lib: remove redundant code, add tests in timers.js

insert() is only called from one place where there is already a check
that msecs is greater than or equal to zero, so do not repeat the check
inside insert().

timers.active() is not documented and should not be exposed, but since
it is exposed for now, let's test it.

PR-URL: https://github.com/nodejs/node/pull/3143
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/test/parallel/test-timers-active.js b/test/parallel/test-timers-active.js
new file mode 100644
index 0000000000..9162406848
--- /dev/null
+++ b/test/parallel/test-timers-active.js
@@ -0,0 +1,33 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const active = require('timers').active;
+
+// active() should create timers for these
+var legitTimers = [
+  { _idleTimeout: 0 },
+  { _idleTimeout: 1 }
+];
+
+legitTimers.forEach(function(legit) {
+  const savedTimeout = legit._idleTimeout;
+  active(legit);
+  // active() should mutate these objects
+  assert(legit._idleTimeout === savedTimeout);
+  assert(Number.isInteger(legit._idleStart));
+  assert(legit._idleNext);
+  assert(legit._idlePrev);
+});
+
+
+// active() should not create a timer for these
+var bogusTimers = [
+  { _idleTimeout: -1 }
+];
+
+bogusTimers.forEach(function(bogus) {
+  const savedTimeout = bogus._idleTimeout;
+  active(bogus);
+  // active() should not mutate these objects
+  assert.deepStrictEqual(bogus, {_idleTimeout: savedTimeout});
+});