console: colorize console error and warn

lib/internal/console/constructor.js

@@ -8,6 +8,7 @@ const {
   ArrayIsArray,
   ArrayPrototypeForEach,
   ArrayPrototypePush,
+  ArrayPrototypeSome,
   ArrayPrototypeUnshift,
   Boolean,
   ErrorCaptureStackTrace,
@@ -67,6 +68,7 @@ const {
   CHAR_LOWERCASE_N: kTraceInstant,
   CHAR_UPPERCASE_C: kTraceCount,
 } = require('internal/constants');
+const { styleText } = require('util');
 const kCounts = Symbol('counts');
 
 const kTraceConsoleCategory = 'node,node.console';
@@ -273,7 +275,7 @@ ObjectDefineProperties(Console.prototype, {
   [kWriteToConsole]: {
     __proto__: null,
     ...consolePropAttributes,
-    value: function(streamSymbol, string) {
+    value: function(streamSymbol, string, color = '') {
       const ignoreErrors = this._ignoreErrors;
       const groupIndent = this[kGroupIndent];
 
@@ -288,6 +290,11 @@ ObjectDefineProperties(Console.prototype, {
         }
         string = groupIndent + string;
       }
+
+      if (color) {
+        string = styleText(color, string);
+      }
+
       string += '\n';
 
       if (ignoreErrors === false) return stream.write(string);
@@ -378,12 +385,15 @@ const consoleMethods = {
   log(...args) {
     this[kWriteToConsole](kUseStdout, this[kFormatForStdout](args));
   },
-
-
   warn(...args) {
-    this[kWriteToConsole](kUseStderr, this[kFormatForStderr](args));
+    const color = (shouldColorize(args) && 'yellow') || '';
+    this[kWriteToConsole](kUseStderr, this[kFormatForStderr](args), color);
   },
 
+  error(...args) {
+    const color = (shouldColorize(args) && 'red') || '';
+    this[kWriteToConsole](kUseStderr, this[kFormatForStderr](args), color);
+  },
 
   dir(object, options) {
     this[kWriteToConsole](kUseStdout, inspect(object, {
@@ -681,6 +691,12 @@ const iterKey = '(iteration index)';
 
 const isArray = (v) => ArrayIsArray(v) || isTypedArray(v) || isBuffer(v);
 
+// TODO: remove string type check once the styleText supports objects
+// Return true if all args are type string
+const shouldColorize = (args) => {
+  return lazyUtilColors().hasColors && !ArrayPrototypeSome(args, (arg) => typeof arg !== 'string');
+};
+
 function noop() {}
 
 for (const method of ReflectOwnKeys(consoleMethods))
@@ -689,7 +705,6 @@ for (const method of ReflectOwnKeys(consoleMethods))
 Console.prototype.debug = Console.prototype.log;
 Console.prototype.info = Console.prototype.log;
 Console.prototype.dirxml = Console.prototype.log;
-Console.prototype.error = Console.prototype.warn;
 Console.prototype.groupCollapsed = Console.prototype.group;
 
 function initializeGlobalConsole(globalConsole) {

test/parallel/test-repl.js

@@ -770,6 +770,7 @@ const errorTests = [
       'Object [console] {',
       '  log: [Function: log],',
       '  warn: [Function: warn],',
+      '  error: [Function: error],',
       '  dir: [Function: dir],',
       '  time: [Function: time],',
       '  timeEnd: [Function: timeEnd],',
@@ -785,7 +786,6 @@ const errorTests = [
       / {2}debug: \[Function: (debug|log)],/,
       / {2}info: \[Function: (info|log)],/,
       / {2}dirxml: \[Function: (dirxml|log)],/,
-      / {2}error: \[Function: (error|warn)],/,
       / {2}groupCollapsed: \[Function: (groupCollapsed|group)],/,
       / {2}Console: \[Function: Console],?/,
       ...process.features.inspector ? [

test/pseudo-tty/test-tty-color-support-warning-2.out

@@ -1,3 +1,3 @@
 
-(node:*) Warning: The 'NODE_DISABLE_COLORS' env is ignored due to the 'FORCE_COLOR' env being set.
-(Use `* --trace-warnings ...` to show where the warning was created)
+*(node:*) Warning: The 'NODE_DISABLE_COLORS' env is ignored due to the 'FORCE_COLOR' env being set.
+(Use `* --trace-warnings ...` to show where the warning was created)*

test/pseudo-tty/test-tty-color-support-warning.out

@@ -1,3 +1,3 @@
 
-(node:*) Warning: The 'NODE_DISABLE_COLORS' and 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
-(Use `* --trace-warnings ...` to show where the warning was created)
+*(node:*) Warning: The 'NODE_DISABLE_COLORS' and 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
+(Use `* --trace-warnings ...` to show where the warning was created)*

test/pseudo-tty/test-tty-color-support.out

@@ -1,2 +1,2 @@
-(node:*) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
-(Use `* --trace-warnings ...` to show where the warning was created)
+*(node:*) Warning: The 'NO_COLOR' env is ignored due to the 'FORCE_COLOR' env being set.
+(Use `* --trace-warnings ...` to show where the warning was created)*