feat(@angular-devkit/schematics): support calling a task by file path when using a FileSystemEngineHost

Author: clydin

etc/api/angular_devkit/schematics/tools/index.d.ts

@@ -43,6 +43,8 @@ export declare class FileSystemEngineHost extends FileSystemEngineHostBase {
     } | null;
     protected _transformCollectionDescription(name: string, desc: Partial<FileSystemCollectionDesc>): FileSystemCollectionDesc;
     protected _transformSchematicDescription(name: string, _collection: FileSystemCollectionDesc, desc: Partial<FileSystemSchematicDesc>): FileSystemSchematicDesc;
+    createTaskExecutor(name: string): Observable<TaskExecutor>;
+    hasTaskExecutor(name: string): boolean;
 }
 
 export declare abstract class FileSystemEngineHostBase implements EngineHost<FileSystemCollectionDescription, FileSystemSchematicDescription> {

packages/angular_devkit/schematics/tools/file-system-engine-host.ts

@@ -7,7 +7,9 @@
  */
 import { existsSync } from 'fs';
 import { join } from 'path';
-import { RuleFactory } from '../src';
+import { Observable, from, throwError } from 'rxjs';
+import { catchError } from 'rxjs/operators';
+import { RuleFactory, TaskExecutor, UnregisteredTaskException } from '../src';
 import { FileSystemCollectionDesc, FileSystemSchematicDesc } from './description';
 import { ExportStringRef } from './export-ref';
 import {
@@ -81,4 +83,33 @@ export class FileSystemEngineHost extends FileSystemEngineHostBase {
 
     return desc as FileSystemSchematicDesc;
   }
+
+  hasTaskExecutor(name: string): boolean {
+    if (super.hasTaskExecutor(name)) {
+      return true;
+    }
+
+    try {
+      const maybePath = require.resolve(join(this._root, name));
+      if (existsSync(maybePath)) {
+        return true;
+      }
+    } catch {}
+
+    return false;
+  }
+
+  createTaskExecutor(name: string): Observable<TaskExecutor> {
+    if (!super.hasTaskExecutor(name)) {
+      try {
+        const path = require.resolve(join(this._root, name));
+
+        return from(import(path).then(mod => mod.default())).pipe(
+          catchError(() => throwError(new UnregisteredTaskException(name))),
+        );
+      } catch {}
+    }
+
+    return super.createTaskExecutor(name);
+  }
 }

packages/angular_devkit/schematics/tools/file-system-engine-host_spec.ts

@@ -10,7 +10,7 @@ import { normalize, virtualFs } from '@angular-devkit/core';
 import { HostSink, HostTree, SchematicEngine } from '@angular-devkit/schematics';
 import { FileSystemEngineHost } from '@angular-devkit/schematics/tools';
 import * as path from 'path';
-import { of as observableOf } from 'rxjs';
+import { from, of as observableOf } from 'rxjs';
 
 
 describe('FileSystemEngineHost', () => {
@@ -300,4 +300,40 @@ describe('FileSystemEngineHost', () => {
       })
       .then(done, done.fail);
   });
+
+  it('discovers a file-based task', () => {
+    const engineHost = new FileSystemEngineHost(root);
+
+    expect(engineHost.hasTaskExecutor('file-tasks/file-task.js')).toBeTruthy();
+  });
+
+  it('creates a file-based task', done => {
+    const engineHost = new FileSystemEngineHost(root);
+
+    engineHost.createTaskExecutor('file-tasks/file-task.js').subscribe(executor => {
+      expect(executor).toBeTruthy();
+      from(executor(undefined, undefined as any)).toPromise().then(() => done.fail, () => done());
+    }, done.fail);
+  });
+
+  it('allows executing a schematic with a file-based task', done => {
+    const engineHost = new FileSystemEngineHost(root);
+    const engine = new SchematicEngine(engineHost);
+    const host = new virtualFs.test.TestHost();
+
+    const collection = engine.createCollection('file-tasks');
+    const schematic = collection.createSchematic('schematic-1');
+
+    schematic.call({}, observableOf(new HostTree(host))).toPromise()
+      .then(tree => new HostSink(host).commit(tree).toPromise())
+      .then(() => engine.executePostTasks().toPromise())
+      .then(() => done.fail())
+      .catch(reason => {
+        if (reason.message === 'task exception') {
+          done();
+        } else {
+          done.fail();
+        }
+      });
+  });
 });

tests/angular_devkit/schematics/tools/file-system-engine-host/BUILD

@@ -16,7 +16,7 @@ ts_library(
         ],
     ),
     data = glob(
-        include = ["**/collection.json"],
+        include = ["**/collection.json", "**/*.js"],
     ),
     deps = [
         "//packages/angular_devkit/schematics",

tests/angular_devkit/schematics/tools/file-system-engine-host/file-tasks/collection.json

@@ -0,0 +1,9 @@
+{
+    "name": "file-tasks",
+    "schematics": {
+      "schematic-1": {
+        "description": "1",
+        "factory": "./factory"
+      }
+    }
+  }

tests/angular_devkit/schematics/tools/file-system-engine-host/file-tasks/factory.ts

@@ -0,0 +1,19 @@
+/**
+ * @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
+ */
+// tslint:disable-next-line:no-implicit-dependencies
+import { SchematicContext, Tree } from '@angular-devkit/schematics';
+
+export default function() {
+  return (_: Tree, context: SchematicContext) => {
+    context.addTask({
+      toConfiguration() {
+        return { name: 'file-tasks/file-task.js' };
+      },
+    });
+  };
+}

tests/angular_devkit/schematics/tools/file-system-engine-host/file-tasks/file-task.js

@@ -0,0 +1,7 @@
+function default_1() {
+    return async () => {
+        throw new Error('task exception');
+    }
+}
+
+exports.default = default_1;