feat(core): add undecorated classes with decorated fields schematic

packages/core/schematics/BUILD.bazel

@@ -14,6 +14,7 @@ npm_package(
         "//packages/core/schematics/migrations/renderer-to-renderer2",
         "//packages/core/schematics/migrations/static-queries",
         "//packages/core/schematics/migrations/template-var-assignment",
+        "//packages/core/schematics/migrations/undecorated-classes-with-decorated-fields",
         "//packages/core/schematics/migrations/undecorated-classes-with-di",
     ],
 )

packages/core/schematics/migrations.json

@@ -24,6 +24,11 @@
       "version": "9-beta",
       "description": "Decorates undecorated base classes of directives/components that use dependency injection. Copies metadata from base classes to derived directives/components/pipes that are not decorated.",
       "factory": "./migrations/undecorated-classes-with-di/index"
+    },
+    "migration-v9-undecorated-classes-with-decorated-fields": {
+      "version": "9-beta",
+      "description": "Adds an Angular decorator to undecorated classes that have decorated fields",
+      "factory": "./migrations/undecorated-classes-with-decorated-fields/index"
     }
   }
 }

packages/core/schematics/migrations/google3/BUILD.bazel

@@ -11,6 +11,7 @@ ts_library(
         "//packages/core/schematics/migrations/renderer-to-renderer2",
         "//packages/core/schematics/migrations/static-queries",
         "//packages/core/schematics/migrations/template-var-assignment",
+        "//packages/core/schematics/migrations/undecorated-classes-with-decorated-fields",
         "//packages/core/schematics/utils",
         "//packages/core/schematics/utils/tslint",
         "@npm//tslint",

packages/core/schematics/migrations/google3/undecoratedClassesWithDecoratedFieldsRule.ts

@@ -0,0 +1,56 @@
+/**
+ * @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 {Replacement, RuleFailure, Rules} from 'tslint';
+import * as ts from 'typescript';
+
+import {FALLBACK_DECORATOR, addImport, getNamedImports, getUndecoratedClassesWithDecoratedFields, hasNamedImport} from '../undecorated-classes-with-decorated-fields/utils';
+
+
+
+/**
+ * TSLint rule that adds an Angular decorator to classes that have Angular field decorators.
+ * https://hackmd.io/vuQfavzfRG6KUCtU7oK_EA
+ */
+export class Rule extends Rules.TypedRule {
+  applyWithProgram(sourceFile: ts.SourceFile, program: ts.Program): RuleFailure[] {
+    const typeChecker = program.getTypeChecker();
+    const printer = ts.createPrinter();
+    const classes = getUndecoratedClassesWithDecoratedFields(sourceFile, typeChecker);
+
+    return classes.map((current, index) => {
+      const {classDeclaration: declaration, importDeclaration} = current;
+      const name = declaration.name;
+
+      // Set the class identifier node (if available) as the failing node so IDEs don't highlight
+      // the entire class with red. This is similar to how errors are shown for classes in other
+      // cases like an interface not being implemented correctly.
+      const start = (name || declaration).getStart();
+      const end = (name || declaration).getEnd();
+      const fixes = [Replacement.appendText(declaration.getStart(), `@${FALLBACK_DECORATOR}()\n`)];
+
+      // If it's the first class that we're processing in this file, add `Directive` to the imports.
+      if (index === 0 && !hasNamedImport(importDeclaration, FALLBACK_DECORATOR)) {
+        const namedImports = getNamedImports(importDeclaration);
+
+        if (namedImports) {
+          fixes.push(new Replacement(
+              namedImports.getStart(), namedImports.getWidth(),
+              printer.printNode(
+                  ts.EmitHint.Unspecified, addImport(namedImports, FALLBACK_DECORATOR),
+                  sourceFile)));
+        }
+      }
+
+      return new RuleFailure(
+          sourceFile, start, end,
+          'Classes with decorated fields must have an Angular decorator as well.',
+          'undecorated-classes-with-decorated-fields', fixes);
+    });
+  }
+}

packages/core/schematics/migrations/undecorated-classes-with-decorated-fields/BUILD.bazel

