Added handling mapping types

Fixes #15

Author: timocov

src/transformer.ts

@@ -286,12 +286,22 @@ function createTransformerFactory(program: ts.Program, options?: Partial<RenameO
 
 		// tslint:disable-next-line:cyclomatic-complexity
 		function isTypePropertyExternal(type: ts.Type, typePropertyName: string): boolean {
+			const symbol = type.getSymbol();
+
 			if (type.flags & ts.TypeFlags.Object) {
 				const objectType = type as ts.ObjectType;
 				// treat any tuple property as "external"
 				if (objectType.objectFlags & ts.ObjectFlags.Tuple) {
 					return true;
 				}
+
+				// because of we can't get where a property come from in mapped types
+				// let's check the whole its type explicitly
+				// thus let's treat any property of a mapped type as "external" if its parent type is external
+				// perhaps it would be awesome to handle exactly property we have, but ¯\_(ツ)_/¯
+				if ((objectType.objectFlags & ts.ObjectFlags.Mapped) && symbol !== undefined && getSymbolVisibilityType(symbol) === VisibilityType.External) {
+					return true;
+				}
 			}
 
 			if (type.isUnionOrIntersection()) {
@@ -301,7 +311,6 @@ function createTransformerFactory(program: ts.Program, options?: Partial<RenameO
 				}
 			}
 
-			const symbol = type.getSymbol();
 			if (symbol !== undefined) {
 				const declarations = getDeclarationsForSymbol(symbol);
 				for (const declaration of declarations) {

tests/test-cases/exported-mapped-types/input.ts

@@ -0,0 +1,24 @@
+type TestKey = 'a';
+
+export type MappedType = {
+	[P in TestKey]?: {};
+};
+
+export interface Interface {
+	a?: {};
+}
+
+class TestMappedClass {
+	private interfaced: Interface = {
+		a: {},
+	};
+
+	private mapped: MappedType = {
+		a: {},
+	};
+
+	public constructor() {
+		this.interfaced.a = {};
+		this.mapped.a = {};
+	}
+}

tests/test-cases/exported-mapped-types/output.js

@@ -0,0 +1,15 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+var TestMappedClass = /** @class */ (function () {
+    function TestMappedClass() {
+        this._private_interfaced = {
+            a: {},
+        };
+        this._private_mapped = {
+            a: {},
+        };
+        this._private_interfaced.a = {};
+        this._private_mapped.a = {};
+    }
+    return TestMappedClass;
+}());

tests/test-cases/mark-mapped-types-as-public-with-jsdoc/input.ts

@@ -0,0 +1,16 @@
+type TestKey = 'a' | 'b';
+
+/** @public */
+type TestMappedType = {
+	[P in TestKey]?: {};
+};
+
+class TestMappedClass {
+	private mapped: TestMappedType = {
+		a: {},
+	};
+
+	public constructor() {
+		this.mapped.a = {};
+	}
+}

tests/test-cases/mark-mapped-types-as-public-with-jsdoc/output.js

@@ -0,0 +1,9 @@
+var TestMappedClass = /** @class */ (function () {
+    function TestMappedClass() {
+        this._private_mapped = {
+            a: {},
+        };
+        this._private_mapped.a = {};
+    }
+    return TestMappedClass;
+}());