[zeroconfig] Implement nodejs detector (#2395)

## Summary

TSIA

Possible improvement: should we default `DEVBOX_COREPACK_ENABLED` to
true? (cc: @LucilleH )

## How was it tested?

- [x] unit tests
- [x] Manually created directory with package.json

pkg/autodetect/autodetect.go

@@ -42,6 +42,7 @@ func populateConfig(ctx context.Context, path string, config *devconfig.Config)
 func detectors(path string) []detector.Detector {
 	return []detector.Detector{
 		&detector.GoDetector{Root: path},
+		&detector.NodeJSDetector{Root: path},
 		&detector.PHPDetector{Root: path},
 		&detector.PoetryDetector{Root: path},
 		&detector.PythonDetector{Root: path},

pkg/autodetect/detector/nodejs.go

@@ -0,0 +1,71 @@
+package detector
+
+import (
+	"context"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"regexp"
+)
+
+type packageJSON struct {
+	Engines struct {
+		Node string `json:"node"`
+	} `json:"engines"`
+}
+
+type NodeJSDetector struct {
+	Root        string
+	packageJSON *packageJSON
+}
+
+var _ Detector = &NodeJSDetector{}
+
+func (d *NodeJSDetector) Init() error {
+	pkgJSON, err := loadPackageJSON(d.Root)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	d.packageJSON = pkgJSON
+	return nil
+}
+
+func (d *NodeJSDetector) Relevance(path string) (float64, error) {
+	if d.packageJSON == nil {
+		return 0, nil
+	}
+	return 1, nil
+}
+
+func (d *NodeJSDetector) Packages(ctx context.Context) ([]string, error) {
+	return []string{"nodejs@" + d.nodeVersion(ctx)}, nil
+}
+
+func (d *NodeJSDetector) nodeVersion(ctx context.Context) string {
+	if d.packageJSON == nil || d.packageJSON.Engines.Node == "" {
+		return "latest" // Default to latest if not specified
+	}
+
+	// Remove any non-semver characters (e.g. ">=", "^", etc)
+	version := "latest"
+	semverRegex := regexp.MustCompile(`\d+(\.\d+)?(\.\d+)?`)
+	if match := semverRegex.FindString(d.packageJSON.Engines.Node); match != "" {
+		version = match
+	}
+
+	return determineBestVersion(ctx, "nodejs", version)
+}
+
+func loadPackageJSON(root string) (*packageJSON, error) {
+	path := filepath.Join(root, "package.json")
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	var pkg packageJSON
+	if err := json.Unmarshal(data, &pkg); err != nil {
+		return nil, err
+	}
+	return &pkg, nil
+}

pkg/autodetect/detector/nodejs_test.go

@@ -0,0 +1,98 @@
+package detector
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+	"testing/fstest"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNodeJSDetector_Relevance(t *testing.T) {
+	tests := []struct {
+		name             string
+		fs               fstest.MapFS
+		expected         float64
+		expectedPackages []string
+	}{
+		{
+			name: "package.json in root",
+			fs: fstest.MapFS{
+				"package.json": &fstest.MapFile{
+					Data: []byte(`{}`),
+				},
+			},
+			expected:         1,
+			expectedPackages: []string{"nodejs@latest"},
+		},
+		{
+			name: "package.json with node version",
+			fs: fstest.MapFS{
+				"package.json": &fstest.MapFile{
+					Data: []byte(`{
+						"engines": {
+							"node": ">=18.0.0"
+						}
+					}`),
+				},
+			},
+			expected:         1,
+			expectedPackages: []string{"[email protected]"},
+		},
+		{
+			name: "no nodejs files",
+			fs: fstest.MapFS{
+				"main.py": &fstest.MapFile{
+					Data: []byte(``),
+				},
+				"requirements.txt": &fstest.MapFile{
+					Data: []byte(``),
+				},
+			},
+			expected:         0,
+			expectedPackages: []string{},
+		},
+		{
+			name:             "empty directory",
+			fs:               fstest.MapFS{},
+			expected:         0,
+			expectedPackages: []string{},
+		},
+	}
+
+	for _, curTest := range tests {
+		t.Run(curTest.name, func(t *testing.T) {
+			dir := t.TempDir()
+			for name, file := range curTest.fs {
+				fullPath := filepath.Join(dir, name)
+				err := os.MkdirAll(filepath.Dir(fullPath), 0o755)
+				require.NoError(t, err)
+				err = os.WriteFile(fullPath, file.Data, 0o644)
+				require.NoError(t, err)
+			}
+
+			d := &NodeJSDetector{Root: dir}
+			err := d.Init()
+			require.NoError(t, err)
+
+			score, err := d.Relevance(dir)
+			require.NoError(t, err)
+			assert.Equal(t, curTest.expected, score)
+			if score > 0 {
+				packages, err := d.Packages(context.Background())
+				require.NoError(t, err)
+				assert.Equal(t, curTest.expectedPackages, packages)
+			}
+		})
+	}
+}
+
+func TestNodeJSDetector_Packages(t *testing.T) {
+	d := &NodeJSDetector{}
+	packages, err := d.Packages(context.Background())
+	require.NoError(t, err)
+	assert.Equal(t, []string{"nodejs@latest"}, packages)
+}

