fix(install): call a version-manager global install global, not project-local

Author: ArtemKosolap

src/__tests__/selfupdate/detect.test.ts

@@ -30,6 +30,41 @@ describe('how_installed', ()=>{
         expect(info.kind).toBe('npm-local');
     });
 
+    it('calls it local when the owning project is an ancestor of the working directory', ()=>{
+        // node resolves upward, so a copy in /home/artem/app/node_modules is
+        // this project's whether you stand in app or in app/src.
+        const project = at('home', 'artem', 'app');
+        const info = how_installed({
+            module_dir: path.join(project, 'node_modules', 'reply-cli'),
+            cwd: path.join(project, 'src', 'deep'),
+            read_package: pkg('reply-cli'),
+        });
+        expect(info.kind).toBe('npm-local');
+    });
+
+    it('still calls a version-manager install global from the home directory', ()=>{
+        // The regression that matters: ~/.nvm/... is under $HOME, so asking
+        // whether the module sits under cwd would call this project-local and
+        // refuse to update the one install we can actually drive.
+        const home = at('home', 'artem');
+        const info = how_installed({
+            module_dir: path.join(home, '.nvm', 'versions', 'node', 'v22.17.1', 'lib', 'node_modules', 'reply-cli'),
+            cwd: home,
+            read_package: pkg('reply-cli'),
+        });
+        expect(info.kind).toBe('npm-global');
+    });
+
+    it('attributes a nested copy to the project that owns the tree', ()=>{
+        const project = at('home', 'artem', 'app');
+        const info = how_installed({
+            module_dir: path.join(project, 'node_modules', 'some-tool', 'node_modules', 'reply-cli'),
+            cwd: project,
+            read_package: pkg('reply-cli'),
+        });
+        expect(info.kind).toBe('npm-local');
+    });
+
     it('recognises npx before node_modules, since an npx cache has both', ()=>{
         const info = how_installed({
             module_dir: at('home', 'artem', '.npm', '_npx', 'a1b2', 'node_modules', 'reply-cli'),

src/selfupdate/detect.ts

@@ -44,18 +44,34 @@ const inside = (parent: string, child: string): boolean=>{
     return rel !== '' && !rel.startsWith('..') && !path.isAbsolute(rel);
 };
 
+// The directory whose node_modules holds this package — its first one, so a
+// transitive copy under a nested node_modules is still attributed to the
+// project that owns the tree.
+const owning_project = (module_dir: string, first_node_modules: number): string=>{
+    const depth = module_dir.split(/[\\/]+/).length - first_node_modules;
+    return path.resolve(module_dir, ...Array<string>(depth).fill('..'));
+};
+
 const classify = (module_dir: string, cwd: string): Install_kind=>{
     const parts = module_dir.split(/[\\/]+/);
     // Checked before node_modules on purpose: an npx cache contains both.
     if (parts.includes('_npx'))
     {
         return 'npx';
     }
-    if (parts.includes('node_modules'))
+    const at = parts.indexOf('node_modules');
+    if (at === -1)
     {
-        return inside(cwd, module_dir) ? 'npm-local' : 'npm-global';
+        return 'source';
     }
-    return 'source';
+    // Local means node resolves it by walking up from the working directory,
+    // so the owning project must BE the working directory or an ancestor of
+    // it. Asking only whether module_dir sits under cwd gets this backwards
+    // for a version-manager install — ~/.nvm/.../node_modules is under $HOME,
+    // and a user standing in $HOME would see their global install called
+    // project-local, with the update refused for a project that isn't there.
+    const project = owning_project(module_dir, at);
+    return project === cwd || inside(project, cwd) ? 'npm-local' : 'npm-global';
 };
 
 const how_installed = (deps: Detect_deps = {}): Install_info=>{