feat: add --language flag to functions:create command (#3464)

* refactor: rename JS templates directory

* refactor: rename TS templates directory

* feat: add language flag

* refactor: rename variable

* chore: update docs

* chore: fix tests

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

docs/commands/functions.md

@@ -71,6 +71,7 @@ netlify functions:create
 
 - `name` (*string*) - function name
 - `url` (*string*) - pull template from URL
+- `language` (*string*) - function language
 - `debug` (*boolean*) - Print debugging information
 - `httpProxy` (*string*) - Proxy server address to route requests through.
 - `httpProxyCertificateFilename` (*string*) - Certificate file to use when connecting using a proxy server

src/commands/functions/create.js

@@ -31,8 +31,8 @@ const showGoTemplates = process.env.NETLIFY_EXPERIMENTAL_BUILD_GO_SOURCE === 'tr
 // each `value` property in this list, and that it matches the extension of the
 // files used by that language.
 const languages = [
-  { name: 'JavaScript', value: 'js' },
-  { name: 'TypeScript', value: 'ts' },
+  { name: 'JavaScript', value: 'javascript' },
+  { name: 'TypeScript', value: 'typescript' },
   showGoTemplates && { name: 'Go', value: 'go' },
 ]
 
@@ -69,6 +69,7 @@ FunctionsCreateCommand.aliases = ['function:create']
 FunctionsCreateCommand.flags = {
   name: flagsLib.string({ char: 'n', description: 'function name' }),
   url: flagsLib.string({ char: 'u', description: 'pull template from URL' }),
+  language: flagsLib.string({ char: 'l', description: 'function language' }),
   ...FunctionsCreateCommand.flags,
 }
 module.exports = FunctionsCreateCommand
@@ -155,7 +156,7 @@ const formatRegistryArrayForInquirer = function (lang) {
 }
 
 // pick template from our existing templates
-const pickTemplate = async function () {
+const pickTemplate = async function ({ language: languageFromFlag }) {
   const specialCommands = [
     new inquirer.Separator(),
     {
@@ -170,16 +171,30 @@ const pickTemplate = async function () {
     },
     new inquirer.Separator(),
   ]
-  const { language } = await inquirer.prompt({
-    choices: languages.filter(Boolean),
-    message: 'Select the language of your function',
-    name: 'language',
-    type: 'list',
-  })
+
+  let language = languageFromFlag
+
+  if (language === undefined) {
+    const { language: languageFromPrompt } = await inquirer.prompt({
+      choices: languages.filter(Boolean),
+      message: 'Select the language of your function',
+      name: 'language',
+      type: 'list',
+    })
+
+    language = languageFromPrompt
+  }
 
   inquirer.registerPrompt('autocomplete', inquirerAutocompletePrompt)
 
-  const templatesForLanguage = formatRegistryArrayForInquirer(language)
+  let templatesForLanguage
+
+  try {
+    templatesForLanguage = formatRegistryArrayForInquirer(language)
+  } catch (_) {
+    throw error(`Invalid language: ${language}`)
+  }
+
   const { chosenTemplate } = await inquirer.prompt({
     name: 'chosenTemplate',
     message: 'Pick a template',
@@ -373,7 +388,7 @@ const installDeps = async ({ functionPackageJson, functionPath, functionsDir })
 // no --url flag specified, pick from a provided template
 const scaffoldFromTemplate = async function (context, flags, args, functionsDir) {
   // pull the rest of the metadata from the template
-  const chosenTemplate = await pickTemplate()
+  const chosenTemplate = await pickTemplate(flags)
   if (chosenTemplate === 'url') {
     const { chosenUrl } = await inquirer.prompt([
       {

tests/command.functions.test.js

@@ -70,7 +70,7 @@ test('should create a new function directory when none is found', async (t) => {
       },
       {
         question: 'Select the language of your function',
-        answer: answerWithValue('ts'),
+        answer: answerWithValue(CONFIRM),
       },
       {
         question: 'Pick a template',
@@ -142,7 +142,7 @@ test('should install function template dependencies on a site-level `package.jso
       },
       {
         question: 'Select the language of your function',
-        answer: answerWithValue('ts'),
+        answer: answerWithValue(CONFIRM),
       },
       {
         question: 'Pick a template',
@@ -218,7 +218,7 @@ test('should install function template dependencies in the function sub-director
       },
       {
         question: 'Select the language of your function',
-        answer: answerWithValue('ts'),
+        answer: answerWithValue(CONFIRM),
       },
       {
         question: 'Pick a template',
@@ -286,7 +286,7 @@ test('should not create a new function directory when one is found', async (t) =
     const createFunctionQuestions = [
       {
         question: 'Select the language of your function',
-        answer: answerWithValue('ts'),
+        answer: answerWithValue(CONFIRM),
       },
       {
         question: 'Pick a template',
@@ -317,6 +317,132 @@ test('should not create a new function directory when one is found', async (t) =
   })
 })
 
