console: colorize console error and warn

prints console error in red and warn in yellow

Author: MrJithil

lib/internal/console/constructor.js

@@ -273,7 +273,7 @@ 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 +288,11 @@ ObjectDefineProperties(Console.prototype, {
         }
         string = groupIndent + string;
       }
+
+      if (color && lazyUtilColors().hasColors) {
+        string = `${color}${string}${lazyUtilColors().clear}`;
+      }
+
       string += '\n';
 
       if (ignoreErrors === false) return stream.write(string);
@@ -381,9 +386,14 @@ const consoleMethods = {
 
 
   warn(...args) {
-    this[kWriteToConsole](kUseStderr, this[kFormatForStderr](args));
+    const color = typeof args === 'string' ? lazyUtilColors().yellow : null;
+    this[kWriteToConsole](kUseStderr, this[kFormatForStderr](args), color);
   },
 
+  error(...args) {
+    const color = typeof args === 'string' ? lazyUtilColors().red : null;
+    this[kWriteToConsole](kUseStderr, this[kFormatForStderr](args), color);
+  },
 
   dir(object, options) {
     this[kWriteToConsole](kUseStdout, inspect(object, {
@@ -689,7 +699,6 @@ 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) {

lib/internal/util/colors.js

@@ -1,18 +1,26 @@
 'use strict';
 
+const {
+  ObjectKeys,
+} = primordials;
+
 let internalTTy;
 function lazyInternalTTY() {
   internalTTy ??= require('internal/tty');
   return internalTTy;
 }
 
+const colorsMap = {
+  blue: '\u001b[34m',
+  green: '\u001b[32m',
+  white: '\u001b[39m',
+  yellow: '\u001b[33m',
+  red: '\u001b[31m',
+  gray: '\u001b[90m',
+  clear: '\u001b[0m',
+};
+
 module.exports = {
-  blue: '',
-  green: '',
-  white: '',
-  red: '',
-  gray: '',
-  clear: '',
   hasColors: false,
   shouldColorize(stream) {
     if (process.env.FORCE_COLOR !== undefined) {
@@ -23,17 +31,13 @@ module.exports = {
         stream.getColorDepth() > 2 : true);
   },
   refresh() {
-    if (process.stderr.isTTY) {
-      const hasColors = module.exports.shouldColorize(process.stderr);
-      module.exports.blue = hasColors ? '\u001b[34m' : '';
-      module.exports.green = hasColors ? '\u001b[32m' : '';
-      module.exports.white = hasColors ? '\u001b[39m' : '';
-      module.exports.yellow = hasColors ? '\u001b[33m' : '';
-      module.exports.red = hasColors ? '\u001b[31m' : '';
-      module.exports.gray = hasColors ? '\u001b[90m' : '';
-      module.exports.clear = hasColors ? '\u001bc' : '';
-      module.exports.hasColors = hasColors;
-    }
+    const isTTY = process.stderr.isTTY;
+    const hasColors = isTTY && module.exports.shouldColorize(process.stderr);
+    ObjectKeys(colorsMap).forEach((key) => {
+      module.exports[key] = hasColors ? colorsMap[key] : '';
+    });
+
+    module.exports.hasColors = hasColors;
   },
 };
 

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)
+[31m(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)[0m

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)
+[31m(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)[0m

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)
+[31m(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)[0m