refactor(schematics): avoid typescript version conflicts

The Angular Material schematics parse TypeScript sources files and pass the AST to the `@schematics/angular` package which defined an explicit dependency on `typescript`. Since we currently just always require the flattened `typescript` dependency (`node_modules/typescript`), there could be either no TypeScript version or a different TypeScript version that causes the AST operations of the `@schematics/angular` utility functions to not work properly (e.g. different `SyntaxKind` ids)

We should primarily try to load the same TypeScript version that has been shipped with the `@schematics/angular`. If that one couldn't be found, fall back to the top level `typescript` version.

Author: devversion

.circleci/config.yml

@@ -47,7 +47,11 @@ jobs:
           <<: *post_checkout
       - restore_cache:
           key: *cache_key
-      - run: echo "Temporarily disabled until Bazel setup can be fixed"
+
+      - run: bazel run @nodejs//:npm install
+        # TODO(jelbourn): Update this command to run all tests if the Bazel issues have been fixed.
+      - run: bazel test src/lib/schematics:unit_tests
+
       - save_cache:
           key: *cache_key
           paths:

src/lib/schematics/utils/ast.ts

@@ -12,11 +12,11 @@ import {InsertChange} from '@schematics/angular/utility/change';
 import {getWorkspace, WorkspaceProject} from '@schematics/angular/utility/config';
 import {findModuleFromOptions as internalFindModule} from '@schematics/angular/utility/find-module';
 import {getAppModulePath} from '@schematics/angular/utility/ng-ast-utils';
-import * as ts from 'typescript';
+import {ts} from './version-agnostic-typescript';
 
 
 /** Reads file given path and returns TypeScript source file. */
-export function getSourceFile(host: Tree, path: string): ts.SourceFile {
+export function getSourceFile(host: Tree, path: string) {
   const buffer = host.read(path);
   if (!buffer) {
     throw new SchematicsException(`Could not find file for path: ${path}`);
@@ -48,9 +48,7 @@ export function addModuleImportToModule(
     throw new SchematicsException(`Module not found: ${modulePath}`);
   }
 
-  // TODO: cast to any, because the types for ts.SourceFile
-  // aren't compatible with `strictFunctionTypes`.
-  const changes = addImportToModule(moduleSource as any, modulePath, moduleName, src);
+  const changes = addImportToModule(moduleSource, modulePath, moduleName, src);
   const recorder = host.beginUpdate(modulePath);
 
   changes.forEach((change) => {

src/lib/schematics/utils/build-component.ts

@@ -38,17 +38,16 @@ import {buildDefaultPath} from '@schematics/angular/utility/project';
 import {validateHtmlSelector, validateName} from '@schematics/angular/utility/validation';
 import {readFileSync} from 'fs';
 import {dirname, join, resolve} from 'path';
-import * as ts from 'typescript';
+import {ts} from './version-agnostic-typescript';
 import {getDefaultComponentOptions} from './schematic-options';
 
-function readIntoSourceFile(host: Tree, modulePath: string): ts.SourceFile {
+function readIntoSourceFile(host: Tree, modulePath: string) {
   const text = host.read(modulePath);
   if (text === null) {
     throw new SchematicsException(`File ${modulePath} does not exist.`);
   }
-  const sourceText = text.toString('utf-8');
 
-  return ts.createSourceFile(modulePath, sourceText, ts.ScriptTarget.Latest, true);
+  return ts.createSourceFile(modulePath, text.toString('utf-8'), ts.ScriptTarget.Latest, true);
 }
 
 function addDeclarationToNgModule(options: ComponentOptions): Rule {
@@ -67,9 +66,8 @@ function addDeclarationToNgModule(options: ComponentOptions): Rule {
     const relativePath = buildRelativePath(modulePath, componentPath);
     const classifiedName = strings.classify(`${options.name}Component`);
 
-    // TODO: cast to any, because the types for ts.SourceFile
-    // aren't compatible with `strictFunctionTypes`.
-    const declarationChanges = addDeclarationToModule(source as any,
+    const declarationChanges = addDeclarationToModule(
+      source,
       modulePath,
       classifiedName,
       relativePath);
@@ -87,9 +85,7 @@ function addDeclarationToNgModule(options: ComponentOptions): Rule {
       const source = readIntoSourceFile(host, modulePath);
       const exportRecorder = host.beginUpdate(modulePath);
 
-      // TODO: cast to any, because the types for ts.SourceFile
-      // aren't compatible with `strictFunctionTypes`.
-      const exportChanges = addExportToModule(source as any, modulePath,
+      const exportChanges = addExportToModule(source, modulePath,
         strings.classify(`${options.name}Component`),
         relativePath);
 
@@ -106,10 +102,9 @@ function addDeclarationToNgModule(options: ComponentOptions): Rule {
       const source = readIntoSourceFile(host, modulePath);
       const entryComponentRecorder = host.beginUpdate(modulePath);
 
-      // TODO: cast to any, because the types for ts.SourceFile
-      // aren't compatible with `strictFunctionTypes`.
       const entryComponentChanges = addEntryComponentToModule(
-        source as any, modulePath,
+        source,
+        modulePath,
         strings.classify(`${options.name}Component`),
         relativePath);
 

src/lib/schematics/utils/version-agnostic-typescript.ts

@@ -0,0 +1,33 @@
+/**
+ * @license
+ * Copyright Google LLC 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
+ */
+
+/** This is just a type import and won't be generated in the release output. */
+import typescript = require('@schematics/angular/node_modules/typescript');
+
+/**
+ * This is an agnostic re-export of TypeScript. Depending on the context, this module file will
+ * return the TypeScript version that is being shipped within the `@schematics/angular` package,
+ * or fall back to the TypeScript version that has been flattened in the node modules.
+ *
+ * This is necessary because we parse TypeScript files and pass the resolved AST to the
+ * `@schematics/angular` package which might have a different TypeScript version installed.
+ */
+let ts: typeof typescript;
+
+try {
+  ts = require('@schematics/angular/node_modules/typescript');
+} catch {
+  try {
+    ts = require('typescript');
+  } catch {
+    throw new Error('Error: Could not find TypeScript for the Angular Material schematics. ' +
+      'Please report an issue on the Angular Material repository.');
+  }
+}
+
+export {ts};