formatter: Preserve operator spacing in ternary expressions inside subscript brackets

`InRangeLikeContext()` previously matched all tokens nested inside subscript
dimension nodes (`kDimensionScalar`), causing compact indexing rules to strip spaces
around operators even within ternary condition expressions (`kConditionExpression`).

This produced invalid syntax like `some_array[b>1'h0?1'h0 : c]`.

Exclude `kConditionExpression` in `InRangeLikeContext()` so operators inside
ternary expressions within subscript brackets retain normal spacing rules.

Verified #2597 with new test case
`FormatterEndToEndTest.TernaryInsideSubscriptExpression`

Fixes #2597

.bazelrc

diff --git a/.bazelrc b/.bazelrc
index 301b564..dc2e33d 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -1,6 +1,8 @@
 # bazel < 7 needs explicit enabling of bzlmod dependencies.
 build --enable_bzlmod
 
+test --test_output=errors
+
 # Enable support for absl types like string_view in gtest.
 build --define="absl=1"
 

verible/verilog/formatting/formatter_module_test.cc

diff --git a/verible/verilog/formatting/formatter_module_test.cc b/verible/verilog/formatting/formatter_module_test.cc
index f6e142b..c61da86 100644
--- a/verible/verilog/formatting/formatter_module_test.cc
+++ b/verible/verilog/formatting/formatter_module_test.cc
@@ -3050,6 +3050,40 @@
   RunFormatterTestCases40(kModuleFormatterTestCases);
 }
 
+TEST(FormatterEndToEndTest, TernaryInsideSubscriptExpression_issue2597) {
+  static constexpr FormatterTestCase kTestCases[] = {
+      // Outside subscript
+      {"module foo ();\n"
+       "assign a = b > 1'h0 ? 1'h0 : c;\n"
+       "endmodule\n",
+
+       "module foo ();\n"
+       "  assign a = b > 1'h0 ? 1'h0 : c;\n"
+       "endmodule\n"},
+
+      // Inside subscript.
+      {"module foo ();\n"
+       "assign a = some_array[b > 1'h0 ? 1'h0 : c];\n"
+       "endmodule\n",
+
+       "module foo ();\n"
+       "  assign a = some_array[b > 1'h0 ? 1'h0 : c];\n"
+       "endmodule\n"},
+  };
+
+  FormatStyle style;
+  style.indentation_spaces = 2;
+  for (const auto &test_case : kTestCases) {
+    VLOG(1) << "code-to-format:\n" << test_case.input << "<EOF>";
+    std::ostringstream stream;
+    const auto status =
+        FormatVerilog(test_case.input, "<filename>", style, stream);
+    // Require these test cases to be valid.
+    EXPECT_OK(status) << status.message();
+    EXPECT_EQ(stream.str(), test_case.expected) << "code:\n" << test_case.input;
+  }
+}
+
 }  // namespace
 }  // namespace formatter
 }  // namespace verilog

verible/verilog/formatting/token-annotator.cc

diff --git a/verible/verilog/formatting/token-annotator.cc b/verible/verilog/formatting/token-annotator.cc
index fc6d2f0..959364e 100644
--- a/verible/verilog/formatting/token-annotator.cc
+++ b/verible/verilog/formatting/token-annotator.cc
@@ -117,7 +117,7 @@
   return context.IsInsideFirst(
       {NodeEnum::kDimensionScalar, NodeEnum::kDimensionRange,
        NodeEnum::kDimensionSlice, NodeEnum::kCycleDelayRange},
-      {});
+      {NodeEnum::kConditionExpression});  // exclude
 }
 
 static bool IsAnySemicolon(const PreFormatToken &ftoken) {

verible/verilog/formatting/token-annotator_test.cc

diff --git a/verible/verilog/formatting/token-annotator_test.cc b/verible/verilog/formatting/token-annotator_test.cc
index 2adf936..0bd6485 100644
--- a/verible/verilog/formatting/token-annotator_test.cc
+++ b/verible/verilog/formatting/token-annotator_test.cc
@@ -5501,6 +5501,31 @@
           {NodeEnum::kUnpackedDimensions},
           {1, SpacingOptions::kPreserve},
       },
+      {
+          // [b > 1'h0 ? 1'h0 : c] : space around '>' in ternary inside
+          // subscript
+          DefaultStyle,
+          verilog_tokentype::SymbolIdentifier,
+          "b",
+          " ",  // 1 space originally
+          '>',
+          ">",
+          {NodeEnum::kDimensionScalar, NodeEnum::kConditionExpression},
+          {NodeEnum::kDimensionScalar, NodeEnum::kConditionExpression},
+          {1, SpacingOptions::kUndecided},
+      },
+      {
+          // [b > 1 ? 1 : c] : space before '?' in ternary inside subscript
+          DefaultStyle,
+          verilog_tokentype::TK_DecNumber,
+          "1",
+          " ",  // 1 space originally
+          '?',
+          "?",
+          {NodeEnum::kDimensionScalar, NodeEnum::kConditionExpression},
+          {NodeEnum::kDimensionScalar, NodeEnum::kConditionExpression},
+          {1, SpacingOptions::kUndecided},
+      },
   };
   int test_index = 0;
   for (const auto &test_case : kTestCases) {