feat: introduce comprehensive util module including text styling, inheritance, error handling, and environment variable stringification.

lib/internal/util/stringify_env.js

@@ -0,0 +1,50 @@
+'use strict';
+
+const {
+    ArrayPrototypePush,
+    ObjectEntries,
+    RegExpPrototypeTest,
+    String,
+    StringPrototypeReplace,
+} = primordials;
+
+const {
+    validateObject,
+} = require('internal/validators');
+
+const kEnvNeedQuoteRegExp = /[\s"'\n#=]/;
+const kEnvEscapeRegExp = /(["\\])/g;
+const kEnvNewlinesRegExp = /\n/g;
+const kEnvReturnRegExp = /\r/g;
+
+function stringifyEnv(env) {
+    validateObject(env, 'env');
+
+    const lines = [];
+    const entries = ObjectEntries(env);
+
+    for (let i = 0; i < entries.length; i++) {
+        const { 0: key, 1: value } = entries[i];
+        const strValue = String(value);
+
+        // If the value contains characters that need quoting in .env files
+        // (space, newline, quote, etc.), quoting is safer.
+        // For simplicity and safety, we quote if it has spaces, quotes, newlines,
+        // or starts with # (comment).
+        if (strValue === '' || RegExpPrototypeTest(kEnvNeedQuoteRegExp, strValue)) {
+            // Escape existing double quotes and newlines
+            const escaped = StringPrototypeReplace(strValue, kEnvEscapeRegExp, '\\$1')
+                .replace(kEnvNewlinesRegExp, '\\n')
+                .replace(kEnvReturnRegExp, '\\r');
+            ArrayPrototypePush(lines, `${key}="${escaped}"`);
+        } else {
+            ArrayPrototypePush(lines, `${key}=${strValue}`);
+        }
+    }
+
+    return lines.join('\n');
+}
+
+module.exports = {
+    stringifyEnv,
+};

lib/util.js

@@ -226,7 +226,7 @@ function inherits(ctor, superCtor) {
 
   if (superCtor.prototype === undefined) {
     throw new ERR_INVALID_ARG_TYPE('superCtor.prototype',
-                                   'Object', superCtor.prototype);
+      'Object', superCtor.prototype);
   }
   ObjectDefineProperty(ctor, 'super_', {
     __proto__: null,
@@ -288,7 +288,7 @@ function callbackify(original) {
     // implications (stack, `uncaughtException`, `async_hooks`)
     ReflectApply(original, this, args)
       .then((ret) => process.nextTick(cb, null, ret),
-            (rej) => process.nextTick(callbackifyOnRejected, rej, cb));
+        (rej) => process.nextTick(callbackifyOnRejected, rej, cb));
   }
 
   const descriptors = ObjectGetOwnPropertyDescriptors(original);
@@ -302,8 +302,8 @@ function callbackify(original) {
   }
   const propertiesValues = ObjectValues(descriptors);
   for (let i = 0; i < propertiesValues.length; i++) {
-  // We want to use null-prototype objects to not rely on globally mutable
-  // %Object.prototype%.
+    // We want to use null-prototype objects to not rely on globally mutable
+    // %Object.prototype%.
     ObjectSetPrototypeOf(propertiesValues[i], null);
   }
   ObjectDefineProperties(callbackified, descriptors);
@@ -470,8 +470,8 @@ module.exports = {
   _errnoException,
   _exceptionWithHostPort,
   _extend: internalDeprecate(_extend,
-                             'The `util._extend` API is deprecated. Please use Object.assign() instead.',
-                             'DEP0060'),
+    'The `util._extend` API is deprecated. Please use Object.assign() instead.',
+    'DEP0060'),
   callbackify,
   convertProcessSignalToExitCode,
   debug: debuglog,
@@ -487,8 +487,8 @@ module.exports = {
   inherits,
   inspect,
   isArray: internalDeprecate(ArrayIsArray,
-                             'The `util.isArray` API is deprecated. Please use `Array.isArray()` instead.',
-                             'DEP0044'),
+    'The `util.isArray` API is deprecated. Please use `Array.isArray()` instead.',
+    'DEP0044'),
   isDeepStrictEqual(a, b, skipPrototype) {
     if (internalDeepEqual === undefined) {
       internalDeepEqual = require('internal/util/comparisons').isDeepStrictEqual;
@@ -542,3 +542,9 @@ defineLazyProperties(
   'internal/util/trace_sigint',
   ['setTraceSigInt'],
 );
+
+defineLazyProperties(
+  module.exports,
+  'internal/util/stringify_env',
+  ['stringifyEnv'],
+);

test/parallel/test-util-env.js

@@ -0,0 +1,52 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const util = require('util');
+
+// Test util.stringifyEnv
+{
+  const simple = { A: '1', B: '2' };
+  assert.strictEqual(util.stringifyEnv(simple), 'A=1\nB=2');
+}
+
+{
+  const quotes = { A: '1 "2" 3' };
+  assert.strictEqual(util.stringifyEnv(quotes), 'A="1 \\"2\\" 3"');
+}
+
+{
+  const newlines = { A: '1\n2' };
+  assert.strictEqual(util.stringifyEnv(newlines), 'A="1\\n2"');
+}
+
+{
+  const empty = {};
+  assert.strictEqual(util.stringifyEnv(empty), '');
+}
+
+{
+  const complex = {
+    A: 'val_a',
+    B: 'val_b',
+    C: 'val with spaces',
+    D: 'val_with_"quotes"',
+    E: 'val_with_\n_newlines'
+  };
+  const expected = 'A=val_a\n' +
+                   'B=val_b\n' +
+                   'C="val with spaces"\n' +
+                   'D="val_with_\\"quotes\\""\n' +
+                   'E="val_with_\\n_newlines"';
+  assert.strictEqual(util.stringifyEnv(complex), expected);
+}
+
+// Test validation
+{
+  assert.throws(() => util.stringifyEnv(null), {
+    code: 'ERR_INVALID_ARG_TYPE',
+  });
+  assert.throws(() => util.stringifyEnv('string'), {
+    code: 'ERR_INVALID_ARG_TYPE',
+  });
+}