update interval module, add tests

src/helpers/index_interval.js

@@ -1,37 +0,0 @@
-import moment from 'moment';
-
-export const intervals = [
-  'y',
-  'M',
-  'w',
-  'd',
-  'h',
-  'm'
-];
-
-export const intervalNames = [
-  'year',
-  'month',
-  'week',
-  'day',
-  'hour',
-  'minute'
-];
-
-export default function getTimestamp(intervalStr) {
-  const index = intervals.indexOf(intervalStr);
-  if (index === -1) throw new Error('Invalid index interval: ', intervalStr);
-
-  const startType = intervalNames[intervalStr];
-  const m = moment();
-  m.startOf(startType);
-
-  let dateString = 'YYYY-MM-DD';
-  if (startType === 'hour') {
-    dateString += '-HH';
-  }
-  if (startType === 'minute') {
-    dateString += '-HH-mm';
-  }
-  return m.format(dateString);
-}

src/helpers/index_timestamp.js

@@ -0,0 +1,38 @@
+import moment from 'moment';
+
+export const intervals = [
+  'year',
+  'month',
+  'week',
+  'day',
+  'hour',
+  'minute'
+];
+
+export default function indexTimestamp(intervalStr) {
+  const index = intervals.indexOf(intervalStr);
+  if (index === -1) throw new Error('Invalid index interval: ', intervalStr);
+
+  const m = moment();
+  m.startOf(intervalStr);
+
+  let dateString;
+  switch (intervalStr) {
+    case 'year':
+      dateString = 'YYYY';
+      break;
+    case 'month':
+      dateString = 'YYYY-MM';
+      break;
+    case 'hour':
+      dateString = 'YYYY-MM-DD-HH';
+      break;
+    case 'minute':
+      dateString = 'YYYY-MM-DD-HH-mm';
+      break;
+    default:
+      dateString = 'YYYY-MM-DD';
+  }
+
+  return m.format(dateString);
+}

test/src/helpers/index_timestamp.js

@@ -0,0 +1,62 @@
+import expect from 'expect.js';
+import sinon from 'sinon';
+import moment from 'moment';
+import proxyquire from 'proxyquire';
+
+const anchor = '2016-04-02T01:02:03.456'; // saturday
+
+const module = proxyquire.noPreserveCache()('../../../lib/helpers/index_timestamp', {
+  moment: () => moment(anchor)
+});
+const indexTimestamp = module.default;
+
+describe('Index interval', function () {
+  describe('indexTimestamp construction', function () {
+    it('should throw given an invalid interval', function () {
+      const init = () => indexTimestamp('bananas');
+      expect(init).to.throwException(/invalid.+interval/i);
+    });
+  });
+
+  describe('indexTimestamp timestamps', function () {
+    let clock;
+
+    beforeEach(function () {
+      clock = sinon.useFakeTimers(moment(anchor).valueOf());
+    });
+
+    afterEach(function () {
+      clock.restore();
+    });
+
+    it('should return the year', function () {
+      var timestamp = indexTimestamp('year');
+      expect(timestamp).to.equal('2016');
+    });
+
+    it('should return the year and month', function () {
+      var timestamp = indexTimestamp('month');
+      expect(timestamp).to.equal('2016-04');
+    });
+
+    it('should return the year, month, and first day of the week', function () {
+      var timestamp = indexTimestamp('week');
+      expect(timestamp).to.equal('2016-03-27');
+    });
+
+    it('should return the year, month, and day of the week', function () {
+      var timestamp = indexTimestamp('day');
+      expect(timestamp).to.equal('2016-04-02');
+    });
+
+    it('should return the year, month, day and hour', function () {
+      var timestamp = indexTimestamp('hour');
+      expect(timestamp).to.equal('2016-04-02-01');
+    });
+
+    it('should return the year, month, day, hour and minute', function () {
+      var timestamp = indexTimestamp('minute');
+      expect(timestamp).to.equal('2016-04-02-01-02');
+    });
+  });
+});