fix(command-dev): handle event triggered background functions (#2704)

src/commands/functions/invoke.js

@@ -8,11 +8,11 @@ const inquirer = require('inquirer')
 const fetch = require('node-fetch')
 
 const Command = require('../../utils/command')
-const { getFunctions } = require('../../utils/get-functions')
+const { getFunctions, BACKGROUND } = require('../../utils/get-functions')
 const { NETLIFYDEVWARN } = require('../../utils/logo')
 
 // https://www.netlify.com/docs/functions/#event-triggered-functions
-const eventTriggeredFunctions = new Set([
+const events = [
   'deploy-building',
   'deploy-succeeded',
   'deploy-failed',
@@ -25,7 +25,8 @@ const eventTriggeredFunctions = new Set([
   'identity-validate',
   'identity-signup',
   'identity-login',
-])
+]
+const eventTriggeredFunctions = new Set([...events, ...events.map((name) => `${name}${BACKGROUND}`)])
 
 const DEFAULT_PORT = 8888
 

src/utils/get-functions.js

@@ -44,4 +44,4 @@ const getFunctionsAndWatchDirs = async (functionsSrcDir) => {
   return { functions: functionsWithProps, watchDirs }
 }
 
-module.exports = { getFunctions, getFunctionsAndWatchDirs }
+module.exports = { getFunctions, getFunctionsAndWatchDirs, BACKGROUND }

src/utils/serve-functions.js

@@ -21,7 +21,7 @@ const winston = require('winston')
 const { getLogMessage } = require('../lib/log')
 
 const { detectFunctionsBuilder } = require('./detect-functions-builder')
-const { getFunctionsAndWatchDirs } = require('./get-functions')
+const { getFunctionsAndWatchDirs, BACKGROUND } = require('./get-functions')
 const { NETLIFYDEVLOG, NETLIFYDEVERR } = require('./logo')
 
 const formatLambdaLocalError = (err) => `${err.errorType}: ${err.errorMessage}\n  ${err.stackTrace.join('\n  ')}`
@@ -322,7 +322,25 @@ const setupDefaultFunctionHandler = async ({ capabilities, directory, warn }) =>
   return { getFunctionByName }
 }
 
-const createFormSubmissionHandler = function ({ siteUrl, warn }) {
+const getFormHandler = function ({ getFunctionByName, warn }) {
+  const handlers = ['submission-created', `submission-created${BACKGROUND}`]
+    .map((name) => getFunctionByName(name))
+    .filter(Boolean)
+    .map(({ name }) => name)
+
+  if (handlers.length === 0) {
+    warn(`Missing form submission function handler`)
+    return
+  }
+
+  if (handlers.length === 2) {
+    warn(`Detected both '${handlers[0]}' and '${handlers[1]}' form submission functions handlers, using ${handlers[0]}`)
+  }
+
+  return handlers[0]
+}
+
+const createFormSubmissionHandler = function ({ getFunctionByName, siteUrl, warn }) {
   return async function formSubmissionHandler(req, res, next) {
     if (req.url.startsWith('/.netlify/') || req.method !== 'POST') return next()
 
@@ -334,8 +352,13 @@ const createFormSubmissionHandler = function ({ siteUrl, warn }) {
     })
     fakeRequest.headers = req.headers
 
+    const handlerName = getFormHandler({ getFunctionByName, warn })
+    if (!handlerName) {
+      return next()
+    }
+
     const originalUrl = new URL(req.url, 'http://localhost')
-    req.url = `/.netlify/functions/submission-created${originalUrl.search}`
+    req.url = `/.netlify/functions/${handlerName}${originalUrl.search}`
 
     const ct = parseContentType(req)
     let fields = {}
@@ -450,7 +473,7 @@ const getFunctionsServer = async function ({ getFunctionByName, siteUrl, warn, t
     }),
   )
   app.use(bodyParser.raw({ limit: '6mb', type: '*/*' }))
-  app.use(createFormSubmissionHandler({ siteUrl, warn }))
+  app.use(createFormSubmissionHandler({ getFunctionByName, siteUrl, warn }))
   app.use(
     expressLogging(console, {
       blacklist: ['/favicon.ico'],

tests/command.dev.test.js

@@ -694,6 +694,39 @@ testMatrix.forEach(({ args }) => {
     })
   })
 
+  test(testName('should handle form submission with a background function', args), async (t) => {
+    await withSiteBuilder('site-with-form-background-function', async (builder) => {
+      await builder
+        .withContentFile({
+          path: 'index.html',
+          content: '<h1>⊂◉‿◉つ</h1>',
+        })
+        .withNetlifyToml({
+          config: {
+            functions: { directory: 'functions' },
+          },
+        })
+        .withFunction({
+          path: 'submission-created-background.js',
+          handler: async (event) => ({
+            statusCode: 200,
+            body: JSON.stringify(event),
+          }),
+        })
+        .buildAsync()
+
+      await withDevServer({ cwd: builder.directory, args }, async (server) => {
+        const form = new FormData()
+        form.append('some', 'thing')
+        const response = await got.post(`${server.url}/?ding=dong`, {
+          body: form,
+        })
+        t.is(response.statusCode, 202)
+        t.is(response.body, '')
+      })
+    })
+  })
+
   test(testName('should not handle form submission when content type is `text/plain`', args), async (t) => {
     await withSiteBuilder('site-with-form-text-plain', async (builder) => {
       builder

tests/command.functions.test.js

@@ -247,4 +247,30 @@ test('should use settings from netlify.toml dev', async (t) => {
   })
 })
 
+test('should trigger background function from event', async (t) => {
+  await withSiteBuilder('site-with-ping-function', async (builder) => {
+    await builder
+      .withNetlifyToml({ config: { functions: { directory: 'functions' } } })
+      .withFunction({
+        path: 'identity-validate-background.js',
+        handler: async (event) => ({
+          statusCode: 200,
+          body: JSON.stringify(event.body),
+        }),
+      })
+      .buildAsync()
+
+    await withDevServer({ cwd: builder.directory }, async (server) => {
+      const stdout = await callCli(
+        ['functions:invoke', 'identity-validate-background', '--identity', `--port=${server.port}`],
+        {
+          cwd: builder.directory,
+        },
+      )
+      // background functions always return an empty response
+      t.is(stdout, '')
+    })
+  })
+})
+
 /* eslint-enable require-await */