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Malte UblandClaude Opus 5.5
daf4ff6a2b
`scriptc coverage` now lists every WebAssembly module whose bytes the build can see, with its size, whether it validates, its function, import and export counts, and the WebAssembly proposals it uses. Nothing is translated yet; builds are unchanged. - packages/compiler/src/wasm/binary.ts decodes and validates a module in plain TypeScript (the native compiler compiles it too) at the feature level scriptc means to translate: the MVP plus sign-extension, non-trapping float-to-int, bulk memory, multi-value, mutable globals, reference types and extended constant expressions. Where WebAssembly 3.0 and V8 relaxed a 2.0 rule (global initializers reading defined globals, memory indices), it follows V8, the behavior oracle. Modules that use SIMD, threads, exception handling, tail calls, function references or GC, memory64 or multiple memories still decode, and are reported as needing that proposal instead of as invalid. - packages/compiler/src/wasm/discover.ts finds modules from four sources: paths the compiler resolves from the source text (require.resolve, createRequire(...).resolve, import.meta.resolve, new URL(..., import.meta.url), __dirname joins), inline base64 and byte-array literals, the .wasm files of reached packages whose code mentions WebAssembly, and a `scriptc.wasm` list in package.json or the new coverage-only `--wasm <file>` flag. Modules are reported once, by SHA-256, with every source that found them; module files are input probes of the coverage verdict cache. The JSON envelope (--print=diagnostics) carries the same records under `wasmModules`. Evidence: packages/compiler/test/wasm-spec.test.ts runs the decoder over the 3,017 distinct binary modules of the WebAssembly 2.0 core test suite (without SIMD) and the extended-const proposal's tests, generated by gen-wasm-spec-cases.mjs with wabt's wast2json, and requires V8's verdict for each; 8,000 seeded mutations of those modules must also agree with V8, as must undici's inline llhttp modules (scalar valid, SIMD reported) and es-module-lexer's. src/wasm/binary.test.ts checks each feature and each error class against V8. On the survey's real modules the decoder agrees with V8 for quickjs-wasi (637 KB, 36 ms) and photon (1.9 MB, 121 ms). tests/coverage-fixtures/wasm pins the four discovery sources. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>