Bug Report

getLeadingCommentRanges misses comments that are in front of arguments passed to a call expression.

Comments being missed is a known issue when comments are within a node between tokens not stored in the tree: https://github.com/Microsoft/TypeScript/wiki/FAQ#why-some-comments-are-not-preserved-in-emitted-javascript-even-when---removecomments-is-not-specified

However that is not the case here and in fact tsc will preserve that particular comment.

Note: here I refer to getLeadingCommentRanges but in reality the bug is present inside of iterateCommentRanges (what getLeadingCommentRanges uses under the hood)

🔎 Search Terms

• leading, trailing comment undefined
• getLeadingCommentRanges, getTrailingCommentRanges
• Call expression, function call, method call

🕗 Version & Regression Information

• This is the behavior in every version I tried (4.3.5 (the oldest version on ts-ast-viewer.com), 5.1.6, @next (5.2.0-dev.20230706))

⏯ Playground Link

https://ts-ast-viewer.com/#code/MYewdgziA2CmB00QHMAUB6AVAAgBa2iW03WwCIB3EAJ2gBMyBKIA

💻 Code

console.log(/* hello */ "world")

Calling getLeadingCommentRanges on the string literal returns undefined.

🙁 Actual behavior

ts.getLeadingCommentRanges('console.log(/* hello */ "world")', 12)

returns undefined

🙂 Expected behavior

ts.getLeadingCommentRanges('console.log(/* hello */ "world")', 12)

returns [ { kind: 3, start: 12, end: 23, hasTrailingNewLine: false } ]