Added ignoreDecorated option to ignore "decorated" fields and not to rename them

Fixes #31

Author: timocov

README.md

@@ -225,6 +225,13 @@ const colors: Record<string, string> = {
 // ...
 ```
 
+### ignoreDecorated
+
+*Default: `false`*
+
+Whether fields that were decorated should be renamed.
+A field is treated as "decorated" if itself or any its parent (on type level) has a decorator.
+
 ## How to use the custom transformer
 
 Unfortunately, TypeScript itself does not currently provide any easy way to use custom transformers (see <https://github.com/Microsoft/TypeScript/issues/14419>).

src/transformer.ts

@@ -11,6 +11,7 @@ import {
 	isSymbolClassMember,
 	splitTransientSymbol,
 	getClassOfMemberSymbol,
+	hasDecorators,
 } from './typescript-helpers';
 
 export interface RenameOptions {
@@ -43,13 +44,20 @@ export interface RenameOptions {
 	 * @example ''
 	 */
 	publicJSDocTag: string;
+
+	/**
+	 * Whether fields that were decorated should be renamed.
+	 * A field is treated as "decorated" if itself or any its parent (on type level) has a decorator.
+	 */
+	ignoreDecorated: boolean;
 }
 
 const defaultOptions: RenameOptions = {
 	entrySourceFiles: [],
 	privatePrefix: '_private_',
 	internalPrefix: '_internal_',
 	publicJSDocTag: 'public',
+	ignoreDecorated: false,
 };
 
 const enum VisibilityType {
@@ -444,20 +452,22 @@ function createTransformerFactory(program: ts.Program, options?: Partial<RenameO
 				return putToCache(nodeSymbol, VisibilityType.External);
 			}
 
-			if (isPrivateClassMember(nodeSymbol)) {
-				return putToCache(nodeSymbol, VisibilityType.Private);
-			}
-
 			if (nodeSymbol.escapedName === 'prototype') {
 				// accessing to prototype
 				return putToCache(nodeSymbol, VisibilityType.External);
 			}
 
-			if (fullOptions.publicJSDocTag.length !== 0) {
+			if (fullOptions.publicJSDocTag.length !== 0 || fullOptions.ignoreDecorated) {
 				for (const declaration of symbolDeclarations) {
 					let currentNode: ts.Node = declaration;
 					while (!ts.isSourceFile(currentNode)) {
-						if (getNodeJSDocComment(currentNode).includes(`@${fullOptions.publicJSDocTag}`)) {
+						if (fullOptions.publicJSDocTag.length !== 0
+							&& getNodeJSDocComment(currentNode).includes(`@${fullOptions.publicJSDocTag}`)
+						) {
+							return putToCache(nodeSymbol, VisibilityType.External);
+						}
+
+						if (fullOptions.ignoreDecorated && hasDecorators(currentNode)) {
 							return putToCache(nodeSymbol, VisibilityType.External);
 						}
 
@@ -466,6 +476,10 @@ function createTransformerFactory(program: ts.Program, options?: Partial<RenameO
 				}
 			}
 
+			if (isPrivateClassMember(nodeSymbol)) {
+				return putToCache(nodeSymbol, VisibilityType.Private);
+			}
+
 			if (exportsSymbolTree.isSymbolAccessibleFromExports(nodeSymbol)) {
 				return putToCache(nodeSymbol, VisibilityType.External);
 			}

src/typescript-helpers.ts

@@ -145,6 +145,23 @@ export function hasModifier(node: ts.Node, modifier: ts.SyntaxKind): boolean {
 	return getModifiers(node).some(mod => mod.kind === modifier);
 }
 
+function getDecorators(node: ts.Node): readonly unknown[] {
+	if (isBreakingTypeScriptApi(ts)) {
+		if (!ts.canHaveDecorators(node)) {
+			return [];
+		}
+
+		return ts.getDecorators(node) || [];
+	}
+
+	// eslint-disable-next-line deprecation/deprecation
+	return node.decorators || [];
+}
+
+export function hasDecorators(node: ts.Node): boolean {
+	return getDecorators(node).length !== 0;
+}
+
 export function isConstructorParameter(node: ts.Node): node is ts.ParameterDeclaration {
 	return ts.isParameter(node) &&
 		ts.isConstructorDeclaration(node.parent as ts.Node) &&

tests/functional-test-cases.ts

@@ -74,6 +74,7 @@ describe(`Functional tests for typescript v${ts.versionMajorMinor}`, () => {
 			const program = ts.createProgram({
 				rootNames: [testCase.inputFileName],
 				options: {
+					experimentalDecorators: true,
 					target: ts.ScriptTarget.ES5,
 				},
 			});
@@ -89,6 +90,7 @@ describe(`Functional tests for typescript v${ts.versionMajorMinor}`, () => {
 					privatePrefix: '_private_',
 					internalPrefix: '_internal_',
 					publicJSDocTag: 'public',
+					ignoreDecorated: true,
 				}
 			);
 

tests/test-cases/decorators/input.ts

@@ -0,0 +1,10 @@
+declare const foo: any;
+
+class Foo {
+	@foo private field = 1;
+}
+
+@foo
+class Foo2 {
+	private field = 1;
+}

tests/test-cases/decorators/output.js

@@ -0,0 +1,24 @@
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var Foo = /** @class */ (function () {
+    function Foo() {
+        this.field = 1;
+    }
+    __decorate([
+        foo
+    ], Foo.prototype, "field", void 0);
+    return Foo;
+}());
+var Foo2 = /** @class */ (function () {
+    function Foo2() {
+        this.field = 1;
+    }
+    Foo2 = __decorate([
+        foo
+    ], Foo2);
+    return Foo2;
+}());

tests/test-cases/tsconfig.json

@@ -0,0 +1,7 @@
+{
+	"extends": "../../tsconfig.base.json",
+	"compilerOptions": {
+		"noUnusedLocals": false,
+		"experimentalDecorators": true
+	}
+}