feat(build): detect root frontend manifests

pkg/build/discovery.go

@@ -239,7 +239,8 @@ type DiscoveryResult struct {
 	Types []ProjectType
 	// PrimaryStack is the best stack suggestion based on detected types.
 	PrimaryStack string
-	// HasFrontend is true when frontend/package.json or subtree npm is found.
+	// HasFrontend is true when a root or frontend/ package.json/deno manifest is found,
+	// or when a nested frontend tree is detected.
 	HasFrontend bool
 	// HasSubtreeNpm is true when a nested package.json exists within depth 2.
 	HasSubtreeNpm bool
@@ -285,8 +286,9 @@ func DiscoverFull(fs io.Medium, dir string) (*DiscoveryResult, error) {
 	// Subtree npm detection
 	result.HasSubtreeNpm = HasSubtreeNpm(fs, dir)
 
-	// Frontend detection: frontend package managers or nested frontend manifests.
-	result.HasFrontend = hasFrontendManifest(fs, ax.Join(dir, "frontend")) ||
+	// Frontend detection: root manifests, frontend/ manifests, or nested frontend trees.
+	result.HasFrontend = hasFrontendManifest(fs, dir) ||
+		hasFrontendManifest(fs, ax.Join(dir, "frontend")) ||
 		hasSubtreeFrontendManifest(fs, dir) ||
 		result.HasSubtreeNpm
 

pkg/build/discovery_test.go

@@ -583,6 +583,18 @@ func TestDiscovery_DiscoverFull_Good(t *testing.T) {
 		assert.True(t, result.HasFrontend)
 	})
 
+	t.Run("detects root package.json as frontend", func(t *testing.T) {
+		dir := t.TempDir()
+		require.NoError(t, ax.WriteFile(ax.Join(dir, "package.json"), []byte("{}"), 0644))
+
+		result, err := DiscoverFull(fs, dir)
+		require.NoError(t, err)
+		assert.Equal(t, []ProjectType{ProjectTypeNode}, result.Types)
+		assert.Equal(t, "node", result.PrimaryStack)
+		assert.True(t, result.HasFrontend)
+		assert.False(t, result.HasSubtreeNpm)
+	})
+
 	t.Run("detects frontend deno manifest at project root", func(t *testing.T) {
 		dir := t.TempDir()
 		err := ax.WriteFile(ax.Join(dir, "go.mod"), []byte("{}"), 0644)