fix #8.

dist/src/Substitute.d.ts

@@ -2,6 +2,6 @@ import { ObjectSubstitute, OmitProxyMethods, DisabledSubstituteObject } from "./
 export declare const HandlerKey: unique symbol;
 export declare const AreProxiesDisabledKey: unique symbol;
 export declare class Substitute {
-    static for<T>(): ObjectSubstitute<OmitProxyMethods<T>, T>;
+    static for<T>(): ObjectSubstitute<OmitProxyMethods<T>, T> & T;
     static disableFor<T extends ObjectSubstitute<OmitProxyMethods<any>>>(substitute: T): DisabledSubstituteObject<T>;
 }

spec/issues/8.test.ts

@@ -0,0 +1,40 @@
+import Substitute from "../../src/Index";
+import test from 'ava';
+
+class ClassA {
+	constructor(){}
+
+	methodA(): string {
+		return 'abc'
+	}
+}
+
+class ClassB {
+	constructor(
+		private classA: ClassA
+	) {}
+
+	methodB(): string {
+		return this.classA.methodA();
+	}
+
+	methodB2(): string {
+		return 'def'
+	}
+}
+
+class ClassC {
+	constructor(
+		private classB: ClassB
+	) {}
+
+	methodC(): string {
+		return this.classB.methodB2();
+	}
+}
+
+test('issue 9: can record method with 0 arguments', async t => {
+    const classBMock = Substitute.for<ClassB>();
+    const classC = new ClassC(classBMock);
+    t.not(classC, null);
+});

src/Substitute.ts

@@ -5,7 +5,7 @@ export const HandlerKey = Symbol();
 export const AreProxiesDisabledKey = Symbol();
 
 export class Substitute {
-    static for<T>(): ObjectSubstitute<OmitProxyMethods<T>, T> {
+    static for<T>(): ObjectSubstitute<OmitProxyMethods<T>, T> & T {
         const objectContext = new Context();
         return objectContext.rootProxy;
     }