fix(detect): decouple node script discovery from PM detection + mirror resolver PM chain

[kjanat]

Problem

A pnpm-workspace member directory (package.json with scripts, no local lockfile, no packageManager/devEngines) reported "No project detected", and runner run build fell through to a bogus bun build. Detection gated script extraction on a detected Node PM; the resolver was already smart enough — that asymmetry was the bug.

Fix

1. Decouple script discovery from PM detection — a package.json is the Node signal. Gating is now manifest-presence based, applied to the parallel extract_tasks. A manifest-less subdirectory lists ancestor scripts only when it provably sits inside a JS monorepo (workspace-root-aware, VCS-bounded), so an unrelated outer project's package.json is never silently adopted.
2. Mirror the resolver's PM chain in detection — packageManager → devEngines.packageManager → enclosing-workspace lockfile/manifest, so runner info / runner install from a member target the right tool. Corepack semantics preserved: a present-but-unparseable legacy packageManager still emits a warning and is not silently superseded by devEngines (detect_pm_from_manifest short-circuits to None on an unparseable spec — verified, regression test node::detect_pm_from_manifest_blocks_dev_engines_when_package_manager_unparseable).

Shared VCS-bounded ancestor walk extracted into a reusable generic files::find_in_ancestors.

Commits

• fix(detect): decouple node script discovery from PM detection
• fix(detect): mirror resolver PM chain (devEngines + workspace-upward)
• changelog: record go.mod task name + node-detection fixes

Base: master. Rebased onto current master (post-#27 merge) — feat/task-chaining, which this was originally stacked on, is now merged. 3 linear commits, no merge commits.

Verification

Run against the actual master-merged tree (2 fix commits rebased onto current master):

• cargo test: 554 pass, 0 fail, 1 ignored (+5 new detection tests; the 1 ignored is the long-standing env-gated test, unrelated).
• cargo clippy --all-targets --all-features -- -D clippy::all: clean.
• cargo fmt --check: clean. dprint check: clean.
• Rebase onto current master was conflict-free; zero functional overlap with intervening commits.

Notes

• CHANGELOG.md [0.11.0] updated: new ### Fixed section for this PR's behavior, plus a ### Changed entry for the go.mod-module-path task-name change that landed via Task chaining: run -s/-p chain mode + install <tasks> #27. Not bumping version as 0.11.0 is not published yet.
• Review of the diff (detect.rs, node.rs, files.rs) surfaced no code defects; the only flagged item — the Corepack/unparseable-packageManager interaction — was traced to source and confirmed correct.

[kjanat]

Superseded — rebuilding by hand-port off feat/task-chaining instead of copy/cherry-pick.

[coderabbitai]

📝 Walkthrough

Walkthrough

The PR enhances Node.js package manager detection and task extraction with workspace-aware ancestry walking. It introduces reusable upward-search infrastructure, adds workspace membership detection, enables PM fallback chains within monorepos, decouples script extraction from PM detection, and validates the new behavior with comprehensive tests.

Changes

Node.js workspace-aware package manager and task detection

Layer / File(s)	Summary
Ancestor-walking infrastructure with VCS boundaries src/tool/files.rs	find_in_ancestors centralizes upward-directory traversal with VCS-root boundary rules, accepting a predicate and returning the first Some result; find_first_upwards refactored to use this helper.
Workspace membership detection src/tool/node.rs	within_workspace_upwards scans ancestor directories for monorepo markers (pnpm-workspace.yaml, lerna.json, or package.json with workspaces key) using the new ancestor-walking infrastructure.
Package manager upward resolution within workspaces src/detect.rs	New detect_node_pm_upwards helper walks ancestors within JS workspaces to find governing PM via lockfile or manifest settings; integrated into detect_package_managers as final fallback in a staged chain after field-derived and manifest-derived PM options.
Task extraction decoupled from PM detection src/detect.rs	extract_tasks now independently decides on package.json script extraction based on local manifest presence, workspace membership, and Deno presence; spawn logic selects local extraction only when a local manifest exists and Deno is absent, otherwise uses upward extraction.
Regression and unit tests for workspace-aware detection src/detect.rs	Tests validate script extraction without lockfiles, workspace-member inheritance of ancestor scripts, prevention of adoption outside workspace boundaries, PM resolution from devEngines, and upward PM adoption for PM-less members.

Possibly related PRs

• kjanat/runner#13: Related changes to package.json script detection and Turbo passthrough classification.
• kjanat/runner#22: Overlapping modifications in src/detect.rs for package-manager and script detection logic.
• kjanat/runner#15: Related task extraction flow changes affecting Node/package.json handling.

Arrr, the code be tidied and true, no barnacles left to pick—
Ancestors walked stern to bow, workspace flags in tow,
Scripts now found whether ye be docked or adrift,
Warnings spit where legacy fields be stiff,
Patch hoisted, tests green—aye, that warms this pirate's heart. 🏴‍☠️

🚥 Pre-merge checks | ✅ 7 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Semver Version Bump Validation	⚠️ Warning	Source code modified (256 insertions across 3 .rs files) but Cargo.toml version unchanged at 0.11.0. PR adds new pub(crate) APIs and bug fixes—requires PATCH bump to 0.11.1.	Update Cargo.toml version from "0.11.0" to "0.11.1" to reflect bug fixes and new backward-compatible functionality additions.

✅ Passed checks (7 passed)

Check name	Status	Explanation
Title check	✅ Passed	Title uses 'fix:' prefix, is descriptive of the changes (decoupling script discovery from PM detection and mirroring PM chain), but exceeds the ideal 50-character limit at 88 characters.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Changelog Update	✅ Passed	CHANGELOG.md updated under [0.11.0] with comprehensive Fixed entries matching the three modified source files. Version header format correct, TBD date allowed per check rules.
Agents.Md Documentation Updated	✅ Passed	No AGENTS.md file exists in the repository. The custom check requires AGENTS.md to exist as a prerequisite before mandating updates. Since this file is absent, the check does not apply.
Description check	✅ Passed	The PR description is directly related to the changeset, detailing the problem (Node script discovery gated on PM detection in workspace members), the fixes (decoupling script discovery from PM detection, mirroring PM resolution chain, extracting shared ancestor-walk utility), and verification results.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

✨ Simplify code

• Create PR with simplified code
• Commit simplified code in branch fix/node-detection-decouple-tc

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