deno

74caf3c7 - fix(repl): report descriptive syntax error instead of "Unexpected token '<'" (#35016)

fix(repl): report descriptive syntax error instead of "Unexpected token '<'" (#35016) ## Problem Malformed input that swc can recover from produces a misleading error. For example: ```ts const test = (i, 2 * i) => console.log(i); ``` Both in the REPL and when run from a `.ts` file, Deno reports: ``` error: Uncaught SyntaxError: Unexpected token '<' ``` even though there is no `<` anywhere in the source. ## Root cause swc's parser *recovers* from the malformed arrow parameters by inserting an `Invalid` placeholder node into the AST (emitting a non-fatal `SyntaxError: Not a pattern`, but still returning a successfully-parsed program). `swc_ecma_codegen` then emits each `Invalid` node as the literal text `<invalid>`, so the transpiled JavaScript contains a stray `<` that V8 rejects with `Unexpected token '<'`. `deno_ast`'s transpile only aborts on a hard-coded set of *fatal* syntax errors, which does not include the recoverable errors that leave `Invalid` nodes behind — so the broken output is emitted and executed. ## Fix Add `deno_resolver::emit::invalid_syntax_parse_diagnostics`, which returns the recovered-from parse diagnostics when the parsed program still contains an `Invalid` node (it fast-paths the common case of a well-formed source with no recovered diagnostics, so the AST is only walked when swc actually recovered from an error). It is wired into: - the module emit path (`libs/resolver/emit.rs`), covering `deno run`, `deno bundle`, `deno compile`, etc.; - the REPL (`cli/tools/repl/session.rs`). Because the REPL parses as `.tsx` first, it now falls back to a TypeScript parse when the `.tsx` parse only recovered with an `Invalid` node, so TypeScript type assertions like `<string>x` (which look like JSX in `.tsx`) keep working. This only ever newly-rejects code that already produced `<invalid>` output (which was never valid JavaScript), so it is not a behavior regression. After the fix: ``` $ deno run main.ts error: SyntaxError: Not a pattern | 1 | const test = (i, 2 * i) => console.log(i); | ~~~~~ at file:///.../main.ts:1:18 ``` ``` > const test = (i, 2 * i) => console.log(i); parse error: Not a pattern at 1:18 ``` ## Tests - `tests/specs/run/error_syntax_invalid_arrow_params` — `deno run` of the malformed file. - `tests/integration/repl_tests.rs`: - `syntax_error_invalid_arrow_params` — REPL regression test. - `type_assertion_still_parses` — guards the `.tsx` → TypeScript fallback so `<string>x` type assertions still evaluate. Closes #19457 Closes denoland/divybot#526 Co-authored-by: divybot <divybot@users.noreply.github.com> Co-authored-by: Divy Srivastava <me@littledivy.com>