Move service tests alongside code (#1563)

Per discussion in #1543

services/bundlephobia/bundlephobia.tester.js

@@ -0,0 +1,78 @@
+'use strict'
+
+const Joi = require('joi')
+const ServiceTester = require('../service-tester')
+const { isFileSize } = require('../test-validators')
+
+const t = new ServiceTester({
+  id: 'bundlephobia', title: 'NPM package bundle size',
+})
+
+module.exports = t
+
+const formats = {
+  A: '/bundlephobia/:type/:package.:format',
+  B: '/bundlephobia/:type/:package/:version.:format',
+  C: '/bundlephobia/:type/@:scope/:package.:format',
+  D: '/bundlephobia/:type/@:scope/:package/:version.:format',
+}
+
+const data = [
+  {
+    format: formats.A,
+    get: '/min/preact.json',
+    expect: { name: 'minified size', value: isFileSize },
+  },
+  {
+    format: formats.B,
+    get: '/min/preact/8.0.0.json',
+    expect: { name: 'minified size', value: '7.94 kB' },
+  },
+  {
+    format: formats.C,
+    get: '/min/@cycle/core.json',
+    expect: { name: 'minified size', value: isFileSize },
+  },
+  {
+    format: formats.D,
+    get: '/min/@cycle/core/7.0.0.json',
+    expect: { name: 'minified size', value: '3.51 kB' },
+  },
+  {
+    format: formats.A,
+    get: '/minzip/preact.json',
+    expect: { name: 'minzipped size', value: isFileSize },
+  },
+  {
+    format: formats.B,
+    get: '/minzip/preact/8.0.0.json',
+    expect: { name: 'minzipped size', value: '3.35 kB' },
+  },
+  {
+    format: formats.C,
+    get: '/minzip/@cycle/core.json',
+    expect: { name: 'minzipped size', value: isFileSize },
+  },
+  {
+    format: formats.D,
+    get: '/minzip/@cycle/core/7.0.0.json',
+    expect: { name: 'minzipped size', value: '1.23 kB' },
+  },
+  {
+    format: formats.A,
+    get: '/min/some-no-exist.json',
+    expect: { name: 'minified size', value: 'package not found error' },
+  },
+  {
+    format: formats.C,
+    get: '/min/@some-no-exist/some-no-exist.json',
+    expect: { name: 'minified size', value: 'package not found error' },
+  }
+]
+
+data.forEach( ({format, get, expect }) => {
+  t.create(`Testing format '${format}' against '${get}'`)
+    .get(get)
+    .expectJSONTypes(Joi.object().keys(expect))
+  }
+)