Add metric column component

- This ensures that we render numeric values only
The component renders a dash for non-numeric and null values

ee/app/assets/javascripts/analytics/productivity_analytics/components/metric_column.vue

+<script>
+import { n__ } from '~/locale';
+
+export default {
+  props: {
+    type: {
+      type: String,
+      required: true,
+    },
+    /**
+     * With default null we will render a "-" in the last column as opposed to a numeric value
+     */
+    value: {
+      type: Number,
+      required: false,
+      default: null,
+    },
+    label: {
+      type: String,
+      required: false,
+      default: '',
+    },
+  },
+  computed: {
+    isNumericValue() {
+      return this.value !== null && !Number.isNaN(Number(this.value));
+    },
+    unit() {
+      return this.type === 'days_to_merge'
+        ? n__('day', 'days', this.value)
+        : n__('Time|hr', 'Time|hrs', this.value);
+    },
+  },
+};
+</script>
+<template>
+  <div class="metric-col">
+    <span class="time">
+      <template v-if="isNumericValue">
+        {{ value }}
+        <span> {{ unit }} </span>
+      </template>
+      <template v-else>
+        &ndash;
+      </template>
+    </span>
+    <span v-if="label" class="d-flex d-md-none text-secondary metric-label">{{ label }}</span>
+  </div>
+</template>

ee/app/assets/javascripts/analytics/productivity_analytics/components/mr_table_row.vue

 <script>
 import { sprintf, __, n__ } from '~/locale';
 import { GlLink, GlAvatar } from '@gitlab/ui';
+import MetricColumn from './metric_column.vue';
 
 export default {
   components: {
     GlLink,
     GlAvatar,
+    MetricColumn,
   },
   props: {
     mergeRequest: {
@@ -68,20 +70,12 @@ export default {
       </div>
     </div>
     <div class="table-section section-50 d-flex flex-row align-items-start qa-mr-metrics">
-      <div class="metric-col">
-        <span class="time">
-          {{ mergeRequest.time_to_merge }}
-          <span> {{ n__('Time|hr', 'Time|hrs', mergeRequest.time_to_merge) }} </span>
-        </span>
-        <span class="d-flex d-md-none text-secondary metric-label">{{ __('Time to merge') }}</span>
-      </div>
-      <div class="metric-col">
-        <span class="time">
-          {{ selectedMetric }}
-          <span> {{ metricTimeUnit }} </span>
-        </span>
-        <span class="d-flex d-md-none text-secondary metric-label">{{ metricLabel }}</span>
-      </div>
+      <metric-column
+        type="time_to_merge"
+        :value="mergeRequest.time_to_merge"
+        :label="__('Time to merge')"
+      />
+      <metric-column :type="metricType" :value="selectedMetric" :label="metricLabel" />
     </div>
   </div>
 </template>

ee/spec/frontend/analytics/productivity_analytics/components/__snapshots__/metric_column_spec.js.snap

+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`MetricColumn component on creation matches the snapshot 1`] = `
+<div
+  class="metric-col"
+>
+  <span
+    class="time"
+  >
+    
+      10
+      
+    <span>
+       hrs 
+    </span>
+  </span>
+   
+  <span
+    class="d-flex d-md-none text-secondary metric-label"
+  >
+    Time from first comment to last commit
+  </span>
+</div>
+`;

ee/spec/frontend/analytics/productivity_analytics/components/__snapshots__/mr_table_row_spec.js.snap

@@ -58,47 +58,17 @@ exports[`MergeRequestTableRow component on creation matches the snapshot 1`] = `
   <div
     class="table-section section-50 d-flex flex-row align-items-start qa-mr-metrics"
   >
-    <div
-      class="metric-col"
-    >
-      <span
-        class="time"
-      >
-        
-        0
-        
-        <span>
-           hrs 
-        </span>
-      </span>
-       
-      <span
-        class="d-flex d-md-none text-secondary metric-label"
-      >
-        Time to merge
-      </span>
-    </div>
+    <metriccolumn-stub
+      label="Time to merge"
+      type="time_to_merge"
+      value="0"
+    />
      
