 "{ ([one two three four], policy: always-expand)\n"
                 "  { (>>[one two], policy: fit-else-expand) }\n"
                 "  { (>>>>[three four], policy: uninitialized) }\n"
                 "}\n"
                 "Expected:\n"
                 "{ ([one two three four five], policy: always-expand)\n"
                 "  { (>>[one two], policy: fit-else-expand) }\n"
                 "  { (>>>>[three four five], policy: uninitialized) }\n"
                 "}\n");
  }
  {
    // Different policy
    static const auto tree =
        TPT(PartitionPolicyEnum::kFitOnLineElseExpand,
            {
                TPT(2, {0, 2}, PartitionPolicyEnum::kFitOnLineElseExpand),
                TPT(4, {2, 4}, PartitionPolicyEnum::kUninitialized),
            })
            .build(pre_format_tokens_);
    const auto result =
        TokenPartitionTreesEqualPredFormat("first", "second", ref_tree, tree);
    EXPECT_FALSE(result);
    EXPECT_STREQ(result.message(),
                 "Expected equality of these trees:\n"
                 "Actual:\n"
                 "{ ([one two three four], policy: always-expand)\n"
                 "  { (>>[one two], policy: fit-else-expand) }\n"
                 "  { (>>>>[three four], policy: uninitialized) }\n"
                 "}\n"
                 "Expected:\n"
                 "{ ([one two three four], policy: fit-else-expand)\n"
                 "  { (>>[one two], policy: fit-else-expand) }\n"
                 "  { (>>>>[three four], policy: uninitialized) }\n"
                 "}\n");
  }
}

}  // namespace
}  // namespace verible