## What & why
Swept the repo for hand-rolled regex/string parsers that reimplement a
solved problem, and replaced the genuinely fragile ones with
battle-tested packages (or deps already in the tree). Each swap is
paired with a regression test for an input the old code got wrong.
| Site | Was | Now |
|------|-----|-----|
| `adb.ts` `resolveAvdPath`, `linux-preflight.ts` `readMb` | per-key
anchored regex over AVD `.ini` / `config.ini` | **`ini`** |
| `workspace-reader.ts` `extractEnvKeys` | split-on-first-`=` line loop
| **`dotenv`** (`parse`) |
| `uninstall.ts` `readBundledSkillName` | `^name:(.+)$` capture +
outer-quote strip | **`yaml`** (already a dep) |
| `mcp-configs.ts` `escapeRegExp` | hand-rolled char-class escape |
**`escape-string-regexp`** |
| `export.ts` xctrace version, `session-context.ts` RN minor |
`match(/(\d+)\./)` / `split(".")[1]` | **`semver`** `coerce` (already a
dep) |
| `source-resolver.ts` `parseDebugStack` | `at fn (file:l:c)` regex
(required both line+col) | **`stacktrace-parser`** |
### Bugs these fix (covered by new tests)
- **ini**: a quoted `path = "/Users/My Name/.../X.avd"` kept its quotes,
failed the `startsWith("/")` guard → AVD unresolved. Inline comments /
trailing junk after a sizing value made the anchored regex return `null`
→ sizing warning silently lost.
- **dotenv**: `export FOO=bar` produced the key `"export FOO"` (dropped
by the identifier filter); a multi-line quoted value leaked its
continuation lines (`FAKE=...`) as phantom keys.
- **yaml**: a `name:` value with a trailing `# comment` was taken
verbatim (comment included); odd quoting only had one outer pair
stripped.
- **stacktrace-parser**: a `:line`-only frame (no column, as Hermes/JSC
can emit) became an unusable `unknown` frame.
## Deliberately left alone (not "flaky", or no safe swap)
To avoid churn and regressions, I did **not** touch:
- **`uiautomator-parser.ts`** hand-rolled XML parser — a deliberate,
documented choice with a dedicated hardening suite, including a
*leniency* test for malformed dumps (stray `</node>`). A spec XML parser
would reject inputs this is built to recover from.
- **`ios-profiler/pipeline/xml-parser.ts`** (xctrace XML) — the most
tangled parser, but it has no real `.trace` fixtures and only thin
entity-decode tests. A rewrite can't be proven equivalent without
device-generated traces, so swapping it blind risks silently breaking
iOS CPU/hang/leak reports. Best done separately with a captured fixture.
- **`http.ts` `extractHostname`** — DNS-rebinding guard; `URL.hostname`
keeps the IPv6 brackets the loopback check compares without, so the
"fix" isn't simpler and the path is security-sensitive.
- **`adb.ts` `shellQuote`** — the POSIX single-quote escape is the
standard correct form.
- **`parseAdbDevices`, `android-screen.ts` `wm size`, `detect-app.ts`
dumpsys** — tool-specific CLI-output scraping with no clean package
equivalent (and documented edge-case handling).
- **`workspace-reader.ts` `extractMetroPort`** — a best-effort heuristic
over JS config; a correct replacement needs an AST parse, out of scope
here.
- **`config-parse.ts` Yarn/npm age-gate parsing** — a precise,
unit-tested domain parser; `ms` would introduce a bare-number ambiguity.
## Verification
- `tsc --build` clean across the workspace graph.
- Tests: tool-server **1205**, installer **264**, update-core **31** —
all pass (incl. the new regression tests).
- `prettier --check` clean on all changed files.
- Production esbuild bundle (`bundle-tools.cjs`) emits a valid
`tool-server.cjs`/`mcp-server.mjs` with
`ini`/`dotenv`/`stacktrace-parser` inlined (`node --check` OK). *(The
script's final step errored only on the auth-gated
`trace-processor.wasm` download, unrelated to bundling.)*
New runtime deps: `ini`, `dotenv`, `stacktrace-parser` (tool-server),
`escape-string-regexp` (installer) — all small, pure-JS. Lockfile change
is purely additive.
## Summary
These tests were taking up too long.
| File | Before | After |
|------|-------:|------:|
| `fetch-timeout.test.ts` hanging-POST test | 6281ms | ~600ms |
| `workspace-reader.test.ts` (full file) | ~4500ms | ~140ms |
| `gather-workspace-data.test.ts > valid snapshot` | ~590ms | ~3ms |
**Package totals:** `packages/mcp` 6.44s → ~830ms,
`packages/tool-server` 5.29s → ~790ms.
### What was slow and why
- `fetchWithReconnect` is now exported from `mcp-server.ts` so the test
uses the real function. The config accepts an `expBackoffBase` and a
`fetchTimeoutMs` so the hanging-POST test shrinks the backoff base to
`5ms` and the per-attempt timeout to `100ms` (~575ms total)
- every `readWorkspaceSnapshot` call spawned 8 real subprocesses
(`node`, `npm`, `yarn`, `pnpm`, `bun`, `pod`, `eas`, `expo`) via
`runVersionCommand`. Added `vi.mock("node:child_process", ...)` that
stubs `execFile`.
* feat: add first implememntation of environment subagent
* chore: remove the irrelavnt skill from main project config
* feat: add rules support and enhance postinstall script for Argent tools (#23)
* feat: add first implememntation of environment subagent
* feat: enhance argent.md with environment inspection subagent details and workspace information retrieval guidelines
* feat: introduce argent.md with comprehensive guidelines for iOS simulator interactions and React Native workflows
* fix: fix postinstall script
* fix: fix Install Argent launch.json job
* feat: add environment inspector design document and research notes on MCP error signaling
* chore: update .gitignore to include MCP agents and rules directories
* fix: update `argent.md` rule with alwaysApply: true for cursor compatibility
* chore: remove mcp/rules from index
Ignacy Łątka