feat(@angular/cli): confirm ng add action before installation

BREAKING CHANGE:
The `ng add` command will now ask the user to confirm the package and version prior to installing and executing an uninstalled package.
This new behavior allows a user to abort the action if the version selected is not appropriate or if a typo occurred on the command line and an incorrect package would be installed.
A `--skip-confirmation` option has been added to skip the prompt and directly install and execute the package. This option is useful in CI and non-TTY scenarios such as automated scripts.

Author: clydin

packages/angular/cli/commands/add-impl.ts

@@ -22,7 +22,9 @@ import {
   fetchPackageManifest,
   fetchPackageMetadata,
 } from '../utilities/package-metadata';
+import { askConfirmation } from '../utilities/prompt';
 import { Spinner } from '../utilities/spinner';
+import { isTTY } from '../utilities/tty';
 import { Schema as AddCommandSchema } from './add';
 
 const npa = require('npm-package-arg');
@@ -179,6 +181,28 @@ export class AddCommand extends SchematicCommand<AddCommandSchema> {
       return 1;
     }
 
+    if (!options.skipConfirmation) {
+      const confirmationResponse = await askConfirmation(
+        `\nThe package ${colors.blue(packageIdentifier.raw)} will be installed and executed.\n` +
+          'Would you like to proceed?',
+        true,
+        false,
+      );
+
+      if (!confirmationResponse) {
+        if (!isTTY) {
+          this.logger.error(
+            'No terminal detected. ' +
+              `'--skip-confirmation' can be used to bypass installation confirmation. ` +
+              `Ensure package name is correct prior to '--skip-confirmation' option usage.`,
+          );
+        }
+        this.logger.error('Command aborted.');
+
+        return 1;
+      }
+    }
+
     try {
       spinner.start('Installing package...');
       if (savePackage === false) {

packages/angular/cli/commands/add.json

@@ -35,6 +35,11 @@
           "description": "Display additional details about internal operations during execution.",
           "type": "boolean",
           "default": false
+        },
+        "skipConfirmation": {
+          "description": "Skip asking a confirmation prompt before installing and executing the package. Ensure package name is correct prior to using this option.",
+          "type": "boolean",
+          "default": false
         }
       },
       "required": [

packages/angular/cli/utilities/prompt.ts

@@ -0,0 +1,31 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import * as inquirer from 'inquirer';
+import { isTTY } from './tty';
+
+export async function askConfirmation(
+  message: string,
+  defaultResponse: boolean,
+  noTTYResponse?: boolean,
+): Promise<boolean> {
+  if (!isTTY()) {
+    return noTTYResponse ?? defaultResponse;
+  }
+
+  const question: inquirer.Question = {
+    type: 'confirm',
+    name: 'confirmation',
+    prefix: '',
+    message,
+    default: defaultResponse,
+  };
+
+  const answers = await inquirer.prompt([question]);
+
+  return answers['confirmation'];
+}

tests/legacy-cli/e2e/tests/build/material.ts

@@ -8,7 +8,7 @@ const snapshots = require('../../ng-snapshot/package.json');
 
 export default async function () {
   const tag = await isPrereleaseCli() ?  '@next' : '';
-  await ng('add', `@angular/material${tag}`);
+  await ng('add', `@angular/material${tag}`, '--skip-confirmation');
 
   const isSnapshotBuild = getGlobalVariable('argv')['ng-snapshots'];
   if (isSnapshotBuild) {

tests/legacy-cli/e2e/tests/commands/add/add-material.ts

@@ -11,14 +11,14 @@ export default async function () {
   const tag = await isPrereleaseCli() ?  '@next' : '';
 
   try {
-    await ng('add', `@angular/material${tag}`, '--unknown');
+    await ng('add', `@angular/material${tag}`, '--unknown', '--skip-confirmation');
   } catch (error) {
     if (!(error.message && error.message.includes(`Unknown option: '--unknown'`))) {
       throw error;
     }
   }
 
-  await ng('add',  `@angular/material${tag}`, '--theme', 'custom', '--verbose');
+  await ng('add',  `@angular/material${tag}`, '--theme', 'custom', '--verbose', '--skip-confirmation');
   await expectFileToMatch('package.json', /@angular\/material/);
 
   // Clean up existing cdk package

tests/legacy-cli/e2e/tests/commands/add/add-pwa-yarn.ts

@@ -13,7 +13,7 @@ export default async function () {
 
     // set yarn as package manager
     await ng('config', 'cli.packageManager', 'yarn');
-    await ng('add', '@angular/pwa');
+    await ng('add', '@angular/pwa', '--skip-confirmation');
     await expectFileToExist(join(process.cwd(), 'src/manifest.webmanifest'));
 
     // Angular PWA doesn't install as a dependency

tests/legacy-cli/e2e/tests/commands/add/add-pwa.ts

@@ -5,7 +5,7 @@ import { ng } from '../../../utils/process';
 export default async function () {
   // forcibly remove in case another test doesn't clean itself up
   await rimraf('node_modules/@angular/pwa');
-  await ng('add', '@angular/pwa');
+  await ng('add', '@angular/pwa', '--skip-confirmation');
   await expectFileToExist(join(process.cwd(), 'src/manifest.webmanifest'));
 
