Add [Repology] repositories badge (#4529)

* Add [Repology] repositories badge

Partly addresses #929

* Replace JSON API with SVG scrape

* Fix failing tests

* Replace Joi.number with nonNegativeInteger

* Replace integer with string in failing test

* Update title to specify that the badge is for num of repositories

* Remove repology-repositories.spec.js

* Remove keywords

* Use the metric text formatter

* Remove mocked svg test

* Remove the "in" preposition

services/repology/repology-repositories.service.js

@@ -0,0 +1,55 @@
+'use strict'
+
+const Joi = require('@hapi/joi')
+const { metric } = require('../text-formatters')
+const { nonNegativeInteger } = require('../validators')
+const { BaseSvgScrapingService } = require('..')
+
+const schema = Joi.object({
+  message: nonNegativeInteger,
+}).required()
+
+module.exports = class RepologyRepositories extends BaseSvgScrapingService {
+  static get category() {
+    return 'platform-support'
+  }
+
+  static get route() {
+    return {
+      base: 'repology/repositories',
+      pattern: ':projectName',
+    }
+  }
+
+  static get examples() {
+    return [
+      {
+        title: 'Repology - Repositories',
+        namedParams: { projectName: 'starship' },
+        staticPreview: this.render({ repositoryCount: '18' }),
+      },
+    ]
+  }
+
+  static get defaultBadgeData() {
+    return {
+      label: 'repositories',
+      color: 'blue',
+    }
+  }
+
+  static render({ repositoryCount }) {
+    return {
+      message: metric(repositoryCount),
+    }
+  }
+
+  async handle({ projectName }) {
+    const { message: repositoryCount } = await this._requestSvg({
+      schema,
+      url: `https://repology.org/badge/tiny-repos/${projectName}.svg`,
+    })
+
+    return this.constructor.render({ repositoryCount })
+  }
+}

services/repology/repology-repositories.tester.js

@@ -0,0 +1,18 @@
+'use strict'
+
+const t = (module.exports = require('../tester').createServiceTester())
+const { nonNegativeInteger } = require('../validators')
+
+t.create('Existing project')
+  .get('/starship.json')
+  .expectBadge({
+    label: 'repositories',
+    message: nonNegativeInteger,
+  })
+
+t.create('Non-existent project')
+  .get('/invalidprojectthatshouldnotexist.json')
+  .expectBadge({
+    label: 'repositories',
+    message: '0',
+  })