bun-runtime skill is outdated — predates the Bun 1.2–1.4 line (lockfile, test/PM CLI, built-in APIs)

[t-biju]

Summary

The bun-runtime skill (skills/bun-runtime/SKILL.md, ECC 2.2.1) reads as pre-1.2 Bun and does not reflect the current Bun 1.4 line (release notes). It has no version baseline, still hedges on the legacy binary lockfile, and omits most of the runtime, test-runner, and package-manager surface Bun has shipped since. On a project pinned to bun@1.4, the guidance is stale and in places misleading.

Concrete issues in the current skill

• No version anchor. The skill never states a Bun baseline, so a reader can't tell what era it targets. Recommend stating a minimum (e.g. "written against Bun 1.4").
• Legacy lockfile hedging — lines 22, 35, and 83 repeat "bun.lock or bun.lockb". Text bun.lock has been the default since Bun 1.2; bun.lockb is legacy/opt-out. A 1.4-era skill should present bun.lock as the lockfile and drop the binary hedging. Bun 1.4 also adds SHA-512 lockfile integrity for GitHub/tarball dependencies.
• Factual error — runtime internals. Line 21 states the runtime is "implemented in Zig". This is wrong as of Bun 1.4: Bun was rewritten from Zig to Rust, and 1.4 is the first production release of that Rust rewrite. The line should be corrected.
• Testing section is minimal (lines 52–56: only bun test / bun test --watch). Bun 1.4 added bun test --parallel, --isolate, --shard, --changed, and --timings — all worth covering, especially for CI.
• Package-manager / CLI gaps. Not mentioned anywhere: bun run --parallel / --filter, bun audit / bun audit fix, bun dedupe, bun prune, bun outdated, bun pm diff, bun pm licenses, the global virtual store / --linker=isolated (up to ~7× faster installs), and workspace catalogs (bun add --catalog / bun add --filter).
• Built-in APIs are barely covered. The Runtime API example (lines 69–79) shows only Bun.file and Bun.serve. Bun ships much more that this skill should at least point at:
  • Earlier in the 1.x line (1.2+): Bun.sql (Postgres), Bun.s3, Bun.redis, and Bun.serve route objects / the full-stack HTML dev server.
  • New in 1.4: Bun.Image, Bun.markdown, Bun.cron, Bun.Terminal, Bun.WebView, Bun.JSON5 / JSONC / JSONL / XML / Archive, native CompressionStream/DecompressionStream, HTTP/3 in Bun.serve() and fetch(), and a built-in React compiler.
• Overly cautious Node-compat framing (line 15 "Prefer Node for: maximum ecosystem compatibility"; line 26 "most packages work"). Bun 1.4's Node-compatibility push (node:http / node:fs / node:cluster now passing the large majority of Node's own test suite) makes this more conservative than current reality.

Suggested fix

Refresh skills/bun-runtime/SKILL.md against the Bun 1.4 release notes: state a version baseline, make bun.lock the single lockfile story, expand the testing and package-manager sections with the 1.4 CLI flags, and broaden the built-in-API list. Happy to send a PR if that's useful.

Ref: Bun 1.4 release notes — https://bun.com/blog/bun-v1.4
Environment: ECC 2.2.1; project pinned to bun@1.4.0.

_{Filed as a free-form issue (no structured form fits a docs-accuracy report; blank issues are enabled). Suggested triage labels: bug · area:docs · needs-triage.}