Use "WRAPPER_ENABLED" environment variable to control wrapper enablement (#46)

Author: briandealwis

nodejs/wrapper.go

@@ -45,10 +45,11 @@ type nodeContext struct {
 }
 
 func main() {
-	logrus.SetLevel(logrusLevel())
+	env := envToMap(os.Environ())
+	logrus.SetLevel(logrusLevel(env))
+	
 	logrus.Debugln("Launched: ", os.Args)
 
-	env := envToMap(os.Environ())
 	// suppress npm warnings when node on PATH isn't the node used for npm
 	env["npm_config_scripts_prepend_node_path"] = "false"
 	nc := nodeContext{program: os.Args[0], args: os.Args[1:], env: env}
@@ -57,8 +58,13 @@ func main() {
 	}
 }
 
-func logrusLevel() logrus.Level {
-	v := os.Getenv("WRAPPER_VERBOSE")
+func isEnabled(env map[string]string) bool {
+	v, found := env["WRAPPER_ENABLED"]
+	return !found || (v != "0" && v != "false" && v != "no")
+}
+
+func logrusLevel(env map[string]string) logrus.Level {
+	v := env["WRAPPER_VERBOSE"]
 	if v != "" {
 		if l, err := logrus.ParseLevel(v); err == nil {
 			return l
@@ -73,6 +79,11 @@ func run(nc *nodeContext, stdin io.Reader, stdout, stderr io.Writer) error {
 		return fmt.Errorf("could not unwrap: %w", err)
 	}
 	logrus.Debugln("unwrapped: ", nc.program)
+	
+	if !isEnabled(nc.env) {
+		logrus.Info("wrapper disabled")
+		return nc.exec(stdin, stdout, stderr)
+	}
 
 	// Use an absolute path in case we're being run within a node_modules directory
 	// If there's an error, then hand off immediately to the real node.

nodejs/wrapper_test.go

@@ -18,6 +18,7 @@ package main
 
 import (
 	"bytes"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -28,6 +29,54 @@ import (
 	"testing"
 )
 
+func TestIsEnabled(t *testing.T) {
+	tests := []struct {
+		env      map[string]string
+		expected bool
+	}{
+		{
+			env:      nil,
+			expected: true,
+		},
+		{
+			env:      map[string]string{"WRAPPER_ENABLED": "1"},
+			expected: true,
+		},
+		{
+			env:      map[string]string{"WRAPPER_ENABLED": "true"},
+			expected: true,
+		},
+		{
+			env:      map[string]string{"WRAPPER_ENABLED": "yes"},
+			expected: true,
+		},
+		{
+			env:      map[string]string{"WRAPPER_ENABLED": ""},
+			expected: true,
+		},
+		{
+			env:      map[string]string{"WRAPPER_ENABLED": "0"},
+			expected: false,
+		},
+		{
+			env:      map[string]string{"WRAPPER_ENABLED": "no"},
+			expected: false,
+		},
+		{
+			env:      map[string]string{"WRAPPER_ENABLED": "false"},
+			expected: false,
+		},
+	}
+	for _, test := range tests {
+		t.Run(fmt.Sprintf("env: %v", test.env), func(t *testing.T) {
+			result := isEnabled(test.env)
+			if test.expected != result {
+				t.Errorf("expected %v but got %v", test.expected, result)
+			}
+		})
+	}
+}
+
 func TestFindScript(t *testing.T) {
 	tests := []struct {
 		description string
@@ -240,37 +289,37 @@ func TestNodeContext_unwrap(t *testing.T) {
 	tests := []struct {
 		description string
 		input       nodeContext
-		noErr      bool
+		noErr       bool
 		expected    string
 	}{
 		{
 			description: "no PATH leaves unchanged",
 			input:       nodeContext{program: originalNode},
-			noErr:      false,
+			noErr:       false,
 			expected:    originalNode,
 		},
 		{
 			description: "empty PATH leaves unchanged",
 			input:       nodeContext{program: originalNode, env: map[string]string{"PATH": ""}},
-			noErr:      false,
+			noErr:       false,
 			expected:    originalNode,
 		},
 		{
 			description: "no other node leaves unchanged",
 			input:       nodeContext{program: originalNode, env: map[string]string{"PATH": root}},
-			noErr:      false,
+			noErr:       false,
 			expected:    originalNode,
 		},
 		{
 			description: "first other node wins",
 			input:       nodeContext{program: originalNode, env: map[string]string{"PATH": root + string(os.PathListSeparator) + binPath + string(os.PathListSeparator) + sbinPath}},
-			noErr:      true,
+			noErr:       true,
 			expected:    binNode,
 		},
 		{
 			description: "first node wins when original not found",
 			input:       nodeContext{program: name, env: map[string]string{"PATH": root + string(os.PathListSeparator) + binPath + string(os.PathListSeparator) + sbinPath}},
-			noErr:      true,
+			noErr:       true,
 			expected:    binNode,
 		},
 	}
@@ -497,6 +546,12 @@ done
 			args:        []string{"node_modules/script.js", "--inspect"},
 			expected:    "node_modules/script.js\n--inspect\n",
 		},
+		{
+			description: "node_modules script: inspect left alone with WRAPPER_ENABLED=0",
+			args:        []string{"--inspect=9229", "./node_nodules/script.js"},
+			env:         map[string]string{"WRAPPER_ENABLED": "0"},
+			expected:    "--inspect=9229\n./node_nodules/script.js\n",
+		},
 		{
 			description: "node_modules script with inspect: seeds NODE_DEBUG",
 			args:        []string{"--inspect", "node_modules/script.js"},