feat(@schematics/angular): add lazy module path fixer

package.json

@@ -62,6 +62,7 @@
     ]
   },
   "dependencies": {
+    "@phenomnomnominal/tsquery": "3.0.0",
     "@types/debug": "^4.1.2",
     "@types/node-fetch": "^2.1.6",
     "@types/progress": "^2.0.3",

packages/schematics/angular/BUILD

@@ -50,8 +50,10 @@ ts_library(
         "//packages/angular_devkit/schematics",
         "//packages/angular_devkit/schematics:tasks",
         "//packages/schematics/angular/third_party/github.com/Microsoft/TypeScript",
+        "@npm//@phenomnomnominal/tsquery",
         "@npm//@types/node",
         "@npm//rxjs",
+        "@npm//tslint",
     ],
 )
 
@@ -83,12 +85,15 @@ ts_library(
     deps = ALL_SCHEMA_DEPS + [
         ":angular",
         "//packages/angular_devkit/core",
+        "//packages/angular_devkit/core:node_testing",
         "//packages/angular_devkit/schematics",
         "//packages/angular_devkit/schematics:testing",
         "//packages/schematics/angular/third_party/github.com/Microsoft/TypeScript",
+        "@npm//@phenomnomnominal/tsquery",
         "@npm//@types/node",
         "@npm//@types/jasmine",
         "@npm//rxjs",
+        "@npm//tslint",
     ],
     testonly = True,
     # @external_begin

packages/schematics/angular/migrations/migration-collection.json

@@ -34,6 +34,11 @@
       "version": "8.0.0-beta.12",
       "factory": "./update-8",
       "description": "Update an Angular CLI project to version 8."
+    },
+    "migration-08": {
+      "version": "8.0.0-beta.14",
+      "factory": "./update-8/#updateLazyModulePaths",
+      "description": "Update an Angular CLI project to version 8."
     }
   }
 }

packages/schematics/angular/migrations/update-8/index.ts

@@ -14,6 +14,8 @@ import { updatePackageJson, updateTsLintConfig } from './codelyzer-5';
 import { updateES5Projects } from './differential-loading';
 import { dropES2015Polyfills } from './drop-es6-polyfills';
 
+export { updateLazyModulePaths } from './update-lazy-module-paths';
+
 export default function(): Rule {
   return () => {
     return chain([

packages/schematics/angular/migrations/update-8/rules/noLazyModulePathsRule.ts

@@ -0,0 +1,54 @@
+/**
+ * @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 { tsquery } from '@phenomnomnominal/tsquery';
+import {
+    Replacement,
+    RuleFailure,
+    Rules,
+} from 'tslint'; // tslint:disable-line:no-implicit-dependencies
+import * as ts from '../../../third_party/github.com/Microsoft/TypeScript/lib/typescript';
+
+ // Constants:
+const LOAD_CHILDREN_SPLIT = '#';
+const NOT_CHILDREN_QUERY = `:not(:has(Identifier[name="children"]))`;
+const HAS_LOAD_CHILDREN_QUERY = `:has(Identifier[name="loadChildren"])`;
+const LAZY_VALUE_QUERY = `StringLiteral[value=/.*${LOAD_CHILDREN_SPLIT}.*/]`;
+const LOAD_CHILDREN_ASSIGNMENT_QUERY =
+  `PropertyAssignment${NOT_CHILDREN_QUERY}${HAS_LOAD_CHILDREN_QUERY}:has(${LAZY_VALUE_QUERY})`;
+
+const FAILURE_MESSAGE = 'Found magic `loadChildren` string. Use a function with `import` instead.';
+
+export class Rule extends Rules.AbstractRule {
+  public apply (ast: ts.SourceFile): Array<RuleFailure> {
+    return tsquery(ast, LOAD_CHILDREN_ASSIGNMENT_QUERY).map(result => {
+      const [valueNode] = tsquery(result, LAZY_VALUE_QUERY);
+      let fix = this._promiseReplacement(valueNode.text);
+
+      // Try to fix indentation in replacement:
+      const { character } = ast.getLineAndCharacterOfPosition(result.getStart());
+      fix = fix.replace(/\n/g, `\n${' '.repeat(character)}`);
+
+      const replacement = new Replacement(valueNode.getStart(), valueNode.getWidth(), fix);
+      const start = result.getStart();
+      const end = result.getEnd();
+
+      return new RuleFailure(ast, start, end, FAILURE_MESSAGE, this.ruleName, replacement);
+    });
+  }
+
+  private _promiseReplacement (loadChildren: string): string {
+    const [path, moduleName] = this._getChunks(loadChildren);
+
+    return `() => import('${path}').then(m => m.${moduleName})`;
+  }
+
+  private _getChunks (loadChildren: string): Array<string> {
+    return loadChildren.split(LOAD_CHILDREN_SPLIT);
+  }
+}