+test('should only show function templates for the language specified via the --language flag, if one is present', async (t) => {
+  const siteInfo = {
+    admin_url: 'https://app.netlify.com/sites/site-name/overview',
+    ssl_url: 'https://site-name.netlify.app/',
+    id: 'site_id',
+    name: 'site-name',
+    build_settings: { repo_url: 'https://github.com/owner/repo' },
+  }
+
+  const routes = [
+    {
+      path: 'accounts',
+      response: [{ slug: 'test-account' }],
+    },
+    { path: 'sites/site_id/service-instances', response: [] },
+    { path: 'sites/site_id', response: siteInfo },
+    {
+      path: 'sites',
+      response: [siteInfo],
+    },
+    { path: 'sites/site_id', method: 'patch', response: {} },
+  ]
+
+  await withSiteBuilder('site-with-no-functions-dir', async (builder) => {
+    await builder.buildAsync()
+
+    const createFunctionQuestions = [
+      {
+        question: 'Enter the path, relative to your site',
+        answer: answerWithValue('test/functions'),
+      },
+      {
+        question: 'Pick a template',
+        answer: answerWithValue(CONFIRM),
+      },
+      {
+        question: 'Name your function',
+        answer: answerWithValue(CONFIRM),
+      },
+    ]
+
+    await withMockApi(routes, async ({ apiUrl }) => {
+      const childProcess = execa(cliPath, ['functions:create', '--language', 'javascript'], {
+        env: {
+          NETLIFY_API_URL: apiUrl,
+          NETLIFY_SITE_ID: 'site_id',
+          NETLIFY_AUTH_TOKEN: 'fake-token',
+        },
+        cwd: builder.directory,
+      })
+
+      handleQuestions(childProcess, createFunctionQuestions)
+
+      await childProcess
+
+      t.is(await fs.fileExistsAsync(`${builder.directory}/test/functions/hello-world/hello-world.js`), true)
+    })
+  })
+})
+
+test('throws an error when the --language flag contains an unsupported value', async (t) => {
+  const siteInfo = {
+    admin_url: 'https://app.netlify.com/sites/site-name/overview',
+    ssl_url: 'https://site-name.netlify.app/',
+    id: 'site_id',
+    name: 'site-name',
+    build_settings: { repo_url: 'https://github.com/owner/repo' },
+  }
+
+  const routes = [
+    {
+      path: 'accounts',
+      response: [{ slug: 'test-account' }],
+    },
+    { path: 'sites/site_id/service-instances', response: [] },
+    { path: 'sites/site_id', response: siteInfo },
+    {
+      path: 'sites',
+      response: [siteInfo],
+    },
+    { path: 'sites/site_id', method: 'patch', response: {} },
+  ]
+
+  await withSiteBuilder('site-with-no-functions-dir', async (builder) => {
+    await builder.buildAsync()
+
+    const createFunctionQuestions = [
+      {
+        question: 'Enter the path, relative to your site',
+        answer: answerWithValue('test/functions'),
+      },
+      {
+        question: 'Pick a template',
+        answer: answerWithValue(CONFIRM),
+      },
+      {
+        question: 'Name your function',
+        answer: answerWithValue(CONFIRM),
+      },
+    ]
+
+    await withMockApi(routes, async ({ apiUrl }) => {
+      const childProcess = execa(cliPath, ['functions:create', '--language', 'coffeescript'], {
+        env: {
+          NETLIFY_API_URL: apiUrl,
+          NETLIFY_SITE_ID: 'site_id',
+          NETLIFY_AUTH_TOKEN: 'fake-token',
+        },
+        cwd: builder.directory,
+      })
+
+      handleQuestions(childProcess, createFunctionQuestions)
+
+      try {
+        await childProcess
+
+        t.fail()
+      } catch (error) {
+        t.true(error.message.includes('Invalid language: coffeescript'))
+      }
+
+      t.is(await fs.fileExistsAsync(`${builder.directory}/test/functions/hello-world/hello-world.js`), false)
+    })
+  })
+})
+
 const DEFAULT_PORT = 9999
 const SERVE_TIMEOUT = 180000