fix(sourcemap): crc32 is not a function on Node.js < 20.15 (CLI-34F)

[cursor]

Sentry issues: CLI-34F, CLI-34B (same crash, split into two groups)

Fixes CLI-34F
Fixes CLI-34B

Root cause

src/lib/sourcemap/zip.ts imports crc32 from node:zlib, but that API only exists on Node.js >= 20.15 / >= 22.2. The npm package accepts older runtimes (engines: >=20.0, and the bundle's version gate allows Node 18+).

Reproduction

On Node.js 20.0–20.14 (both reports are 20.11 / 20.12), run sentry sourcemap upload <dir>, typically through @sentry/bundler-plugins. The first ZipWriter.addEntry() throws:

TypeError: (0 , import_node_zlib.crc32) is not a function

I reproduced this on a real Node v20.11.1 by bundling zip.ts to CJS (the npm build's output format) and writing an archive with it.

Fix

New src/lib/crc32.ts exports a crc32 that uses zlib.crc32 when it exists and otherwise falls back to a table-driven implementation of the same IEEE 802.3 polynomial. The sourcemap ZipWriter now imports it instead of node:zlib's crc32. Supported Node versions keep the native implementation.

The same bundle on Node v20.11.1 now writes the archive, and unzip -t reports every entry's CRC as OK.

Tests

• test/lib/crc32.property.test.ts: the fallback matches zlib.crc32 on random bytes, continuing from a previous checksum matches hashing the concatenation, and the standard check value ("123456789" → 0xCBF43926) holds.
• test/lib/sourcemap/zip.mocked.test.ts: mocks node:zlib without crc32 and checks that ZipWriter output passes unzip -t. Without the fix it fails with TypeError: crc32 is not a function.
• vitest run test/lib test/commands test/types test/script: 9988 passed, 1 failed. The failure is delta-upgrade.mocked.test.ts, which also fails on origin/main in this environment and is unrelated.
• biome check and tsc --noEmit pass.

Not in this PR

src/lib/build/zip-writer.ts (sentry build upload) also imports zlib.crc32 and has the same latent problem on these Node versions. There are no Sentry reports for that path yet, so it's left for a follow-up that switches it to this helper once this lands.

  

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Project	Deployment	Actions	Updated
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