4 Commits

Author	SHA1	Message	Date
overlookmotel	ea2880170a	test(package/codegen): add benchmark with sourcemaps (#25772) ... Add benchmarks for source maps in `oxc-codegen`. 2 benchmarks: 1. Full end-to-end. 2. Without the actual sourcemap generation at the end. The 2nd is to measure the overhead that pushing to the sourcemap arrays adds while printing in isolation.	2026-08-18 16:17:46 +00:00
camc314	300763f328	feat(packages/codegen): add full source map support (#25585) ... ## Summary Align `oxc-codegen` source maps with Rust `oxc_codegen`, using the Rust implementation as the conformance oracle. This PR: - changes `printSync` to return `{ code, map? }`; - returns a standard Source Map v3 object; - exposes Rust’s generated source map through `codegen_conformance`; - compares the complete JS and Rust source maps; - supports Oxc `start`/`end` offsets and TS-ESTree `range` offsets; - uses `sourceText` to convert UTF-16 offsets and recover original identifier spellings; - validates both maps and no-maps builds in both `preserveParens` modes; - aligns mapping placement across JavaScript, TypeScript, JSX, templates, imports, destructuring, delimiters, and postfix chains; - handles astral characters and all ECMAScript line terminators. `loc`-only ASTs are not supported for source maps. ## API change ```ts const { code, map } = printSync(program, { sourcemap: true, sourceFileName: "input.js", sourceText, }); ``` `map` is a Source Map v3 object: ```ts interface SourceMap { version: 3; mappings: string; names: string[]; sources: string[]; sourcesContent?: string[]; } ``` ## Implementation Mapped writes collect only: - the generated UTF-16 offset; - the original source offset; - the optional original identifier name. After printing, the generator builds line tables for the generated output and `sourceText`, converts the offsets to line/column positions, suppresses duplicate source positions, and encodes the result as base64 VLQ. The no-maps builds continue to remove mapping-specific writes at build time. ## Validation flow ```mermaid flowchart TB fixture["Fixture<br/>filename + sourceText + parse options"] fixture --> rustParse fixture --> jsParse subgraph rust["Rust oracle"] direction TB rustParse["Parse with oxc_parser"] normalize["Normalize Rust-only AST information"] rustPrint["Print with oxc_codegen<br/>source maps enabled"] rustResult["Expected result<br/>{ code, map }"] rustParse --> normalize normalize --> rustPrint rustPrint --> rustResult end subgraph js["JavaScript candidate"] direction TB jsParse["Parse ESTree with oxc-parser<br/>start/end or range offsets"] plainPrint["Print with no-maps build"] plainResult["Actual code"] mappedPrint["Print with maps-enabled build"] deferred["Record generated offsets,<br/>source offsets, and names"] encode["Convert UTF-16 offsets to positions<br/>deduplicate and encode VLQ"] mappedResult["Actual result<br/>{ code, map }"] jsParse --> plainPrint plainPrint --> plainResult jsParse --> mappedPrint mappedPrint --> deferred deferred --> encode encode --> mappedResult end rustParse --> parseGate jsParse --> parseGate rustResult --> codeGate plainResult --> codeGate mappedResult --> codeGate rustResult --> mapGate mappedResult --> mapGate parseGate["Parse agreement<br/>Rust success requires no JS errors"] codeGate["Code equality<br/>both JS builds equal Rust"] mapGate["Source Map v3 equality<br/>mappings + names + sources + content"] parseGate --> pass["Fixture passes"] codeGate --> pass mapGate --> pass ``` Each fixture runs with both `preserveParens: false` and `preserveParens: true`. ## AST normalization Rust’s AST contains information that ESTree cannot represent. The Rust AST is normalized before printing so the comparison measures code generation rather than representation differences. This includes: - parenthesized function and arrow-expression flags; - `import "m"` versus `import {} from "m"`; - absent versus empty import-attribute clauses; - `assert` versus `with` attribute keywords; - the unavailable ESTree span for a complete `with` clause.	2026-08-18 11:41:34 +00:00
camc314	46d237c9a7	chore(codegen,parser,tasks): pin benchmark fixtures by sha (#25557) ... Pin the Codegen benchmark fixture to an immutable `benchmark-files` commit. This makes benchmark inputs reproducible and prevents `main` updates from silently changing results.	2026-08-12 15:56:52 +00:00
overlookmotel	a4478e960a	feat(codegen): add oxc-codegen package (#25488) ... Add `oxc-codegen` package - a printer written in TS. ### Features - Prints JS, JSX, TS, TSX. - Matches `oxc_codegen` exactly on all Test262, TypeScript, Acorn-JSX fixtures. - Very fast. ### Deficiencies - Pretty-printing only (no compact/minified output). - No support for printing comments. - Source map support is semi-there, but largely untested, and poor API (design doc has some ideas on how to improve it). ### This PR adds - The printer code. - Conformance testing infra. - Further tests for edge cases. - README. - Design doc - how it differs from `oxc_codegen` and why, what produces the perf. ### This PR doesn't add - Not integrated into CI or release pipeline. ### Notes This started as a slop port of `oxc_codegen`. I've iterated on that base, cleaned it up a lot, and at least skimmed through all of it. I think it's in fairly decent shape. The design doc is I think worth a read. It explains the rationale for the choices, in particular the "1 codebase, 4 builds" approach. I've put it in a new top-level directory called `packages`. It's not an app, so didn't seem to me to fit alongside `apps/oxlint` and `apps/oxfmt`. It's pure JS, so not like e.g. `napi/parser`. And it felt too heavyweight to put into `npm` dir. But maybe there's a better place for it. Co-authored-by: Cameron <cameron.clark@hey.com>	2026-08-12 13:41:31 +00:00