feat(@angular/cli): ask to install angular-eslint when running ng lint in new projects

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

@@ -6,8 +6,11 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+import { spawnSync } from 'child_process';
+import * as path from 'path';
 import { ArchitectCommand } from '../models/architect-command';
 import { Arguments } from '../models/interface';
+import { askConfirmation } from '../utilities/prompt';
 import { Schema as LintCommandSchema } from './lint';
 
 const MissingBuilder = `
@@ -22,11 +25,33 @@ For example:
 export class LintCommand extends ArchitectCommand<LintCommandSchema> {
   override readonly target = 'lint';
   override readonly multiTarget = true;
-  override readonly missingTargetError = MissingBuilder;
 
   override async initialize(options: LintCommandSchema & Arguments): Promise<number | void> {
     if (!options.help) {
       return super.initialize(options);
     }
   }
+
+  override async onMissingTarget(): Promise<void | number> {
+    this.logger.warn(MissingBuilder);
+
+    const shouldAdd = await askConfirmation('Would you like to add ESLint now?', true, false);
+    if (shouldAdd) {
+      // Run `ng add @angular-eslint/schematics`
+      const binPath = path.resolve(__dirname, '../bin/ng.js');
+      const { status, error } = spawnSync(
+        process.execPath,
+        [binPath, 'add', '@angular-eslint/schematics'],
+        {
+          stdio: 'inherit',
+        },
+      );
+
+      if (error) {
+        throw error;
+      }
+
+      return status ?? 0;
+    }
+  }
 }

packages/angular/cli/models/architect-command.ts

@@ -39,6 +39,23 @@ export abstract class ArchitectCommand<
   target: string | undefined;
   missingTargetError: string | undefined;
 
+  protected async onMissingTarget(projectName?: string): Promise<void | number> {
+    if (this.missingTargetError) {
+      this.logger.fatal(this.missingTargetError);
+
+      return 1;
+    }
+
+    if (projectName) {
+      this.logger.fatal(`Project '${projectName}' does not support the '${this.target}' target.`);
+    } else {
+      this.logger.fatal(`No projects support the '${this.target}' target.`);
+    }
+
+    return 1;
+  }
+
+  // eslint-disable-next-line max-lines-per-function
   public override async initialize(options: T & Arguments): Promise<number | void> {
     this._registry = new json.schema.CoreSchemaRegistry();
     this._registry.addPostTransform(json.schema.transforms.addUndefinedDefaults);
@@ -87,21 +104,12 @@ export abstract class ArchitectCommand<
       }
     }
 
-    if (targetProjectNames.length === 0) {
-      this.logger.fatal(
-        this.missingTargetError || `No projects support the '${this.target}' target.`,
-      );
-
-      return 1;
-    }
-
     if (projectName && !targetProjectNames.includes(projectName)) {
-      this.logger.fatal(
-        this.missingTargetError ||
-          `Project '${projectName}' does not support the '${this.target}' target.`,
-      );
+      return await this.onMissingTarget(projectName);
+    }
 
-      return 1;
+    if (targetProjectNames.length === 0) {
+      return await this.onMissingTarget();
     }
 
     if (!projectName && commandLeftovers && commandLeftovers.length > 0) {