Fixed handling class fields with declare keyword

Fixes #32

Author: timocov

src/transformer.ts

@@ -12,6 +12,7 @@ import {
 	splitTransientSymbol,
 	getClassOfMemberSymbol,
 	hasDecorators,
+	hasModifier,
 } from './typescript-helpers';
 
 export interface RenameOptions {
@@ -452,6 +453,10 @@ function createTransformerFactory(program: ts.Program, options?: Partial<RenameO
 				return putToCache(nodeSymbol, VisibilityType.External);
 			}
 
+			if (symbolDeclarations.some((decl: ts.Declaration) => hasModifier(decl, ts.SyntaxKind.DeclareKeyword))) {
+				return putToCache(nodeSymbol, VisibilityType.External);
+			}
+
 			if (nodeSymbol.escapedName === 'prototype') {
 				// accessing to prototype
 				return putToCache(nodeSymbol, VisibilityType.External);

src/typescript-helpers.ts

@@ -209,6 +209,6 @@ interface BreakingTypeScriptApi {
 	getModifiers(node: ts.Node): readonly ts.Modifier[] | undefined;
 }
 
-function isBreakingTypeScriptApi(compiler: unknown): compiler is BreakingTypeScriptApi {
-	return 'canHaveDecorators' in ts;
+function isBreakingTypeScriptApi(compiler: object): compiler is BreakingTypeScriptApi {
+	return 'canHaveDecorators' in compiler;
 }

tests/functional-test-cases.ts

@@ -68,14 +68,52 @@ function checkDiagnosticsErrors(diagnostics: readonly ts.Diagnostic[]): void {
 	assert.strictEqual(diagnostics.length, 0, ts.formatDiagnostics(diagnostics, formatDiagnosticsHost).trim());
 }
 
+const enum Constants {
+	NoInputsWereFoundDiagnosticCode = 18003,
+}
+
+const parseConfigHost: ts.ParseConfigHost = {
+	useCaseSensitiveFileNames: ts.sys.useCaseSensitiveFileNames,
+	readDirectory: ts.sys.readDirectory,
+	fileExists: ts.sys.fileExists,
+	readFile: ts.sys.readFile,
+};
+
+function getCompilerOptions(configFileName: string): ts.CompilerOptions | null {
+	if (!fs.existsSync(configFileName)) {
+		return null;
+	}
+
+	const configParseResult = ts.readConfigFile(configFileName, ts.sys.readFile);
+
+	checkDiagnosticsErrors(configParseResult.error !== undefined ? [configParseResult.error] : []);
+
+	const compilerOptionsParseResult = ts.parseJsonConfigFileContent(
+		configParseResult.config,
+		parseConfigHost,
+		path.resolve(path.dirname(configFileName)),
+		undefined,
+		configFileName
+	);
+
+	// we don't want to raise an error if no inputs found in a config file
+	// because this error is mostly for CLI, but we'll pass an inputs in createProgram
+	const diagnostics = compilerOptionsParseResult.errors
+		.filter((d: ts.Diagnostic) => d.code !== Constants.NoInputsWereFoundDiagnosticCode);
+
+	checkDiagnosticsErrors(diagnostics);
+
+	return compilerOptionsParseResult.options;
+}
+
 describe(`Functional tests for typescript v${ts.versionMajorMinor}`, () => {
 	for (const testCase of getTestCases()) {
 		it(testCase.name, () => {
 			const program = ts.createProgram({
 				rootNames: [testCase.inputFileName],
 				options: {
-					experimentalDecorators: true,
 					target: ts.ScriptTarget.ES5,
+					...getCompilerOptions(path.join(testCase.inputFileName, '..', 'tsconfig.json')),
 				},
 			});
 

tests/test-cases/decorators/tsconfig.json

@@ -0,0 +1,5 @@
+{
+	"compilerOptions": {
+		"experimentalDecorators": true
+	}
+}

tests/test-cases/useDefineForClassFields-and-declare/input.ts

@@ -0,0 +1,9 @@
+class Class {
+	public declare publicField: number;
+	protected declare protectedField: number;
+	private declare privateField: number;
+
+	public method() {
+		console.log(this.publicField, this.protectedField, this.privateField);
+	}
+}

tests/test-cases/useDefineForClassFields-and-declare/output.js

@@ -0,0 +1,13 @@
+var Class = /** @class */ (function () {
+    function Class() {
+    }
+    Object.defineProperty(Class.prototype, "_internal_method", {
+        enumerable: false,
+        configurable: true,
+        writable: true,
+        value: function () {
+            console.log(this.publicField, this.protectedField, this.privateField);
+        }
+    });
+    return Class;
+}());

tests/test-cases/useDefineForClassFields-and-declare/tsconfig.json

@@ -0,0 +1,6 @@
+{
+	"compilerOptions": {
+		"target": "es5",
+		"useDefineForClassFields": true
+	}
+}