Add [StackExchange] monthly questions badge service (#2432)

- Badge shows number of questions for a given library for the previous month (not current month because its in progress)
- Service works for not just the StackOverflow site but for other StackExchange sites also

Close #2378

services/stackexchange/stackexchange-helpers.js

@@ -0,0 +1,18 @@
+'use strict'
+
+const { metric } = require('../../lib/text-formatters')
+const { floorCount: floorCountColor } = require('../../lib/color-formatters')
+
+module.exports = function renderQuestionsBadge({
+  suffix,
+  stackexchangesite,
+  query,
+  numValue,
+}) {
+  const label = `${stackexchangesite} ${query} questions`
+  return {
+    label,
+    message: `${metric(numValue)}${suffix}`,
+    color: floorCountColor(numValue, 1000, 10000, 20000),
+  }
+}

services/stackexchange/stackexchange-monthlyquestions.service.js

@@ -0,0 +1,86 @@
+'use strict'
+
+const BaseJsonService = require('../base-json')
+const renderQuestionsBadge = require('./stackexchange-helpers')
+const moment = require('moment')
+const Joi = require('joi')
+
+const tagSchema = Joi.object({
+  total: Joi.number()
+    .min(1)
+    .required(),
+}).required()
+
+module.exports = class StackExchangeMonthlyQuestions extends BaseJsonService {
+  static get category() {
+    return 'other'
+  }
+
+  static get defaultBadgeData() {
+    return { label: 'stackoverflow' }
+  }
+
+  static get examples() {
+    return [
+      {
+        title: 'Stack Exchange monthly questions',
+        namedParams: { stackexchangesite: 'stackoverflow', query: 'momentjs' },
+        staticExample: this.render({
+          stackexchangesite: 'stackoverflow',
+          query: 'momentjs',
+          numValue: 2000,
+        }),
+        keywords: ['stackexchange', 'stackoverflow'],
+      },
+    ]
+  }
+
+  static get route() {
+    return {
+      base: 'stackexchange',
+      pattern: ':stackexchangesite/qm/:query',
+    }
+  }
+
+  static render(props) {
+    return renderQuestionsBadge({
+      suffix: '/month',
+      ...props,
+    })
+  }
+
+  async handle({ stackexchangesite, query }) {
+    const today = moment().toDate()
+    const prevMonthStart = moment(today)
+      .subtract(1, 'months')
+      .startOf('month')
+      .unix()
+    const prevMonthEnd = moment(today)
+      .subtract(1, 'months')
+      .endOf('month')
+      .unix()
+
+    const parsedData = await this._requestJson({
+      schema: tagSchema,
+      options: {
+        gzip: true,
+        qs: {
+          site: stackexchangesite,
+          fromdate: prevMonthStart,
+          todate: prevMonthEnd,
+          filter: 'total',
+          tagged: query,
+        },
+      },
+      url: `https://api.stackexchange.com/2.2/questions`,
+    })
+
+    const numValue = parsedData.total
+
+    return this.constructor.render({
+      stackexchangesite,
+      query,
+      numValue,
+    })
+  }
+}

services/stackexchange/stackexchange-monthlyquestions.tester.js

@@ -0,0 +1,24 @@
+'use strict'
+
+const Joi = require('joi')
+const { isMetricOverTimePeriod } = require('../test-validators')
+const t = require('../create-service-tester')()
+module.exports = t
+
+t.create('Monthly Questions for StackOverflow Momentjs')
+  .get('/stackoverflow/qm/momentjs.json')
+  .expectJSONTypes(
+    Joi.object().keys({
+      name: 'stackoverflow momentjs questions',
+      value: isMetricOverTimePeriod,
+    })
+  )
+
+t.create('Monthly Questions for Tex Spacing')
+  .get('/tex/qm/spacing.json')
+  .expectJSONTypes(
+    Joi.object().keys({
+      name: 'tex spacing questions',
+      value: isMetricOverTimePeriod,
+    })
+  )

services/stackexchange/stackexchange-taginfo.service.js

@@ -1,8 +1,7 @@
 'use strict'
 
 const BaseJsonService = require('../base-json')
-const { metric } = require('../../lib/text-formatters')
-const { floorCount: floorCountColor } = require('../../lib/color-formatters')
+const renderQuestionsBadge = require('./stackexchange-helpers')
 const Joi = require('joi')
 
 const tagSchema = Joi.object({
@@ -49,14 +48,11 @@ module.exports = class StackExchangeQuestions extends BaseJsonService {
     }
   }
 
-  static render({ stackexchangesite, query, numValue }) {
-    const label = `${stackexchangesite} ${query} questions`
-
-    return {
-      label,
-      message: metric(numValue),
-      color: floorCountColor(numValue, 1000, 10000, 20000),
-    }
+  static render(props) {
+    return renderQuestionsBadge({
+      suffix: '',
+      ...props,
+    })
   }
 
   async handle({ stackexchangesite, query }) {