console: delete timers that have ended

Currently, console timers that have been ended with timeEnd()
are not removed. This has the potential to leak memory. This
commit deletes ended timers from the containing Map.

PR-URL: #3562
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Michaël Zasso <mic.besace@gmail.com>

Author: Vladimir Varankin

lib/console.js

@@ -68,6 +68,7 @@ Console.prototype.timeEnd = function(label) {
   const duration = process.hrtime(time);
   const ms = duration[0] * 1000 + duration[1] / 1e6;
   this.log('%s: %sms', label, ms.toFixed(3));
+  this._times.delete(label);
 };
 
 

test/parallel/test-console.js

@@ -57,6 +57,16 @@ console.timeEnd('hasOwnProperty');
 
 global.process.stdout.write = stdout_write;
 
+// verify that console.timeEnd() doesn't leave dead links
+const timesMapSize = console._times.size;
+console.time('label1');
+console.time('label2');
+console.time('label3');
+console.timeEnd('label1');
+console.timeEnd('label2');
+console.timeEnd('label3');
+assert.strictEqual(console._times.size, timesMapSize);
+
 assert.equal('foo\n', strings.shift());
 assert.equal('foo bar\n', strings.shift());
 assert.equal('foo bar hop\n', strings.shift());