fix(ls): suppress false UNMET DEPENDENCYs in linked strategy

lib/commands/ls.js

@@ -57,6 +57,7 @@ class LS extends ArboristWorkspaceCmd {
     const unicode = this.npm.config.get('unicode')
     const packageLockOnly = this.npm.config.get('package-lock-only')
     const workspacesEnabled = this.npm.flatOptions.workspacesEnabled
+    const installStrategy = this.npm.flatOptions.installStrategy
 
     const path = global ? resolve(this.npm.globalDir, '..') : this.npm.prefix
 
@@ -136,6 +137,9 @@ class LS extends ArboristWorkspaceCmd {
               link,
               omit,
             }) : () => true)
+            .filter(installStrategy === 'linked'
+              ? filterLinkedStrategyEdges({ node, currentDepth })
+              : () => true)
             .map(mapEdgesToNodes({ seenPaths }))
             .concat(appendExtraneousChildren({ node, seenPaths }))
             .sort(sortAlphabetically)
@@ -403,6 +407,36 @@ const getJsonOutputItem = (node, { global, long }) => {
   return augmentItemWithIncludeMetadata(node, item)
 }
 
+// In linked strategy, two types of edges produce false UNMET DEPENDENCYs:
+// 1. Workspace edges for undeclared workspaces: the lockfile records edges from root to ALL workspaces, but only declared workspaces are hoisted to root/node_modules in linked mode.  Undeclared ones are intentionally absent.
+// 2. Dev edges on non-root packages: store package link targets have no parent in the node tree, so they are treated as "top" nodes and their devDependencies are loaded as edges.  Those devDeps are never installed.
+const filterLinkedStrategyEdges = ({ node, currentDepth }) => {
+  const declaredDeps = currentDepth === 0
+    ? new Set(Object.keys(Object.assign({},
+      node.target.package.dependencies,
+      node.target.package.devDependencies,
+      node.target.package.optionalDependencies,
+      node.target.package.peerDependencies
+    )))
+    : null
+
+  return (edge) => {
+    // Skip workspace edges for undeclared workspaces at root level
+    if (currentDepth === 0 && edge.type === 'workspace' && edge.missing) {
+      if (!declaredDeps.has(edge.name)) {
+        return false
+      }
+    }
+
+    // Skip dev edges for non-root packages (store packages)
+    if (currentDepth > 0 && edge.dev) {
+      return false
+    }
+
+    return true
+  }
+}
+
 const filterByEdgesTypes = ({ link, omit }) => (edge) => {
   for (const omitType of omit) {
     if (edge[omitType]) {

test/lib/commands/ls.js

@@ -5301,3 +5301,107 @@ t.test('completion', async t => {
   const res = await ls.completion({ conf: { argv: { remain: ['npm', 'ls'] } } })
   t.type(res, Array)
 })
+
+t.test('ls --install-strategy=linked', async t => {
+  t.test('should not report undeclared workspaces as UNMET DEPENDENCY', async t => {
+    const { result, ls } = await mockLs(t, {
+      config: {
+        'install-strategy': 'linked',
+      },
+      prefixDir: {
+        'package.json': JSON.stringify({
+          name: 'test-linked-ws',
+          version: '1.0.0',
+          workspaces: ['packages/*'],
+          dependencies: { 'workspace-a': '*' },
+        }),
+        packages: {
+          'workspace-a': {
+            'package.json': JSON.stringify({
+              name: 'workspace-a',
+              version: '1.0.0',
+            }),
+          },
+          'workspace-b': {
+            'package.json': JSON.stringify({
+              name: 'workspace-b',
+              version: '1.0.0',
+            }),
+          },
+        },
+        node_modules: {
+          'workspace-a': t.fixture('symlink', '../packages/workspace-a'),
+          // workspace-b intentionally NOT linked (undeclared in dependencies)
+        },
+      },
+    })
+    await ls.exec([])
+    const output = cleanCwd(result())
+    t.notMatch(output, /UNMET DEPENDENCY/, 'should not report undeclared workspace as UNMET DEPENDENCY')
+    t.match(output, /workspace-a/, 'should list declared workspace')
+  })
+
+  t.test('should not report devDeps of store packages as UNMET DEPENDENCY', async t => {
+    const { result, ls } = await mockLs(t, {
+      config: {
+        'install-strategy': 'linked',
+      },
+      prefixDir: {
+        'package.json': JSON.stringify({
+          name: 'test-linked-store',
+          version: '1.0.0',
+          dependencies: { nopt: '^1.0.0' },
+        }),
+        node_modules: {
+          nopt: t.fixture('symlink', '.store/nopt@1.0.0/node_modules/nopt'),
+          '.store': {
+            'nopt@1.0.0': {
+              node_modules: {
+                nopt: {
+                  'package.json': JSON.stringify({
+                    name: 'nopt',
+                    version: '1.0.0',
+                    devDependencies: { tap: '^16.0.0' },
+                  }),
+                },
+              },
+            },
+          },
+        },
+      },
+    })
+    await ls.exec([])
+    const output = cleanCwd(result())
+    t.notMatch(output, /UNMET DEPENDENCY/, 'should not report devDeps of store packages')
+    t.match(output, /nopt/, 'should list the dependency')
+  })
+
+  t.test('should still report declared workspace as UNMET DEPENDENCY when missing', async t => {
+    const { ls } = await mockLs(t, {
+      config: {
+        'install-strategy': 'linked',
+      },
+      prefixDir: {
+        'package.json': JSON.stringify({
+          name: 'test-linked-ws-missing',
+          version: '1.0.0',
+          workspaces: ['packages/*'],
+          dependencies: { 'workspace-a': '*' },
+        }),
+        packages: {
+          'workspace-a': {
+            'package.json': JSON.stringify({
+              name: 'workspace-a',
+              version: '1.0.0',
+            }),
+          },
+        },
+        node_modules: {
+          // workspace-a is declared but its symlink is missing
+        },
+      },
+    })
+    await t.rejects(ls.exec([]), { code: 'ELSPROBLEMS' },
+      'should report declared workspace as UNMET DEPENDENCY')
+  })
+})