chore: add tests

.eslintrc.js

@@ -13,8 +13,10 @@ module.exports = {
       files: 'test/**/*.+(t|j)s',
       rules: {
         'no-magic-numbers': 'off',
+        'no-undef': 'off',
         'promise/prefer-await-to-callbacks': 'off',
         'unicorn/filename-case': 'off',
+        'unicorn/consistent-function-scoping': 'off',
       },
     },
   ],

test/helpers/mock_fetch.js

@@ -0,0 +1,74 @@
+const assert = require('assert')
+
+module.exports = class MockFetch {
+  constructor() {
+    this.requests = []
+  }
+
+  addExpectedRequest({ body, headers = {}, method, response, url }) {
+    this.requests.push({ body, fulfilled: false, headers, method, response, url })
+
+    return this
+  }
+
+  delete(options) {
+    return this.addExpectedRequest({ ...options, method: 'delete' })
+  }
+
+  get(options) {
+    return this.addExpectedRequest({ ...options, method: 'get' })
+  }
+
+  post(options) {
+    return this.addExpectedRequest({ ...options, method: 'post' })
+  }
+
+  put(options) {
+    return this.addExpectedRequest({ ...options, method: 'put' })
+  }
+
+  get fetcher() {
+    // eslint-disable-next-line require-await
+    return async (...args) => {
+      const [url, options] = args
+      const headers = options?.headers
+      const urlString = url.toString()
+      const match = this.requests.find(
+        (request) =>
+          request.method.toLowerCase() === options?.method.toLowerCase() &&
+          request.url === urlString &&
+          !request.fulfilled,
+      )
+
+      if (!match) {
+        throw new Error(`Unexpected fetch call: ${url}`)
+      }
+
+      for (const key in match.headers) {
+        assert.equal(headers[key], match.headers[key])
+      }
+
+      if (typeof match.body === 'string') {
+        assert.equal(options?.body, match.body)
+      } else if (typeof match.body === 'function') {
+        const bodyFn = match.body
+
+        bodyFn(options?.body)
+      } else {
+        assert.equal(options?.body, undefined)
+      }
+
+      match.fulfilled = true
+
+      if (match.response instanceof Error) {
+        throw match.response
+      }
+
+      return match.response
+    }
+  }
+
+  get fulfilled() {
+    return this.requests.every((request) => request.fulfilled)
+  }
+}

test/types/Handler.test-d.ts

@@ -4,7 +4,7 @@ import { Handler } from '../../src/main.js'
 
 // Ensure void is NOT a valid return type in async handlers
 expectError(() => {
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars, unicorn/consistent-function-scoping
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const handler: Handler = async () => {
     // void
   }

test/unit/purge_cache.js

@@ -0,0 +1,78 @@
+const process = require('process')
+
+const test = require('ava')
+
+const { purgeCache } = require('../../dist/lib/purge_cache')
+const { invokeLambda } = require('../helpers/main')
+const MockFetch = require('../helpers/mock_fetch')
+
+const globalFetch = globalThis.fetch
+
+test.beforeEach(() => {
+  delete process.env.NETLIFY_PURGE_API_TOKEN
+  delete process.env.SITE_ID
+})
+
+test.afterEach(() => {
+  globalThis.fetch = globalFetch
+})
+
+test.serial('Calls the purge API endpoint and returns `undefined` if the operation was successful', async (t) => {
+  const mockSiteID = '123456789'
+  const mockToken = '1q2w3e4r5t6y7u8i9o0p'
+
+  process.env.NETLIFY_PURGE_API_TOKEN = mockToken
+  process.env.SITE_ID = mockSiteID
+
+  const mockAPI = new MockFetch().post({
+    body: (payload) => {
+      const data = JSON.parse(payload)
+
+      t.is(data.site_id, mockSiteID)
+    },
+    headers: { Authorization: `Bearer ${mockToken}` },
+    method: 'post',
+    response: new Response(null, { status: 202 }),
+    url: `https://api.netlify.com/api/v1/purge`,
+  })
+  const myFunction = async () => {
+    await purgeCache()
+  }
+
+  globalThis.fetch = mockAPI.fetcher
+
+  const response = await invokeLambda(myFunction)
+
+  t.is(response, undefined)
+  t.true(mockAPI.fulfilled)
+})
+
+test.serial('Throws if the API response does not have a successful status code', async (t) => {
+  const mockSiteID = '123456789'
+  const mockToken = '1q2w3e4r5t6y7u8i9o0p'
+
+  process.env.NETLIFY_PURGE_API_TOKEN = mockToken
+  process.env.SITE_ID = mockSiteID
+
+  const mockAPI = new MockFetch().post({
+    body: (payload) => {
+      const data = JSON.parse(payload)
+
+      t.is(data.site_id, mockSiteID)
+    },
+    headers: { Authorization: `Bearer ${mockToken}` },
+    method: 'post',
+    response: new Response(null, { status: 500 }),
+    url: `https://api.netlify.com/api/v1/purge`,
+  })
+  const myFunction = async () => {
+    await purgeCache()
+  }
+
+  globalThis.fetch = mockAPI.fetcher
+
+  await t.throwsAsync(
+    async () => await invokeLambda(myFunction),
+    'Cache purge API call returned an unexpected status code: 500',
+  )
+})