Merge branch 'winh-countdown-component' into 'master'

Add reusable component for counting down

See merge request gitlab-org/gitlab-ce!22499

4 files changed, 156 insertions, 0 deletions

diff --git a/app/assets/javascripts/lib/utils/datetime_utility.js b/app/assets/javascripts/lib/utils/datetime_utility.js
index 1bdf98d0c97..46740308f17 100644
--- a/app/assets/javascripts/lib/utils/datetime_utility.js
+++ b/app/assets/javascripts/lib/utils/datetime_utility.js
@@ -473,3 +473,15 @@ export const stringifyTime = timeObject => {
  */
 export const abbreviateTime = timeStr =>
   timeStr.split(' ').filter(unitStr => unitStr.charAt(0) !== '0')[0];
+
+/**
+ * Calculates the milliseconds between now and a given date string.
+ * The result cannot become negative.
+ *
+ * @param endDate date string that the time difference is calculated for
+ * @return {number} number of milliseconds remaining until the given date
+ */
+export const calculateRemainingMilliseconds = endDate => {
+  const remainingMilliseconds = new Date(endDate).getTime() - Date.now();
+  return Math.max(remainingMilliseconds, 0);
+};
diff --git a/app/assets/javascripts/vue_shared/components/gl_countdown.vue b/app/assets/javascripts/vue_shared/components/gl_countdown.vue
new file mode 100644
index 00000000000..9327a2a4a6c
--- /dev/null
+++ b/app/assets/javascripts/vue_shared/components/gl_countdown.vue
@@ -0,0 +1,49 @@
+<script>
+import { calculateRemainingMilliseconds, formatTime } from '~/lib/utils/datetime_utility';
+
+/**
+ * Counts down to a given end date.
+ */
+export default {
+  props: {
+    endDateString: {
+      type: String,
+      required: true,
+      validator(value) {
+        return !Number.isNaN(new Date(value).getTime());
+      },
+    },
+  },
+
+  data() {
+    return {
+      remainingTime: formatTime(0),
+      countdownUpdateIntervalId: null,
+    };
+  },
+
+  mounted() {
+    const updateRemainingTime = () => {
+      const remainingMilliseconds = calculateRemainingMilliseconds(this.endDateString);
+      this.remainingTime = formatTime(remainingMilliseconds);
+    };
+
+    updateRemainingTime();
+    this.countdownUpdateIntervalId = window.setInterval(updateRemainingTime, 1000);
+  },
+
+  beforeDestroy() {
+    window.clearInterval(this.countdownUpdateIntervalId);
+  },
+};
+</script>
+
+<template>
+  <time
+    v-gl-tooltip
+    :datetime="endDateString"
+    :title="endDateString"
+  >
+    {{ remainingTime }}
+  </time>
+</template>
diff --git a/spec/javascripts/datetime_utility_spec.js b/spec/javascripts/lib/utils/datetime_utility_spec.js
index 2821f4d6793..de6b96aab57 100644
--- a/spec/javascripts/datetime_utility_spec.js
+++ b/spec/javascripts/lib/utils/datetime_utility_spec.js
@@ -352,3 +352,21 @@ describe('prettyTime methods', () => {
     });
   });
 });
+
+describe('calculateRemainingMilliseconds', () => {
+  beforeEach(() => {
+    spyOn(Date, 'now').and.callFake(() => new Date('2063-04-04T00:42:00Z').getTime());
+  });
+
+  it('calculates the remaining time for a given end date', () => {
+    const milliseconds = datetimeUtility.calculateRemainingMilliseconds('2063-04-04T01:44:03Z');
+
+    expect(milliseconds).toBe(3723000);
+  });
+
+  it('returns 0 if the end date has passed', () => {
+    const milliseconds = datetimeUtility.calculateRemainingMilliseconds('2063-04-03T00:00:00Z');
+
+    expect(milliseconds).toBe(0);
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/gl_countdown_spec.js b/spec/javascripts/vue_shared/components/gl_countdown_spec.js
new file mode 100644
index 00000000000..929ffe219f4
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/gl_countdown_spec.js
@@ -0,0 +1,77 @@
+import mountComponent from 'spec/helpers/vue_mount_component_helper';
+import Vue from 'vue';
+import GlCountdown from '~/vue_shared/components/gl_countdown.vue';
+
+describe('GlCountdown', () => {
+  const Component = Vue.extend(GlCountdown);
+  let vm;
+  let now = '2000-01-01T00:00:00Z';
+
+  beforeEach(() => {
+    spyOn(Date, 'now').and.callFake(() => new Date(now).getTime());
+    jasmine.clock().install();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+    jasmine.clock().uninstall();
+  });
+
+  describe('when there is time remaining', () => {
+    beforeEach(done => {
+      vm = mountComponent(Component, {
+        endDateString: '2000-01-01T01:02:03Z',
+      });
+
+      Vue.nextTick()
+        .then(done)
+        .catch(done.fail);
+    });
+
+    it('displays remaining time', () => {
+      expect(vm.$el).toContainText('01:02:03');
+    });
+
+    it('updates remaining time', done => {
+      now = '2000-01-01T00:00:01Z';
+      jasmine.clock().tick(1000);
+
+      Vue.nextTick()
+        .then(() => {
+          expect(vm.$el).toContainText('01:02:02');
+          done();
+        })
+        .catch(done.fail);
+    });
+  });
+
+  describe('when there is no time remaining', () => {
+    beforeEach(done => {
+      vm = mountComponent(Component, {
+        endDateString: '1900-01-01T00:00:00Z',
+      });
+
+      Vue.nextTick()
+        .then(done)
+        .catch(done.fail);
+    });
+
+    it('displays 00:00:00', () => {
+      expect(vm.$el).toContainText('00:00:00');
+    });
+  });
+
+  describe('when an invalid date is passed', () => {
+    it('throws a validation error', () => {
+      spyOn(Vue.config, 'warnHandler').and.stub();
+      vm = mountComponent(Component, {
+        endDateString: 'this is invalid',
+      });
+
+      expect(Vue.config.warnHandler).toHaveBeenCalledTimes(1);
+      const [errorMessage] = Vue.config.warnHandler.calls.argsFor(0);
+
+      expect(errorMessage).toMatch(/^Invalid prop: .* "endDateString"/);
+    });
+  });
+});