replace [twitter] badge with static fallback

services/twitter/twitter.service.js

@@ -1,7 +1,6 @@
 import Joi from 'joi'
-import { metric } from '../text-formatters.js'
 import { optionalUrl } from '../validators.js'
-import { BaseService, BaseJsonService, NotFound } from '../index.js'
+import { BaseService, BaseJsonService } from '../index.js'
 
 const queryParamSchema = Joi.object({
   url: optionalUrl.required(),
@@ -33,6 +32,8 @@ class TwitterUrl extends BaseService {
     },
   ]
 
+  static _cacheLength = 86400
+
   static defaultBadgeData = {
     namedLogo: 'twitter',
   }
@@ -51,8 +52,19 @@ class TwitterUrl extends BaseService {
   }
 }
 
-const schema = Joi.any()
+/*
+This badge is unusual.
+
+We don't usually host badges that don't show any dynamic information.
+Also when an upstream API is removed, we usually deprecate/remove badges
+according to the process in
+https://github.com/badges/shields/blob/master/doc/deprecating-badges.md
 
+In the case of twitter, we decided to provide a static fallback instead
+due to how widely used the badge was. See
+https://github.com/badges/shields/issues/8837
+for related discussion.
+*/
 class TwitterFollow extends BaseJsonService {
   static category = 'social'
 
@@ -65,51 +77,40 @@ class TwitterFollow extends BaseJsonService {
     {
       title: 'Twitter Follow',
       namedParams: {
-        user: 'espadrine',
+        user: 'shields_io',
       },
       queryParams: { label: 'Follow' },
       // hard code the static preview
       // because link[] is not allowed in examples
       staticPreview: {
-        label: 'Follow',
-        message: '393',
+        label: 'Follow @shields_io',
+        message: '',
         style: 'social',
       },
     },
   ]
 
+  static _cacheLength = 86400
+
   static defaultBadgeData = {
     namedLogo: 'twitter',
   }
 
-  static render({ user, followers }) {
+  static render({ user }) {
     return {
       label: `follow @${user}`,
-      message: metric(followers),
+      message: '',
       style: 'social',
       link: [
         `https://twitter.com/intent/follow?screen_name=${encodeURIComponent(
           user
         )}`,
-        `https://twitter.com/${encodeURIComponent(user)}/followers`,
       ],
     }
   }
 
-  async fetch({ user }) {
-    return this._requestJson({
-      schema,
-      url: 'http://cdn.syndication.twimg.com/widgets/followbutton/info.json',
-      options: { searchParams: { screen_names: user } },
-    })
-  }
-
   async handle({ user }) {
-    const data = await this.fetch({ user })
-    if (!Array.isArray(data) || data.length === 0) {
-      throw new NotFound({ prettyMessage: 'invalid user' })
-    }
-    return this.constructor.render({ user, followers: data[0].followers_count })
+    return this.constructor.render({ user })
   }
 }
 

services/twitter/twitter.tester.js

@@ -1,4 +1,3 @@
-import { isMetric } from '../test-validators.js'
 import { ServiceTester } from '../tester.js'
 
 export const t = new ServiceTester({
@@ -10,25 +9,8 @@ t.create('Followers')
   .get('/follow/shields_io.json')
   .expectBadge({
     label: 'follow @shields_io',
-    message: isMetric,
-    link: [
-      'https://twitter.com/intent/follow?screen_name=shields_io',
-      'https://twitter.com/shields_io/followers',
-    ],
-  })
-
-t.create('Invalid Username Specified (non-existent user)')
-  .get('/follow/invalidusernamethatshouldnotexist.json?label=Follow')
-  .expectBadge({
-    label: 'Follow',
-    message: 'invalid user',
-  })
-
-t.create('Invalid Username Specified (only spaces)')
-  .get('/follow/%20%20.json?label=Follow')
-  .expectBadge({
-    label: 'Follow',
-    message: 'invalid user',
+    message: '',
+    link: ['https://twitter.com/intent/follow?screen_name=shields_io'],
   })
 
 t.create('URL')