packages/schematics/angular/migrations/update-8/update-lazy-module-paths.ts

@@ -0,0 +1,30 @@
+/**
+ * @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 {
+  Rule,
+  SchematicContext,
+  Tree,
+} from '@angular-devkit/schematics';
+import {
+  TslintFixTask,
+} from '@angular-devkit/schematics/tasks';
+import * as path from 'path';
+
+export const updateLazyModulePaths = (): Rule => {
+  return (_: Tree, context: SchematicContext) => {
+    context.addTask(new TslintFixTask({
+      rulesDirectory: path.join(__dirname, 'rules'),
+      rules: {
+        'no-lazy-module-paths': [true],
+      },
+    }, {
+      includes: '**/*.ts',
+      silent: false,
+    }));
+  };
+};

packages/schematics/angular/migrations/update-8/update-lazy-module-paths_spec.ts

@@ -0,0 +1,85 @@
+/**
+ * @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 { getSystemPath, normalize, virtualFs } from '@angular-devkit/core';
+import { TempScopedNodeJsSyncHost } from '@angular-devkit/core/node/testing';
+import { HostTree } from '@angular-devkit/schematics';
+import { SchematicTestRunner, UnitTestTree } from '@angular-devkit/schematics/testing';
+
+describe('Migration to version 8', () => {
+  const schematicRunner = new SchematicTestRunner(
+    'migrations',
+    require.resolve('../migration-collection.json'),
+  );
+
+  let tree: UnitTestTree;
+  let host: TempScopedNodeJsSyncHost;
+
+  const lazyRoutePath = normalize('src/lazy-route.ts');
+  const lazyRoute = virtualFs.stringToFileBuffer(`
+    import { Route } from '@angular/router';
+    const routes: Array<Route> = [
+      {
+        path: '',
+        loadChildren: './lazy/lazy.module#LazyModule'
+      }
+    ];
+  `);
+
+  const lazyChildRoute = virtualFs.stringToFileBuffer(`
+    import { Route } from '@angular/router';
+    const routes: Array<Route> = [
+      {
+        path: '',
+        children: [{
+          path: 'child',
+          loadChildren: './lazy/lazy.module#LazyModule'
+        }]
+      }
+    ];
+  `);
+
+  describe('Migration to import() style lazy routes', () => {
+    beforeEach(async () => {
+      host = new TempScopedNodeJsSyncHost();
+      tree = new UnitTestTree(new HostTree(host));
+      tree.create('/package.json', JSON.stringify({}));
+      process.chdir(getSystemPath(host.root));
+    });
+
+    it('should replace the module path string', async () => {
+      await host.write(lazyRoutePath, lazyRoute).toPromise();
+
+      schematicRunner.runSchematic('migration-08', {}, tree);
+      await schematicRunner.engine.executePostTasks().toPromise();
+
+      const routes = await host.read(lazyRoutePath)
+        .toPromise()
+        .then(virtualFs.fileBufferToString);
+
+      expect(routes).not.toContain('./lazy/lazy.module#LazyModule');
+      expect(routes).toContain(
+        `loadChildren: () => import('./lazy/lazy.module').then(m => m.LazyModule)`);
+    });
+
+    it('should replace the module path string in a child path', async () => {
+      await host.write(lazyRoutePath, lazyChildRoute).toPromise();
+
+      schematicRunner.runSchematic('migration-08', {}, tree);
+      await schematicRunner.engine.executePostTasks().toPromise();
+
+      const routes = await host.read(lazyRoutePath)
+        .toPromise()
+        .then(virtualFs.fileBufferToString);
+
+      expect(routes).not.toContain('./lazy/lazy.module#LazyModule');
+
+      expect(routes).toContain(
+        `loadChildren: () => import('./lazy/lazy.module').then(m => m.LazyModule)`);
+    });
+  });
+});

