fix: resolving peer deps from deps of root project (#3559)

.changeset/late-ducks-relate.md

@@ -0,0 +1,5 @@
+---
+"@pnpm/resolve-dependencies": patch
+---
+
+Dependencies from the root workspace package should be used to resolve peer dependencies of any projects in the workspace.

packages/resolve-dependencies/src/resolveDependencyTree.ts

@@ -116,7 +116,7 @@ export default async function<T> (
     // This may be optimized.
     // We only need to proceed resolving every dependency
     // if the newly added dependency has peer dependencies.
-    const proceed = importer.hasRemovedDependencies === true || importer.wantedDependencies.some((wantedDep) => wantedDep['isNew'])
+    const proceed = importer.id === '.' || importer.hasRemovedDependencies === true || importer.wantedDependencies.some((wantedDep) => wantedDep['isNew'])
     const resolveOpts = {
       currentDepth: 0,
       parentPkg: {

packages/supi/test/install/peerDependencies.ts

@@ -207,7 +207,7 @@ test('peer dependency is resolved from the dependencies of the workspace root pr
     {
       buildIndex: 0,
       manifest: {
-        name: 'root',
+        name: 'pkg',
         version: '1.0.0',
 
         dependencies: {
@@ -223,8 +223,45 @@ test('peer dependency is resolved from the dependencies of the workspace root pr
     message: 'ajv-keywords@1.5.0 requires a peer of ajv@>=4.10.0 but none was installed.',
   })
 
-  const lockfile = await projects.root.readLockfile()
-  expect(lockfile.importers.pkg?.dependencies?.['ajv-keywords']).toBe('1.5.0_ajv@4.10.0')
+  {
+    const lockfile = await projects.root.readLockfile()
+    expect(lockfile.importers.pkg?.dependencies?.['ajv-keywords']).toBe('1.5.0_ajv@4.10.0')
+  }
+
+  await mutateModules([
+    {
+      buildIndex: 0,
+      manifest: {
+        name: 'root',
+        version: '1.0.0',
+
+        dependencies: {
+          ajv: '4.10.0',
+        },
+      },
+      mutation: 'install',
+      rootDir: process.cwd(),
+    },
+    {
+      buildIndex: 0,
+      manifest: {
+        name: 'pkg',
+        version: '1.0.0',
+
+        dependencies: {
+          'ajv-keywords': '1.5.0',
+          'is-positive': '1.0.0',
+        },
+      },
+      mutation: 'install',
+      rootDir: path.resolve('pkg'),
+    },
+  ], await testDefaults({ reporter }))
+
+  {
+    const lockfile = await projects.root.readLockfile()
+    expect(lockfile.importers.pkg?.dependencies?.['ajv-keywords']).toBe('1.5.0_ajv@4.10.0')
+  }
 })
 
 test('warning is reported when cannot resolve peer dependency for non-top-level dependency', async () => {