coverage false positives for structural lines like } finally {

[DanTup]

A PR was raised at Dart-Code/Dart-Code#5769 to work around this issue in Dart-Code, but I think it would be better to resolve the problem in the source data here.

Original description from @tcf909:

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Description

This PR fixes false positive coverage reporting for structural lines like } finally { that are incorrectly shown as uncovered in VS Code's coverage visualization.

Problem

The Dart VM incorrectly generates branch coverage entries (BRDA) for structural lines like } finally { without corresponding line coverage entries (DA). This causes the extension to mark these lines as coverable but uncovered, resulting in:

• Red gutter markers on structural lines
• Coverage showing < 100% even when all executable code is covered

Example

try {
  // code
} finally {  // ← Line incorrectly shown as uncovered
  cleanup();
}

lcov.info data:

DA:227,1    (line before finally - covered)
BRDA:229,0,0,0  (} finally { - spurious entry!)
DA:230,1    (first line in finally - covered)

Related Issues

Similar to dart-lang/sdk#31222 which fixed async function closing brace coverage issues.

[DanTup]

cc @liamappelbe