console: add console.count() and console.clear()

Both are simple utility functions defined by the WHATWG
console spec (https://console.spec.whatwg.org/).

PR-URL: https://github.com/nodejs/node/pull/12678
Ref: https://github.com/nodejs/node/issues/12675
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

1 files changed, 63 insertions, 0 deletions

diff --git a/test/parallel/test-console-count.js b/test/parallel/test-console-count.js
new file mode 100644
index 0000000000..64e2641f0a
--- /dev/null
+++ b/test/parallel/test-console-count.js
@@ -0,0 +1,63 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+
+const stdoutWrite = process.stdout.write;
+
+let buf = '';
+
+process.stdout.write = (string) => buf = string;
+
+console.count();
+assert.strictEqual(buf, 'default: 1\n');
+
+// 'default' and undefined are equivalent
+console.count('default');
+assert.strictEqual(buf, 'default: 2\n');
+
+console.count('a');
+assert.strictEqual(buf, 'a: 1\n');
+
+console.count('b');
+assert.strictEqual(buf, 'b: 1\n');
+
+console.count('a');
+assert.strictEqual(buf, 'a: 2\n');
+
+console.count();
+assert.strictEqual(buf, 'default: 3\n');
+
+console.count({});
+assert.strictEqual(buf, '[object Object]: 1\n');
+
+console.count(1);
+assert.strictEqual(buf, '1: 1\n');
+
+console.count(null);
+assert.strictEqual(buf, 'null: 1\n');
+
+console.count('null');
+assert.strictEqual(buf, 'null: 2\n');
+
+console.countReset();
+console.count();
+assert.strictEqual(buf, 'default: 1\n');
+
+console.countReset('a');
+console.count('a');
+assert.strictEqual(buf, 'a: 1\n');
+
+// countReset('a') only reset the a counter
+console.count();
+assert.strictEqual(buf, 'default: 2\n');
+
+process.stdout.write = stdoutWrite;
+
+// Symbol labels do not work
+assert.throws(
+  () => console.count(Symbol('test')),
+  /^TypeError: Cannot convert a Symbol value to a string$/);
+assert.throws(
+  () => console.countReset(Symbol('test')),
+  /^TypeError: Cannot convert a Symbol value to a string$/);