@@ -0,0 +1,18 @@
+load("//tools:defaults.bzl", "ts_library")
+
+ts_library(
+    name = "undecorated-classes-with-decorated-fields",
+    srcs = glob(["**/*.ts"]),
+    tsconfig = "//packages/core/schematics:tsconfig.json",
+    visibility = [
+        "//packages/core/schematics:__pkg__",
+        "//packages/core/schematics/migrations/google3:__pkg__",
+        "//packages/core/schematics/test:__pkg__",
+    ],
+    deps = [
+        "//packages/core/schematics/utils",
+        "@npm//@angular-devkit/schematics",
+        "@npm//@types/node",
+        "@npm//typescript",
+    ],
+)

packages/core/schematics/migrations/undecorated-classes-with-decorated-fields/README.md

@@ -0,0 +1,23 @@
+## Undecorated classes with decorated fields migration
+
+Automatically adds a `Directive` decorator to undecorated classes that have fields with Angular
+decorators. Also adds the relevant imports, if necessary.
+
+#### Before
+```ts
+import { Input } from '@angular/core';
+
+export class Base {
+  @Input() isActive: boolean;
+}
+```
+
+#### After
+```ts
+import { Input, Directive } from '@angular/core';
+
+@Directive()
+export class Base {
+  @Input() isActive: boolean;
+}
+```

packages/core/schematics/migrations/undecorated-classes-with-decorated-fields/index.ts

@@ -0,0 +1,93 @@
+/**
+ * @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, SchematicsException, Tree} from '@angular-devkit/schematics';
+import {dirname, relative} from 'path';
+import * as ts from 'typescript';
+
+import {getProjectTsConfigPaths} from '../../utils/project_tsconfig_paths';
+import {parseTsconfigFile} from '../../utils/typescript/parse_tsconfig';
+import {FALLBACK_DECORATOR, addImport, getNamedImports, getUndecoratedClassesWithDecoratedFields, hasNamedImport} from './utils';
+
+
+/**
+ * Migration that adds an Angular decorator to classes that have Angular field decorators.
+ * https://hackmd.io/vuQfavzfRG6KUCtU7oK_EA
+ */
+export default function(): Rule {
+  return (tree: Tree, context: SchematicContext) => {
+    const {buildPaths, testPaths} = getProjectTsConfigPaths(tree);
+    const basePath = process.cwd();
+    const allPaths = [...buildPaths, ...testPaths];
+    const logger = context.logger;
+
+    logger.info('------ Undecorated classes with decorated fields migration ------');
+    logger.info(
+        'As of Angular 9, it is no longer supported to have Angular field ' +
+        'decorators on a class that does not have an Angular decorator.');
+
+    if (!allPaths.length) {
+      throw new SchematicsException(
+          'Could not find any tsconfig file. Cannot add an Angular decorator to undecorated classes.');
+    }
+
+    for (const tsconfigPath of allPaths) {
+      runUndecoratedClassesMigration(tree, tsconfigPath, basePath);
+    }
+  };
+}
+
+function runUndecoratedClassesMigration(tree: Tree, tsconfigPath: string, basePath: string) {
+  const parsed = parseTsconfigFile(tsconfigPath, dirname(tsconfigPath));
+  const host = ts.createCompilerHost(parsed.options, true);
+
+  // We need to overwrite the host "readFile" method, as we want the TypeScript
+  // program to be based on the file contents in the virtual file tree. Otherwise
+  // if we run the migration for multiple tsconfig files which have intersecting
+  // source files, it can end up updating them multiple times.
+  host.readFile = fileName => {
+    const buffer = tree.read(relative(basePath, fileName));
+    // Strip BOM as otherwise TSC methods (Ex: getWidth) will return an offset which
+    // which breaks the CLI UpdateRecorder.
+    // See: https://github.com/angular/angular/pull/30719
+    return buffer ? buffer.toString().replace(/^\uFEFF/, '') : undefined;
+  };
+
+  const program = ts.createProgram(parsed.fileNames, parsed.options, host);
+  const typeChecker = program.getTypeChecker();
+  const printer = ts.createPrinter();
+  const sourceFiles = program.getSourceFiles().filter(
+      file => !file.isDeclarationFile && !program.isSourceFileFromExternalLibrary(file));
+
+  sourceFiles.forEach(sourceFile => {
+    const update = tree.beginUpdate(relative(basePath, sourceFile.fileName));
+    const classes = getUndecoratedClassesWithDecoratedFields(sourceFile, typeChecker);
+
+    classes.forEach((current, index) => {
+      // If it's the first class that we're processing in this file, add `Directive` to the imports.
+      if (index === 0 && !hasNamedImport(current.importDeclaration, FALLBACK_DECORATOR)) {
+        const namedImports = getNamedImports(current.importDeclaration);
+
+        if (namedImports) {
+          update.remove(namedImports.getStart(), namedImports.getWidth());
+          update.insertRight(
+              namedImports.getStart(),
+              printer.printNode(
+                  ts.EmitHint.Unspecified, addImport(namedImports, FALLBACK_DECORATOR),
+                  sourceFile));
+        }
+      }
+
+      // We don't need to go through the AST to insert the decorator, because the change
+      // is pretty basic. Also this has a better chance of preserving the user's formatting.
+      update.insertLeft(current.classDeclaration.getStart(), `@${FALLBACK_DECORATOR}()\n`);
+    });
+
+    tree.commitUpdate(update);
+  });
+}

