Confirm if user wants example when creating app (#10543)

* Confirm if user wants example when creating app

* Only ask user to choose example if they provide --example flag

* Simplify the search

* Added test

* Use a select to pick the template

* Updated test

* check for lowercase and updated no example message

* Add message if no template is selected

* Updated tests

* Handle error if fetching the examples fails

* Fixed tests

* Updated test timeout

* Update examples.ts

Co-authored-by: merelinguist <merelinguist@users.noreply.github.com>
Co-authored-by: Luis Alvarez <luis@zeit.co>
Co-authored-by: Tim Neutkens <tim@timneutkens.nl>
Co-authored-by: Joe Haddad <joe.haddad@zeit.co>

packages/create-next-app/helpers/examples.ts

@@ -86,3 +86,10 @@ export function downloadAndExtractExample(
     tar.extract({ cwd: root, strip: 3 }, [`next.js-canary/examples/${name}`])
   )
 }
+
+export async function listExamples(): Promise<any> {
+  const res = await got(
+    'https://api.github.com/repositories/70107786/contents/examples'
+  )
+  return JSON.parse(res.body)
+}

packages/create-next-app/index.ts

@@ -9,6 +9,7 @@ import { createApp } from './create-app'
 import { validateNpmName } from './helpers/validate-pkg'
 import packageJson from './package.json'
 import { shouldUseYarn } from './helpers/should-use-yarn'
+import { listExamples } from './helpers/examples'
 
 let projectPath: string = ''
 
@@ -21,7 +22,7 @@ const program = new Commander.Command(packageJson.name)
   })
   .option('--use-npm')
   .option(
-    '-e, --example <name>|<github-url>',
+    '-e, --example [name]|[github-url]',
     `
 
   An example to bootstrap the app with. You can use an example name
@@ -98,6 +99,72 @@ async function run() {
     process.exit(1)
   }
 
+  if (!program.example) {
+    const template = await prompts({
+      type: 'select',
+      name: 'value',
+      message: 'Pick a template',
+      choices: [
+        { title: 'Default starter app', value: 'default' },
+        { title: 'Example from the Next.js repo', value: 'example' },
+      ],
+    })
+
+    if (!template.value) {
+      console.log()
+      console.log('Please specify the template')
+      process.exit(1)
+    }
+
+    if (template.value === 'example') {
+      let examplesJSON: any
+
+      try {
+        examplesJSON = await listExamples()
+      } catch (error) {
+        console.log()
+        console.log(
+          'Failed to fetch the list of examples with the following error:'
+        )
+        console.error(error)
+        console.log()
+        console.log('Switching to the default starter app')
+        console.log()
+      }
+
+      if (examplesJSON) {
+        const choices = examplesJSON.map((example: any) => ({
+          title: example.name,
+          value: example.name,
+        }))
+        // The search function built into `prompts` isn’t very helpful:
+        // someone searching for `styled-components` would get no results since
+        // the example is called `with-styled-components`, and `prompts` searches
+        // the beginnings of titles.
+        const nameRes = await prompts({
+          type: 'autocomplete',
+          name: 'exampleName',
+          message: 'Pick an example',
+          choices,
+          suggest: (input: any, choices: any) => {
+            const regex = new RegExp(input, 'i')
+            return choices.filter((choice: any) => regex.test(choice.title))
+          },
+        })
+
+        if (!nameRes.exampleName) {
+          console.log()
+          console.log(
+            'Please specify an example or use the default starter app.'
+          )
+          process.exit(1)
+        }
+
+        program.example = nameRes.exampleName
+      }
+    }
+  }
+
   await createApp({
     appPath: resolvedProjectPath,
     useNpm: !!program.useNpm,
@@ -130,6 +197,7 @@ async function notifyUpdate() {
       )
       console.log()
     }
+    process.exit()
   } catch {
     // ignore error
   }

test/integration/create-next-app/index.test.js

@@ -13,31 +13,43 @@ const cwd = path.join(
 )
 
 const run = (...args) => execa('node', [cli, ...args], { cwd })
+const runStarter = (...args) => {
+  const res = run(...args)
+
+  res.stdout.on('data', data => {
+    const stdout = data.toString()
+
+    if (/Pick a template/.test(stdout)) {
+      res.stdin.write('\n')
+    }
+  })
+
+  return res
+}
 
 describe('create next app', () => {
   beforeAll(async () => {
-    jest.setTimeout(1000 * 60)
+    jest.setTimeout(1000 * 60 * 2)
     await fs.mkdirp(cwd)
   })
 
   it('non-empty directory', async () => {
     const projectName = 'non-empty-directory'
-
     await fs.mkdirp(path.join(cwd, projectName))
     const pkg = path.join(cwd, projectName, 'package.json')
     fs.writeFileSync(pkg, '{ "foo": "bar" }')
 
     expect.assertions(1)
     try {
-      await run(projectName)
+      await runStarter(projectName)
     } catch (e) {
       expect(e.stdout).toMatch(/contains files that could conflict/)
     }
   })
 
   it('empty directory', async () => {
     const projectName = 'empty-directory'
-    const res = await run(projectName)
+    const res = await runStarter(projectName)
 
     expect(res.exitCode).toBe(0)
     expect(
@@ -150,4 +162,42 @@ describe('create next app', () => {
       fs.existsSync(path.join(cwd, projectName, '.gitignore'))
     ).toBeTruthy()
   })
+
+  it('should allow to manually select an example', async () => {
+    const runExample = (...args) => {
+      const res = run(...args)
+
+      function pickExample(data) {
+        if (/hello-world/.test(data.toString())) {
+          res.stdout.removeListener('data', pickExample)
+          res.stdin.write('\n')
+        }
+      }
+
+      function searchExample(data) {
+        if (/Pick an example/.test(data.toString())) {
+          res.stdout.removeListener('data', searchExample)
+          res.stdin.write('hello-world')
+          res.stdout.on('data', pickExample)
+        }
+      }
+
+      function selectExample(data) {
+        if (/Pick a template/.test(data.toString())) {
+          res.stdout.removeListener('data', selectExample)
+          res.stdin.write('\u001b[B\n') // Down key and enter
+          res.stdout.on('data', searchExample)
+        }
+      }
+
+      res.stdout.on('data', selectExample)
+
+      return res
+    }
+
+    const res = await runExample('no-example')
+
+    expect(res.exitCode).toBe(0)
+    expect(res.stdout).toMatch(/Downloading files for example hello-world/)
+  })
 })