JavaScript Source Maps, can we do better?
summary
The JavaScript source map spec is effectively frozen at v3 (over 12 years old) and breaks for post‑mortem debugging because mappings are optional and bundles lack stable identity. The talk shows the VLQ/base64 encoding and explains why a debug ID plus a symbol server solves lookup across deployments. Three Sentry techniques are compared: backward scanning, caller/name guessing, and costly but accurate AST reconstruction (works but is heavy). A TC39 task force (t49) and a Bloomberg RFC aim to standardize fixes.
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chapters (10)
- 0:00Introduction and background
- 1:52What are Source Maps
- 5:24Source Map format deep dive
- 13:51Post-hoc debugging challenges
- 16:43Problems with Source Maps today
- 20:54Debug IDs as a solution
- 24:01New keyword error issue
- 29:20Reconstructing original names
- 32:31Conformance and standardization gaps
- 37:03Future of Source Maps
