Description

The PR fixes the manifestsByPath[rootDir] crash by changing the selectProjectByDir graph key,
but it does not add/update any automated test to prevent the regression from returning. This
violates the requirement to add regression coverage that would fail on the prior crashing behavior
and pass with the fix.

Code

installing/commands/src/installDeps.ts[R519-530]

function selectProjectByDir (projects: Project[], searchedDir: string): ProjectsGraph | undefined {
const project = projects.find(({ rootDir }) => path.relative(rootDir, searchedDir) === '')
if (project == null) return undefined
-  return { [searchedDir]: { dependencies: [], package: project } }
+  // Key the graph by `project.rootDir`, not `searchedDir`. Downstream
+  // `recursive()` builds `manifestsByPath` from `projects` (keyed by
+  // `project.rootDir`) and then iterates `Object.keys(selectedProjectsGraph)`
+  // to look up `manifestsByPath[rootDir]`. On Windows, `opts.dir` and
+  // `project.rootDir` can end up with different drive-letter casing or path
+  // separators after platform normalization, leaving the lookup `undefined`
+  // and surfacing as `Cannot destructure property 'manifest' of
+  // 'manifestsByPath[rootDir]' as it is undefined`.
+  return { [project.rootDir]: { dependencies: [], package: project } }

Evidence

Compliance ID 2 requires new/updated automated regression coverage explicitly asserting the prior
crash does not occur. The PR changes production code in selectProjectByDir (in both call sites)
but does not include any corresponding test change to exercise the mismatched opts.dir vs
project.rootDir scenario and assert pnpm add does not throw.

Add regression coverage for the pnpm add crash related to missing rootDir manifest
installing/commands/src/installDeps.ts[519-531]
installing/commands/src/import/index.ts[337-345]
.changeset/fix-windows-recursive-undefined-manifest.md[1-6]

Agent prompt

The issue below was found during a code review. Follow the provided context and guidance below and implement a solution

## Issue description
PR Compliance requires adding automated regression coverage for the Windows/non-workspace `pnpm add` crash where `manifestsByPath[rootDir]` was `undefined` and destructuring `manifest` crashed.
## Issue Context
The fix changes `selectProjectByDir` to key the single-entry `ProjectsGraph` by `project.rootDir` instead of `searchedDir`/`opts.dir`, preventing mismatched normalized paths (notably drive-letter casing on Windows) from causing `manifestsByPath[rootDir]` lookup to return `undefined`.
## Fix Focus Areas
- installing/commands/test/add.ts[331-413]
- installing/commands/src/installDeps.ts[519-531]
- installing/commands/src/import/index.ts[337-345]

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Walkthrough

Two one-line fixes in selectProjectByDir change the ProjectsGraph key from the caller-supplied searchedDir to the matched project.rootDir in both installDeps.ts and import/index.ts. A regression test is added to add.ts and a changeset entry documents the patch.

Changes

Windows Path Normalization Fix

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Suggested reviewers

• zkochan

Poem

🐇 A key was the culprit, mismatched by a letter,
The drive said "C:" but the map knew it better.
Now rootDir aligns with the path that we store,
No more undefined manifests to deplore.
Hop hop, Windows friends — pnpm works once more! 🪟

❌ Failed checks (1 warning)

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

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• Key single-project ProjectsGraph entries by project.rootDir for consistent downstream lookups.
• Prevent Windows non-workspace pnpm add crash caused by path normalization differences.
• Add changeset documenting the regression fix and patch release impact.

The following are alternative approaches to this PR:

Recommendation: The PR’s approach is the best tradeoff: keying the single-entry ProjectsGraph by project.rootDir fixes the mismatch at the source with minimal behavioral surface area. The alternatives (path canonicalization or tolerant lookup) are broader changes with higher platform/edge-case risk than necessary for this regression.

index.ts Key single-project ProjectsGraph by project.rootDir in import flow +5/-1

Key single-project ProjectsGraph by project.rootDir in import flow

• Changes selectProjectByDir to return a ProjectsGraph keyed by project.rootDir instead of the searched directory. Prevents downstream manifestsByPath lookups from failing when path normalization differs (e.g., Windows drive-letter casing).

installing/commands/src/import/index.ts

---

installDeps.ts Key single-project ProjectsGraph by project.rootDir in non-workspace install flow +9/-1

Key single-project ProjectsGraph by project.rootDir in non-workspace install flow

• Updates selectProjectByDir to key the returned ProjectsGraph by project.rootDir, aligning with recursive()’s manifestsByPath indexing. Avoids undefined manifest destructuring when opts.dir and project.rootDir normalize differently on Windows.

installing/commands/src/installDeps.ts

---

fix-windows-recursive-undefined-manifest.md Add changeset for Windows non-workspace 'pnpm add' crash regression +6/-0

Add changeset for Windows non-workspace 'pnpm add' crash regression

• Introduces a patch-level changeset for @pnpm/installing.commands and pnpm. Documents the Windows-only crash scenario, root cause (graph key mismatch), and links to pnpm/pnpm#12379.

.changeset/fix-windows-recursive-undefined-manifest.md

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