fix: do not exit when only unref'd timer is present in test code

lib/runnable.js

@@ -16,6 +16,8 @@ var setTimeout = global.setTimeout;
 var clearTimeout = global.clearTimeout;
 var toString = Object.prototype.toString;
 
+var MAX_TIMEOUT = Math.pow(2, 31) - 1;
+
 module.exports = Runnable;
 
 /**
@@ -77,8 +79,7 @@ Runnable.prototype.timeout = function(ms) {
   }
 
   // Clamp to range
-  var INT_MAX = Math.pow(2, 31) - 1;
-  var range = [0, INT_MAX];
+  var range = [0, MAX_TIMEOUT];
   ms = utils.clamp(ms, range);
 
   // see #1652 for reasoning
@@ -253,18 +254,17 @@ Runnable.prototype.inspect = function() {
  */
 Runnable.prototype.resetTimeout = function() {
   var self = this;
-  var ms = this.timeout() || 1e9;
+  // if timeout is 0, _enableTimeouts should also be false.
+  // we set this timeout to MAX_TIMEOUT so the event loop stays active.
+  var ms = this.timeout() || MAX_TIMEOUT;
 
-  if (!this._enableTimeouts) {
-    return;
-  }
   this.clearTimeout();
   this.timer = setTimeout(function() {
-    if (!self._enableTimeouts) {
-      return;
+    // only throw error if timeouts are enabled.
+    if (self._enableTimeouts) {
+      self.callback(self._timeoutError(ms));
+      self.timedOut = true;
     }
-    self.callback(self._timeoutError(ms));
-    self.timedOut = true;
   }, ms);
 };
 

test/integration/fixtures/options/timeout-unref.fixture.js

@@ -0,0 +1,3 @@
+it('unrefs a timeout', function(done) {
+  setTimeout(done, 10).unref();
+});

test/integration/options/timeout.spec.js

@@ -0,0 +1,19 @@
+'use strict';
+
+var helpers = require('../helpers');
+var runMochaJSON = helpers.runMochaJSON;
+
+describe('--timeout', function() {
+  var args = [];
+
+  it("should complete tests having unref'd async behavior", function(done) {
+    args = ['--timeout', '0'];
+    runMochaJSON('options/timeout-unref', args, function(err, res) {
+      if (err) {
+        return done(err);
+      }
+      expect(res, 'to have passed').and('to have passed test count', 1);
+      done();
+    });
+  });
+});