WIP: Adding colorText method to util.

lib/util.js

@@ -64,6 +64,7 @@ const { debuglog } = require('internal/util/debuglog');
 const {
   validateFunction,
   validateNumber,
+  validateString
 } = require('internal/validators');
 const { TextDecoder, TextEncoder } = require('internal/encoding');
 const { isBuffer } = require('buffer').Buffer;
@@ -331,12 +332,29 @@ function getSystemErrorName(err) {
   return internalErrorName(err);
 }
 
+/**
+ * @param {string} format
+ * @param {string} text
+ * @returns {string}
+ */
+ function colorText(format, text) {
+  validateString(format, 'format');
+  validateString(text, 'text');
+  const formatCodes = inspect.colors[format];
+  if (!ArrayIsArray(formatCodes)) {
+    return text;
+  }
+  return `\u001b[${formatCodes[0]}m${txt}\u001b[${formatCodes[1]}m`;
+
+}
+
 // Keep the `exports =` so that various functions can still be monkeypatched
 module.exports = {
   _errnoException: errnoException,
   _exceptionWithHostPort: exceptionWithHostPort,
   _extend,
   callbackify,
+  colorText,
   debug: debuglog,
   debuglog,
   deprecate,

test/parallel/test-util-colorText.js

@@ -0,0 +1,22 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+const util = require('../../lib/util');
+const symbol = Symbol('foo');
+
+
+[
+  undefined,
+  null,
+  false,
+  5n,
+  5,
+  Symbol(),
+].forEach((invalidOption) => {
+  assert.throws(() => {
+    util.colorText(invalidOption, 'test');
+  }, {
+    code: 'ERR_INVALID_ARG_TYPE',
+    message: /"format" argument must be an string/
+  });
+});