packages/schematics/angular/package.json

@@ -9,6 +9,7 @@
   ],
   "schematics": "./collection.json",
   "dependencies": {
+    "@phenomnomnominal/tsquery": "3.0.0",
     "@angular-devkit/core": "0.0.0",
     "@angular-devkit/schematics": "0.0.0"
   }

yarn.lock

@@ -221,6 +221,13 @@
   resolved "https://registry.yarnpkg.com/@ngtools/json-schema/-/json-schema-1.1.0.tgz#c3a0c544d62392acc2813a42c8a0dc6f58f86922"
   integrity sha1-w6DFRNYjkqzCgTpCyKDcb1j4aSI=
 
+"@phenomnomnominal/tsquery@3.0.0":
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/@phenomnomnominal/tsquery/-/tsquery-3.0.0.tgz#6f2f4dbf6304ff52b12cc7a5b979f20c3794a22a"
+  integrity sha512-SW8lKitBHWJ9fAYkJ9kJivuctwNYCh3BUxLdH0+XiR1GPBiu+7qiZzh8p8jqlj1LgVC1TbvfNFroaEsmYlL8Iw==
+  dependencies:
+    esquery "^1.0.1"
+
 "@sindresorhus/is@^0.14.0":
   version "0.14.0"
   resolved "https://registry.yarnpkg.com/@sindresorhus/is/-/is-0.14.0.tgz#9fb3a3cf3132328151f353de4632e01e52102bea"
@@ -3341,6 +3348,13 @@ esprima@^4.0.0:
   resolved "https://registry.yarnpkg.com/esprima/-/esprima-4.0.1.tgz#13b04cdb3e6c5d19df91ab6987a8695619b0aa71"
   integrity sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==
 
+esquery@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/esquery/-/esquery-1.0.1.tgz#406c51658b1f5991a5f9b62b1dc25b00e3e5c708"
+  integrity sha512-SmiyZ5zIWH9VM+SRUReLS5Q8a7GxtRdxEBVZpm98rJM7Sb+A9DVCndXfkeFUd3byderg+EbDkfnevfCwynWaNA==
+  dependencies:
+    estraverse "^4.0.0"
+
 esrecurse@^4.1.0:
   version "4.2.1"
   resolved "https://registry.yarnpkg.com/esrecurse/-/esrecurse-4.2.1.tgz#007a3b9fdbc2b3bb87e4879ea19c92fdbd3942cf"
@@ -3353,7 +3367,7 @@ estraverse@^1.9.1:
   resolved "https://registry.yarnpkg.com/estraverse/-/estraverse-1.9.3.tgz#af67f2dc922582415950926091a4005d29c9bb44"
   integrity sha1-r2fy3JIlgkFZUJJgkaQAXSnJu0Q=
 
-estraverse@^4.1.0, estraverse@^4.1.1, estraverse@^4.2.0:
+estraverse@^4.0.0, estraverse@^4.1.0, estraverse@^4.1.1, estraverse@^4.2.0:
   version "4.2.0"
   resolved "https://registry.yarnpkg.com/estraverse/-/estraverse-4.2.0.tgz#0dee3fed31fcd469618ce7342099fc1afa0bdb13"
   integrity sha1-De4/7TH81GlhjOc0IJn8GvoL2xM=