console: add support for console.debug

Adds the console.debug() method, alias for console.log(). This method is
exposed by V8 and was only available in inspector until now. Also adds
matching test and documentation.

PR-URL: https://github.com/nodejs/node/pull/17033
Refs: https://github.com/nodejs/node/pull/17004
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Khaidi Chu <i@2333.moe>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/console.md

@@ -238,6 +238,15 @@ undefined
 >
 ```
 
+### console.debug(data[, ...args])
+<!-- YAML
+added: v8.0.0
+-->
+* `data` {any}
+* `...args` {any}
+
+The `console.debug()` function is an alias for [`console.log()`][].
+
 ### console.dir(obj[, options])
 <!-- YAML
 added: v0.1.101

lib/console.js

@@ -134,6 +134,9 @@ Console.prototype.log = function log(...args) {
 };
 
 
+Console.prototype.debug = Console.prototype.log;
+
+
 Console.prototype.info = Console.prototype.log;
 
 

test/parallel/test-console.js

@@ -69,6 +69,13 @@ console.log('%s %s', 'foo', 'bar', 'hop');
 console.log({ slashes: '\\\\' });
 console.log(custom_inspect);
 
+// test console.debug() goes to stdout
+console.debug('foo');
+console.debug('foo', 'bar');
+console.debug('%s %s', 'foo', 'bar', 'hop');
+console.debug({ slashes: '\\\\' });
+console.debug(custom_inspect);
+
 // test console.info() goes to stdout
 console.info('foo');
 console.info('foo', 'bar');
@@ -154,6 +161,10 @@ for (const expected of expectedStrings) {
   assert.strictEqual(errStrings.shift(), `${expected}\n`);
 }
 
+for (const expected of expectedStrings) {
+  assert.strictEqual(strings.shift(), `${expected}\n`);
+}
+
 assert.strictEqual(strings.shift(),
                    "{ foo: 'bar', inspect: [Function: inspect] }\n");
 assert.strictEqual(strings.shift(),