Reduce npm lockfile parsing allocations - #95
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🟡 Changes recommended
An unresolved CRLF parsing bug can produce duplicate dependencies.
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Pull request overview
Reduces allocations in npm lockfile parsing while preserving parsing behavior, with added benchmarks and regression coverage.
Changes:
- Preallocates dependency results for v1 parsing.
- Uses iterator-based line parsing for v2/v3.
- Adds allocation benchmarks and edge-case tests.
File summaries
| File | Summary |
|---|---|
npm_bench_test.go |
Adds large-lockfile benchmarks. |
npm_allocation_test.go |
Adds allocation and parsing regression tests. |
internal/npm/npm.go |
Optimizes parsing; requires CRLF section termination handling to avoid duplicate dependencies. |
Review details
- Files reviewed: 3/3 changed files
- Comments generated: 1
- Review effort level: Lite
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Preallocate the dependency slice when parsing npm lockfiles and iterate v2/v3 lines without allocating a slice of every line. For lockfiles with 10,000 packages, this reduces allocated bytes by 41% for v1 and 45% for v3.
Also fix duplicate dependencies when parsing v2 lockfiles with CRLF line endings: stop at the end of
packagesinstead of continuing into the legacydependenciessection.