Phase 4 of the CJS↔SDK hard-seam migration (parent #3524).
Eliminates the `findProjectRoot` duplication that lived at
bin/lib/core.cjs:74-140 and sdk/src/query/helpers.ts:497-590,
the drift carrier behind historical bugs #1362 and #2561.
- sdk/src/project-root/index.ts — source of truth (120 lines,
pure-with-sync-fs). Exports findProjectRoot(startDir: string)
and FIND_PROJECT_ROOT_MAX_DEPTH constant.
- sdk/src/project-root/index.test.ts — 13 vitest pinning fixtures
covering all four heuristics, the #1362 guard, malformed
config fallback, empty sub_repos, deep nesting, and depth-limit
enforcement.
- sdk/scripts/gen-project-root.mjs — generator. Captures
function body via Function.prototype.toString() from compiled
sdk/dist/. Emits CJS preamble for destructured node:fs /
node:path / node:os imports.
- sdk/scripts/check-project-root-fresh.mjs — freshness check.
Imports the generator function directly (Phase 3's cleaner
pattern).
- get-shit-done/bin/lib/project-root.generated.cjs — generator-
emitted CJS mirror.
- tests/project-root-generator.test.cjs — 11 parity assertions
comparing SDK source and generated CJS for every fixture.
- sdk/src/query/helpers.ts: -127 lines. The 94-line inline
findProjectRoot plus the FIND_PROJECT_ROOT_MAX_DEPTH constant
(originally at line 471) replaced by a single re-export:
`export { findProjectRoot } from '../project-root/index.js';`
Removed unused `parse as parsePath` import.
- get-shit-done/bin/lib/core.cjs: -83 lines net. The 67-line
inline findProjectRoot replaced by a single
`require('./project-root.generated.cjs')`. The detectSubRepos
helper at lines 40-56 stays (used by loadConfig migration).
- sdk/package.json: gen:project-root + check:project-root-fresh
scripts.
- package.json: proxy for the freshness check.
- .githooks/pre-commit: drift block.
- .github/workflows/test.yml: drift check step after the
state-document drift step.
- CONTEXT.md: Project-Root Resolution Module entry.
- docs/INVENTORY.md, docs/INVENTORY-MANIFEST.json:
+1 module count, +1 row.
- Full suite: 9226/9226 pass (baseline 9215 + 11 new parity
fixtures).
- SDK vitest: 1804/1804 pass.
- Reader shrink: -127 SDK + -83 CJS = 210 lines of duplication
deleted across the two Readers. New shared Module is 120 lines.
1. Depth limit canonicalization. CJS findProjectRoot previously
had no explicit walk-up bound (walked until dir === root or
homedir). The new Module uses FIND_PROJECT_ROOT_MAX_DEPTH = 10,
matching the SDK's pre-existing value. Only affects paths
nested more than 10 levels deep from a .planning/ root — a
pathological case in practice. None of the existing 22 CJS
findProjectRoot tests covered this; the new parity test does.
2. platformReadSync → readFileSync. The old CJS findProjectRoot
used the platformReadSync wrapper from
shell-command-projection.cjs for reading .planning/config.json,
which returns null on read failure. The Module uses raw
readFileSync, which throws — caught by the surrounding
try/catch that already swallowed errors. Functionally
equivalent for the existing code path; no test exercises the
null-return semantic.
Closes#3553.