add [homebrew] cask service (#4228)

* add homebrew cask service

* rename formula to cask

services/homebrew/homebrew-cask.service.js

@@ -0,0 +1,48 @@
+'use strict'
+
+const Joi = require('@hapi/joi')
+const { renderVersionBadge } = require('../version')
+const { BaseJsonService } = require('..')
+
+const schema = Joi.object({
+  version: Joi.string().required(),
+}).required()
+
+module.exports = class HomebrewCask extends BaseJsonService {
+  static get category() {
+    return 'version'
+  }
+
+  static get route() {
+    return {
+      base: 'homebrew/cask/v',
+      pattern: ':cask',
+    }
+  }
+
+  static get examples() {
+    return [
+      {
+        title: 'homebrew cask',
+        namedParams: { cask: 'iterm2' },
+        staticPreview: renderVersionBadge({ version: 'v3.2.5' }),
+      },
+    ]
+  }
+
+  static get defaultBadgeData() {
+    return { label: 'homebrew cask' }
+  }
+
+  async fetch({ cask }) {
+    return this._requestJson({
+      schema,
+      url: `https://formulae.brew.sh/api/cask/${cask}.json`,
+    })
+  }
+
+  async handle({ cask }) {
+    const data = await this.fetch({ cask })
+    return renderVersionBadge({ version: data.version })
+  }
+}

services/homebrew/homebrew-cask.tester.js

@@ -0,0 +1,24 @@
+'use strict'
+
+const { isVPlusTripleDottedVersion } = require('../test-validators')
+const t = (module.exports = require('../tester').createServiceTester())
+
+t.create('homebrew cask (valid)')
+  .get('/iterm2.json')
+  .expectBadge({
+    label: 'homebrew cask',
+    message: isVPlusTripleDottedVersion,
+  })
+
+t.create('homebrew cask (valid)')
+  .get('/iterm2.json')
+  .intercept(nock =>
+    nock('https://formulae.brew.sh')
+      .get('/api/cask/iterm2.json')
+      .reply(200, { version: '3.3.6' })
+  )
+  .expectBadge({ label: 'homebrew cask', message: 'v3.3.6' })
+
+t.create('homebrew cask (not found)')
+  .get('/not-a-package.json')
+  .expectBadge({ label: 'homebrew cask', message: 'not found' })