   // Angular PWA doesn't install as a dependency

tests/legacy-cli/e2e/tests/commands/add/add-version.ts

@@ -3,7 +3,7 @@ import { ng } from '../../../utils/process';
 
 
 export default async function () {
-  await ng('add', '@angular-devkit-tests/ng-add-simple@^1.0.0');
+  await ng('add', '@angular-devkit-tests/ng-add-simple@^1.0.0', '--skip-confirmation');
   await expectFileToMatch('package.json', /\/ng-add-simple.*\^1\.0\.0/);
   await expectFileToExist('ng-add-test');
   await rimraf('node_modules/@angular-devkit-tests/ng-add-simple');

tests/legacy-cli/e2e/tests/commands/add/add.ts

@@ -3,7 +3,7 @@ import { ng } from '../../../utils/process';
 
 
 export default async function () {
-  await ng('add', '@angular-devkit-tests/ng-add-simple');
+  await ng('add', '@angular-devkit-tests/ng-add-simple', '--skip-confirmation');
   await expectFileToMatch('package.json', /@angular-devkit-tests\/ng-add-simple/);
   await expectFileToExist('ng-add-test');
   await rimraf('node_modules/@angular-devkit-tests/ng-add-simple');

tests/legacy-cli/e2e/tests/commands/add/dir.ts

@@ -4,6 +4,6 @@ import { ng } from '../../../utils/process';
 
 
 export default async function () {
-  await ng('add', assetDir('add-collection'), '--name=blah');
+  await ng('add', assetDir('add-collection'), '--name=blah', '--skip-confirmation');
   await expectFileToExist('blah');
 }

tests/legacy-cli/e2e/tests/commands/add/file.ts

@@ -4,6 +4,6 @@ import { ng } from '../../../utils/process';
 
 
 export default async function () {
-  await ng('add', assetDir('add-collection.tgz'), '--name=blah');
+  await ng('add', assetDir('add-collection.tgz'), '--name=blah', '--skip-confirmation');
   await expectFileToExist('blah');
 }

tests/legacy-cli/e2e/tests/commands/add/peer.ts

@@ -4,17 +4,17 @@ import { ng } from '../../../utils/process';
 const warning = 'Adding the package may not succeed.';
 
 export default async function () {
-  const { stderr: bad } = await ng('add', assetDir('add-collection-peer-bad'));
+  const { stderr: bad } = await ng('add', assetDir('add-collection-peer-bad'), '--skip-confirmation');
   if (!bad.includes(warning)) {
     throw new Error('peer warning not shown on bad package');
   }
 
-  const { stderr: base  } = await ng('add', assetDir('add-collection'));
+  const { stderr: base  } = await ng('add', assetDir('add-collection'), '--skip-confirmation');
   if (base.includes(warning)) {
     throw new Error('peer warning shown on base package');
   }
 
-  const { stderr: good  } = await ng('add', assetDir('add-collection-peer-good'));
+  const { stderr: good  } = await ng('add', assetDir('add-collection-peer-good'), '--skip-confirmation');
   if (good.includes(warning)) {
     throw new Error('peer warning shown on good package');
   }

tests/legacy-cli/e2e/tests/commands/add/registry-option.ts

@@ -15,9 +15,9 @@ export default async function () {
   process.env['NPM_CONFIG_REGISTRY'] = undefined;
 
   try {
-    await expectToFail(() => ng('add', '@angular/pwa'));
+    await expectToFail(() => ng('add', '@angular/pwa', '--skip-confirmation'));
 
-    await ng('add', `--registry=${testRegistry}`, '@angular/pwa');
+    await ng('add', `--registry=${testRegistry}`, '@angular/pwa', '--skip-confirmation');
     await expectFileToExist('src/manifest.webmanifest');
   } finally {
     process.env['NPM_CONFIG_REGISTRY'] = originalRegistryVariable;

tests/legacy-cli/e2e/tests/commands/add/version-specifier.ts

@@ -10,25 +10,25 @@ export default async function () {
 
   const tag = await isPrereleaseCli() ?  '@next' : '';
 
-  await ng('add',  `@angular/localize${tag}`);
+  await ng('add',  `@angular/localize${tag}`, '--skip-confirmation');
   await expectFileToMatch('package.json', /@angular\/localize/);
 
-  const output1 = await ng('add', '@angular/localize');
+  const output1 = await ng('add', '@angular/localize', '--skip-confirmation');
   if (!output1.stdout.includes('Skipping installation: Package already installed')) {
     throw new Error('Installation was not skipped');
   }
 
-  const output2 = await ng('add', '@angular/localize@latest');
+  const output2 = await ng('add', '@angular/localize@latest', '--skip-confirmation');
   if (output2.stdout.includes('Skipping installation: Package already installed')) {
     throw new Error('Installation should not have been skipped');
   }
 
-  const output3 = await ng('add', '@angular/[email protected]');
+  const output3 = await ng('add', '@angular/[email protected]', '--skip-confirmation');
   if (output3.stdout.includes('Skipping installation: Package already installed')) {
     throw new Error('Installation should not have been skipped');
   }
 
-  const output4 = await ng('add', '@angular/localize@10');
+  const output4 = await ng('add', '@angular/localize@10', '--skip-confirmation');
   if (!output4.stdout.includes('Skipping installation: Package already installed')) {
     throw new Error('Installation was not skipped');
   }

tests/legacy-cli/e2e/tests/misc/invalid-schematic-dependencies.ts

@@ -29,7 +29,7 @@ export default async function () {
   await installPackage('@schematics/angular@7');
 
   const tag = (await isPrereleaseCli()) ? '@next' : '';
-  await ng('add', `@angular/material${tag}`);
+  await ng('add', `@angular/material${tag}`, '--skip-confirmation');
   await expectFileToMatch('package.json', /@angular\/material/);
 
   // Clean up existing cdk package