feat(core): add undecorated classes with decorated fields schematic (#32130)

Adds a schematic that adds a `Directive` decorator to undecorated classes that have fields that use Angular decorators.

PR Close #32130

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);
+    });
+  }
+}