feat(cli): use default template when GH is offline (#12194)

fix #12136 

I add a prompt if there is an error when trying to download example files.
Maybe could be better to add an error class and in create-app.ts on every "console.error" trow a new Exception and manage it in catch. What you think ? 👯

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

@@ -1,16 +1,16 @@
+import retry from 'async-retry'
 import chalk from 'chalk'
 import cpy from 'cpy'
 import fs from 'fs'
 import makeDir from 'make-dir'
 import os from 'os'
 import path from 'path'
-
 import {
-  hasExample,
-  hasRepo,
-  getRepoInfo,
   downloadAndExtractExample,
   downloadAndExtractRepo,
+  getRepoInfo,
+  hasExample,
+  hasRepo,
   RepoInfo,
 } from './helpers/examples'
 import { tryGitInit } from './helpers/git'
@@ -19,6 +19,8 @@ import { isFolderEmpty } from './helpers/is-folder-empty'
 import { getOnline } from './helpers/is-online'
 import { shouldUseYarn } from './helpers/should-use-yarn'
 
+export class DownloadError extends Error {}
+
 export async function createApp({
   appPath,
   useNpm,
@@ -75,7 +77,7 @@ export async function createApp({
         )
         process.exit(1)
       }
-    } else {
+    } else if (example !== '__internal-testing-retry') {
       const found = await hasExample(example)
 
       if (!found) {
@@ -109,24 +111,32 @@ export async function createApp({
   process.chdir(root)
 
   if (example) {
-    if (repoInfo) {
-      console.log(
-        `Downloading files from repo ${chalk.cyan(
-          example
-        )}. This might take a moment.`
-      )
-      console.log()
-      await downloadAndExtractRepo(root, repoInfo)
-    } else {
-      console.log(
-        `Downloading files for example ${chalk.cyan(
-          example
-        )}. This might take a moment.`
-      )
-      console.log()
-      await downloadAndExtractExample(root, example)
+    try {
+      if (repoInfo) {
+        const repoInfo2 = repoInfo
+        console.log(
+          `Downloading files from repo ${chalk.cyan(
+            example
+          )}. This might take a moment.`
+        )
+        console.log()
+        await retry(() => downloadAndExtractRepo(root, repoInfo2), {
+          retries: 3,
+        })
+      } else {
+        console.log(
+          `Downloading files for example ${chalk.cyan(
+            example
+          )}. This might take a moment.`
+        )
+        console.log()
+        await retry(() => downloadAndExtractExample(root, example), {
+          retries: 3,
+        })
+      }
+    } catch (reason) {
+      throw new DownloadError(reason)
     }
-
     // Copy our default `.gitignore` if the application did not provide one
     const ignorePath = path.join(root, '.gitignore')
     if (!fs.existsSync(ignorePath)) {

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

@@ -86,6 +86,10 @@ export async function downloadAndExtractExample(
   root: string,
   name: string
 ): Promise<void> {
+  if (name === '__internal-testing-retry') {
+    throw new Error('This is an internal example for testing the CLI.')
+  }
+
   try {
     return await pipeline(
       got.stream('https://codeload.github.com/zeit/next.js/tar.gz/canary'),

packages/create-next-app/index.ts

@@ -4,12 +4,11 @@ import Commander from 'commander'
 import path from 'path'
 import prompts from 'prompts'
 import checkForUpdate from 'update-check'
-
-import { createApp } from './create-app'
+import { createApp, DownloadError } from './create-app'
+import { listExamples } from './helpers/examples'
+import { shouldUseYarn } from './helpers/should-use-yarn'
 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 = ''
 
@@ -166,12 +165,32 @@ async function run(): Promise<void> {
   }
 
   const example = typeof program.example === 'string' && program.example.trim()
-  await createApp({
-    appPath: resolvedProjectPath,
-    useNpm: !!program.useNpm,
-    example: example && example !== 'default' ? example : undefined,
-    examplePath: program.examplePath,
-  })
+  try {
+    await createApp({
+      appPath: resolvedProjectPath,
+      useNpm: !!program.useNpm,
+      example: example && example !== 'default' ? example : undefined,
+      examplePath: program.examplePath,
+    })
+  } catch (reason) {
+    if (!(reason instanceof DownloadError)) {
+      throw reason
+    }
+
+    const res = await prompts({
+      type: 'confirm',
+      name: 'builtin',
+      message:
+        `Could not download "${example}" because of a connectivity issue between your machine and GitHub.\n` +
+        `Do you want to use the default template instead?`,
+      initial: true,
+    })
+    if (!res.builtin) {
+      throw reason
+    }
+
+    await createApp({ appPath: resolvedProjectPath, useNpm: !!program.useNpm })
+  }
 }
 
 const update = checkForUpdate(packageJson).catch(() => null)

packages/create-next-app/package.json

@@ -27,12 +27,14 @@
     "prepublish": "yarn release"
   },
   "devDependencies": {
+    "@types/async-retry": "1.4.2",
     "@types/node": "^12.6.8",
     "@types/prompts": "2.0.1",
     "@types/rimraf": "3.0.0",
     "@types/tar": "4.0.3",
     "@types/validate-npm-package-name": "3.0.0",
     "@zeit/ncc": "^0.20.4",
+    "async-retry": "1.3.1",
     "chalk": "2.4.2",
     "commander": "2.20.0",
     "cpy": "7.3.0",