packages/core/schematics/migrations/undecorated-classes-with-decorated-fields/utils.ts

@@ -0,0 +1,71 @@
+/**
+ * @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 ts from 'typescript';
+import {getAngularDecorators} from '../../utils/ng_decorators';
+
+/** Name of the decorator that should be added to undecorated classes. */
+export const FALLBACK_DECORATOR = 'Directive';
+
+/** Finds all of the undecorated classes that have decorated fields within a file. */
+export function getUndecoratedClassesWithDecoratedFields(
+    sourceFile: ts.SourceFile, typeChecker: ts.TypeChecker) {
+  const classes: UndecoratedClassWithDecoratedFields[] = [];
+
+  sourceFile.forEachChild(function walk(node: ts.Node) {
+    if (ts.isClassDeclaration(node) &&
+        (!node.decorators || !getAngularDecorators(typeChecker, node.decorators).length)) {
+      for (const member of node.members) {
+        const angularDecorators =
+            member.decorators && getAngularDecorators(typeChecker, member.decorators);
+
+        if (angularDecorators && angularDecorators.length) {
+          classes.push(
+              {classDeclaration: node, importDeclaration: angularDecorators[0].importNode});
+          return;
+        }
+      }
+    }
+
+    node.forEachChild(walk);
+  });
+
+  return classes;
+}
+
+/** Checks whether an import declaration has an import with a certain name. */
+export function hasNamedImport(declaration: ts.ImportDeclaration, symbolName: string): boolean {
+  const namedImports = getNamedImports(declaration);
+
+  if (namedImports) {
+    return namedImports.elements.some(element => {
+      const {name, propertyName} = element;
+      return propertyName ? propertyName.text === symbolName : name.text === symbolName;
+    });
+  }
+
+  return false;
+}
+
+/** Extracts the NamedImports node from an import declaration. */
+export function getNamedImports(declaration: ts.ImportDeclaration): ts.NamedImports|null {
+  const namedBindings = declaration.importClause && declaration.importClause.namedBindings;
+  return (namedBindings && ts.isNamedImports(namedBindings)) ? namedBindings : null;
+}
+
+/** Adds a new import to a NamedImports node. */
+export function addImport(declaration: ts.NamedImports, symbolName: string) {
+  return ts.updateNamedImports(declaration, [
+    ...declaration.elements, ts.createImportSpecifier(undefined, ts.createIdentifier(symbolName))
+  ]);
+}
+
+interface UndecoratedClassWithDecoratedFields {
+  classDeclaration: ts.ClassDeclaration;
+  importDeclaration: ts.ImportDeclaration;
+}

packages/core/schematics/test/BUILD.bazel

@@ -14,6 +14,7 @@ ts_library(
         "//packages/core/schematics/migrations/renderer-to-renderer2",
         "//packages/core/schematics/migrations/static-queries",
         "//packages/core/schematics/migrations/template-var-assignment",
+        "//packages/core/schematics/migrations/undecorated-classes-with-decorated-fields",
         "//packages/core/schematics/migrations/undecorated-classes-with-di",
         "//packages/core/schematics/utils",
         "@npm//@angular-devkit/core",