CodeQL 2.27.4 reports a syntax error for a valid call to a function named using when it is awaited. Found by checking extraction diagnostics in link-foundation/link-cli#166.

Minimal ECMAScript module:

async function using(store, action) { return action(store); }
await using({}, async () => {});

node --input-type=module < repro.mjs succeeds (Node 24 locally; Node 26, Bun and Deno accepted the original downstream conformance suite). CodeQL JavaScript extraction reports Syntax error: unexpected token '(' at the call, and SARIF includes js/syntax-error despite an empty results array and successful invocation. Real failing run: https://github.com/link-foundation/link-cli/actions/runs/42130454613 (CodeQL javascript-typescript).

The apparent parser cause is javascript/extractor/src/com/semmle/js/parser/Parser.java: isAwaitUsing() checks only the words await using, and parseStatement() then selects parseVarStatement(..., "using") without requiring a following binding identifier. This misclassifies the call as an await-using declaration. isUsingDecl() already has binding lookahead for unawaited using.

Expected: parse the expression statement as an awaited function call. Suggested fix: require valid declaration binding lookahead after await using before choosing the declaration production; retain actual await using resource = expression parsing. Add both forms as parser regression fixtures.

Workaround: rename the helper (downstream uses withClient) while keeping all conformance scenarios. Reproducer and collected SARIF: https://github.com/link-foundation/link-cli/tree/issue-165-a5206aa5b4c0/dev/log/issues/165/pulls/166 . The standalone reproducer is experiments/issue-165/codeql-using-repro.mjs.txt (text suffix prevents the known parser defect from breaking its own audit).