From 636f0028a5333256f556f304a6174d9a7763aa41 Mon Sep 17 00:00:00 2001
From: Bob Zoller <bob@zoller.us>
Date: Mon, 4 May 2015 14:34:19 -0700
Subject: [PATCH] fixes Worker.startTime

closes #38
---
 src/worker.coffee       | 11 ++--------
 test/librato.coffee     |  4 +---
 test/worker.test.coffee | 48 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+), 12 deletions(-)
 create mode 100644 test/worker.test.coffee

diff --git a/src/worker.coffee b/src/worker.coffee
index b5369d9..b89e84a 100644
--- a/src/worker.coffee
+++ b/src/worker.coffee
@@ -28,15 +28,8 @@ class Worker
 
   # Give some structure to worker start times so when possible they will be in sync.
   @startTime: (period) ->
-    earliest = new Date(Date.now() + period)
-    # already on a whole minute
-    return earliest.valueOf() if earliest.getSeconds() is 0
-    if period > 30
-      # bump to whole minute
-      return earliest.valueOf() + (60 - earliest.getSeconds())
-    else
-      # ensure sync to whole minute if minute is evenly divisible
-      return earliest.valueOf() + (period - (earliest.getSeconds() % period))
+    now = Date.now()
+    return now + (period - (now % period))
 
 
 module.exports = Worker
diff --git a/test/librato.coffee b/test/librato.coffee
index c1a33ba..ece3721 100644
--- a/test/librato.coffee
+++ b/test/librato.coffee
@@ -109,7 +109,7 @@ describe 'librato', ->
 
     {clock} = {}
     beforeEach ->
-      clock = sinon.useFakeTimers(new Date().getTime())
+      clock = sinon.useFakeTimers(0)
 
     it 'sends data every 60 seconds', ->
       sinon.stub(librato, 'flush')
@@ -128,5 +128,3 @@ describe 'librato', ->
       clock.tick(4000)
       expect(librato.flush.calledOnce).to.be true
 
-    afterEach ->
-      clock.restore()
diff --git a/test/worker.test.coffee b/test/worker.test.coffee
new file mode 100644
index 0000000..fbc96cd
--- /dev/null
+++ b/test/worker.test.coffee
@@ -0,0 +1,48 @@
+require './support/test_helper'
+Worker = require '../lib/worker'
+
+given_period = (period) ->
+  return {
+    returns: (expected) ->
+      it "given period #{period} returns #{expected}", ->
+        expect(Worker.startTime(period)).to.equal expected
+   }
+
+describe 'Worker', ->
+
+  describe '.startTime', ->
+    {clock, period} = {}
+
+    beforeEach ->
+      clock = sinon.useFakeTimers(0)
+
+    describe 'at 00:00:00', ->
+
+      given_period(60000).returns(60000)
+      given_period(30000).returns(30000)
+      given_period(1000).returns(1000)
+
+    describe 'at 00:00:01', ->
+      beforeEach ->
+        clock.tick 1000
+
+      given_period(60000).returns(60000)
+      given_period(30000).returns(30000)
+      given_period(1000).returns(2000)
+
+    describe 'at 00:00:30', ->
+      beforeEach ->
+        clock.tick 30000
+
+      given_period(60000).returns(60000)
+      given_period(30000).returns(60000)
+      given_period(1000).returns(31000)
+
+    describe 'at 00:01:00.100', ->
+      beforeEach ->
+        clock.tick 60100
+
+      given_period(60000).returns(120000)
+      given_period(30000).returns(90000)
+      given_period(1000).returns(61000)
+