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

@@ -1,12 +1,12 @@
 /* eslint-env jest */
-import path from 'path'
-import fs from 'fs-extra'
 import execa from 'execa'
+import fs from 'fs-extra'
 import os from 'os'
+import path from 'path'
 
 const cli = require.resolve('create-next-app/dist/index.js')
 
-jest.setTimeout(1000 * 60 * 2)
+jest.setTimeout(1000 * 60 * 5)
 
 const run = (cwd, ...args) => execa('node', [cli, ...args], { cwd })
 const runStarter = (cwd, ...args) => {
@@ -229,6 +229,36 @@ describe('create next app', () => {
         expect(res.stdout).toMatch(/Downloading files for example hello-world/)
       })
     })
+
+    it('should fall back to default template', async () => {
+      await usingTempDir(async (cwd) => {
+        const runExample = (...args) => {
+          const res = run(cwd, ...args)
+
+          function fallbackToTemplate(data) {
+            if (
+              /Do you want to use the default template instead/.test(
+                data.toString()
+              )
+            ) {
+              res.stdout.removeListener('data', fallbackToTemplate)
+              res.stdin.write('\n')
+            }
+          }
+
+          res.stdout.on('data', fallbackToTemplate)
+
+          return res
+        }
+
+        const res = await runExample(
+          'fail-example',
+          '--example',
+          '__internal-testing-retry'
+        )
+        expect(res.exitCode).toBe(0)
+      })
+    })
   }
 
   it('should allow an example named default', async () => {

yarn.lock

@@ -2407,6 +2407,13 @@
   version "1.3.1"
   resolved "https://registry.yarnpkg.com/@types/anymatch/-/anymatch-1.3.1.tgz#336badc1beecb9dacc38bea2cf32adf627a8421a"
 
+"@types/async-retry@1.4.2":
+  version "1.4.2"
+  resolved "https://registry.yarnpkg.com/@types/async-retry/-/async-retry-1.4.2.tgz#7f910188cd3893b51e32df51765ee8d5646053e3"
+  integrity sha512-GUDuJURF0YiJZ+CBjNQA0+vbP/VHlJbB0sFqkzsV7EcOPRfurVonXpXKAt3w8qIjM1TEzpz6hc6POocPvHOS3w==
+  dependencies:
+    "@types/retry" "*"
+
 "@types/babel__code-frame@7.0.1":
   version "7.0.1"
   resolved "https://registry.yarnpkg.com/@types/babel__code-frame/-/babel__code-frame-7.0.1.tgz#baf2529c4abbfb5e4008c845efcfe39a187e2f99"
@@ -2778,6 +2785,11 @@
   dependencies:
     "@types/node" "*"
 
+"@types/retry@*":
+  version "0.12.0"
+  resolved "https://registry.yarnpkg.com/@types/retry/-/retry-0.12.0.tgz#2b35eccfcee7d38cd72ad99232fbd58bffb3c84d"
+  integrity sha512-wWKOClTTiizcZhXnPY4wikVAwmdYHp8q6DmC+EJUzAMsycb7HB32Kh9RN4+0gExjmPmZSAQjgURXIGATPegAvA==
+
 "@types/rimraf@3.0.0":
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/@types/rimraf/-/rimraf-3.0.0.tgz#b9d03f090ece263671898d57bb7bb007023ac19f"
@@ -3585,6 +3597,13 @@ async-retry@1.2.3:
   dependencies:
     retry "0.12.0"
 
+async-retry@1.3.1:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/async-retry/-/async-retry-1.3.1.tgz#139f31f8ddce50c0870b0ba558a6079684aaed55"
+  integrity sha512-aiieFW/7h3hY0Bq5d+ktDBejxuwR78vRu9hDUdR8rNhSaQ29VzPL4AoIRG7D/c7tdenwOcKvgPM6tIxB3cB6HA==
+  dependencies:
+    retry "0.12.0"
+
 async-sema@3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/async-sema/-/async-sema-3.0.0.tgz#9e22d6783f0ab66a1cf330e21a905e39b3b3a975"