pkg/autodetect/detector/php_test.go

@@ -13,14 +13,16 @@ import (
 
 func TestPHPDetector_Relevance(t *testing.T) {
 	tests := []struct {
-		name     string
-		fs       fstest.MapFS
-		expected float64
+		name             string
+		fs               fstest.MapFS
+		expected         float64
+		expectedPackages []string
 	}{
 		{
-			name:     "no composer.json",
-			fs:       fstest.MapFS{},
-			expected: 0,
+			name:             "no composer.json",
+			fs:               fstest.MapFS{},
+			expected:         0,
+			expectedPackages: nil,
 		},
 		{
 			name: "with composer.json",
@@ -33,7 +35,8 @@ func TestPHPDetector_Relevance(t *testing.T) {
 					}`),
 				},
 			},
-			expected: 1,
+			expected:         1,
+			expectedPackages: []string{"[email protected]"},
 		},
 	}
 
@@ -52,16 +55,23 @@ func TestPHPDetector_Relevance(t *testing.T) {
 			score, err := d.Relevance(dir)
 			require.NoError(t, err)
 			assert.Equal(t, curTest.expected, score)
+
+			if score > 0 {
+				packages, err := d.Packages(context.Background())
+				require.NoError(t, err)
+				assert.Equal(t, curTest.expectedPackages, packages)
+			}
 		})
 	}
 }
 
 func TestPHPDetector_Packages(t *testing.T) {
 	tests := []struct {
-		name          string
-		fs            fstest.MapFS
-		expectedPHP   string
-		expectedError bool
+		name             string
+		fs               fstest.MapFS
+		expectedPHP      string
+		expectedError    bool
+		expectedPackages []string
 	}{
 		{
 			name: "no php version specified",
@@ -72,7 +82,8 @@ func TestPHPDetector_Packages(t *testing.T) {
 					}`),
 				},
 			},
-			expectedPHP: "php@latest",
+			expectedPHP:      "php@latest",
+			expectedPackages: []string{"php@latest"},
 		},
 		{
 			name: "specific php version",
@@ -85,7 +96,8 @@ func TestPHPDetector_Packages(t *testing.T) {
 					}`),
 				},
 			},
-			expectedPHP: "[email protected]",
+			expectedPHP:      "[email protected]",
+			expectedPackages: []string{"[email protected]"},
 		},
 		{
 			name: "php version with patch",
@@ -98,7 +110,8 @@ func TestPHPDetector_Packages(t *testing.T) {
 					}`),
 				},
 			},
-			expectedPHP: "[email protected]",
+			expectedPHP:      "[email protected]",
+			expectedPackages: []string{"[email protected]"},
 		},
 		{
 			name: "invalid composer.json",
@@ -107,7 +120,8 @@ func TestPHPDetector_Packages(t *testing.T) {
 					Data: []byte(`invalid json`),
 				},
 			},
-			expectedError: true,
+			expectedError:    true,
+			expectedPackages: nil,
 		},
 	}
 
@@ -129,7 +143,7 @@ func TestPHPDetector_Packages(t *testing.T) {
 
 			packages, err := d.Packages(context.Background())
 			require.NoError(t, err)
-			assert.Equal(t, []string{curTest.expectedPHP}, packages)
+			assert.Equal(t, curTest.expectedPackages, packages)
 		})
 	}
 }
@@ -139,6 +153,7 @@ func TestPHPDetector_PHPExtensions(t *testing.T) {
 		name               string
 		fs                 fstest.MapFS
 		expectedExtensions []string
+		expectedPackages   []string
 	}{
 		{
 			name: "no extensions",
@@ -152,6 +167,7 @@ func TestPHPDetector_PHPExtensions(t *testing.T) {
 				},
 			},
 			expectedExtensions: []string{},
+			expectedPackages:   []string{"[email protected]"},
 		},
 		{
 			name: "multiple extensions",
@@ -170,6 +186,11 @@ func TestPHPDetector_PHPExtensions(t *testing.T) {
 				"php81Extensions.mbstring@latest",
 				"php81Extensions.imagick@latest",
 			},
+			expectedPackages: []string{
+				"[email protected]",
+				"php81Extensions.mbstring@latest",
+				"php81Extensions.imagick@latest",
+			},
 		},
 	}
 
@@ -188,6 +209,10 @@ func TestPHPDetector_PHPExtensions(t *testing.T) {
 			extensions, err := d.phpExtensions(context.Background())
 			require.NoError(t, err)
 			assert.ElementsMatch(t, curTest.expectedExtensions, extensions)
+
+			packages, err := d.Packages(context.Background())
+			require.NoError(t, err)
+			assert.ElementsMatch(t, curTest.expectedPackages, packages)
 		})
 	}
 }