-    <div
-      class="metric-col"
-    >
-      <span
-        class="time"
-      >
-        
-        0
-        
-        <span>
-           hrs 
-        </span>
-      </span>
-       
-      <span
-        class="d-flex d-md-none text-secondary metric-label"
-      >
-        Time from first comment to last commit
-      </span>
-    </div>
+    <metriccolumn-stub
+      label="Time from first comment to last commit"
+      type="time_to_last_commit"
+      value="0"
+    />
   </div>
 </div>
 `;

ee/spec/frontend/analytics/productivity_analytics/components/metric_column_spec.js

+import { createLocalVue, shallowMount } from '@vue/test-utils';
+import MetricColumn from 'ee/analytics/productivity_analytics/components/metric_column.vue';
+
+describe('MetricColumn component', () => {
+  let wrapper;
+
+  const defaultProps = {
+    type: 'time_to_last_commit',
+    value: 10,
+    label: 'Time from first comment to last commit',
+  };
+
+  const factory = (props = defaultProps) => {
+    const localVue = createLocalVue();
+
+    wrapper = shallowMount(localVue.extend(MetricColumn), {
+      localVue,
+      sync: false,
+      propsData: { ...props },
+    });
+  };
+
+  afterEach(() => {
+    wrapper.destroy();
+  });
+
+  const findTimeContainer = () => wrapper.find('.time');
+
+  describe('on creation', () => {
+    beforeEach(() => {
+      factory();
+    });
+
+    it('matches the snapshot', () => {
+      expect(wrapper.element).toMatchSnapshot();
+    });
+  });
+
+  describe('template', () => {
+    describe('when metric has value', () => {
+      beforeEach(() => {
+        factory();
+      });
+
+      it('renders the value and unit', () => {
+        const unit = 'hrs';
+        expect(findTimeContainer().text()).toContain(`${defaultProps.value}`);
+        expect(findTimeContainer().text()).toContain(unit);
+      });
+    });
+
+    describe('when metric has no value', () => {
+      beforeEach(() => {
+        factory({
+          ...defaultProps,
+          value: null,
+        });
+      });
+
+      it('renders a dash', () => {
+        expect(findTimeContainer().text()).toContain('–');
+      });
+    });
+  });
+
+  describe('computed', () => {
+    describe('isNumericValue', () => {
+      it('returns true when the value is neither null nor undefined', () => {
+        factory();
+        expect(wrapper.vm.isNumericValue).toBe(true);
+      });
+
+      it('returns false when the value is null', () => {
+        factory({
+          ...defaultProps,
+          value: null,
+        });
+        expect(wrapper.vm.isNumericValue).toBe(false);
+      });
+    });
+
+    describe('unit', () => {
+      it('returns "days" for the "days_to_merge" metric', () => {
+        factory({
+          ...defaultProps,
+          type: 'days_to_merge',
+        });
+
+        expect(wrapper.vm.unit).toBe('days');
+      });
+
+      it('returns "hrs" for the any other metric', () => {
+        factory({
+          ...defaultProps,
+        });
+
+        expect(wrapper.vm.unit).toBe('hrs');
+      });
+    });
+  });
+});

ee/spec/frontend/analytics/productivity_analytics/components/mr_table_row_spec.js

 import { createLocalVue, shallowMount } from '@vue/test-utils';
 import MergeRequestTableRow from 'ee/analytics/productivity_analytics/components/mr_table_row.vue';
+import MetricColumn from 'ee/analytics/productivity_analytics/components/metric_column.vue';
 import { GlAvatar } from '@gitlab/ui';
 import { mockMergeRequests } from '../mock_data';
 
@@ -24,7 +25,7 @@ describe('MergeRequestTableRow component', () => {
 
   const findMrDetails = () => wrapper.find('.qa-mr-details');
   const findMrMetrics = () => wrapper.find('.qa-mr-metrics');
-  const findMetricColumns = () => findMrMetrics().findAll('.metric-col');
+  const findMetricColumns = () => findMrMetrics().findAll(MetricColumn);
 
   afterEach(() => {
     wrapper.destroy();
@@ -68,8 +69,8 @@ describe('MergeRequestTableRow component', () => {
         expect(
           findMetricColumns()
             .at(0)
-            .text(),
-        ).toContain(defaultProps.mergeRequest.time_to_merge);
+            .props('value'),
+        ).toBe(defaultProps.mergeRequest.time_to_merge);
       });
     });
   });