Change inference order for ObjectSubstituteTransformation. Fixes #24. (#56)

Author: ulrichsg

spec/issues/24.test.ts

@@ -0,0 +1,22 @@
+import test from 'ava';
+
+import { Substitute } from '../../src/index';
+
+interface IHaveOptionalArguments {
+  onlyOptional(a?: number): number;
+  mandatoryAndOptional(a: number, b?: number): number;
+}
+test('issue 24 - Mocked method arguments not allowed when verifying method was called', async t => {
+  const substitute = Substitute.for<IHaveOptionalArguments>();
+  substitute.onlyOptional().returns(1);
+  substitute.onlyOptional(2).returns(2);
+
+  t.is(substitute.onlyOptional(), 1);
+  t.is(substitute.onlyOptional(2), 2);
+
+  substitute.mandatoryAndOptional(1).returns(1);
+  substitute.mandatoryAndOptional(1, 2).returns(2);
+
+  t.is(substitute.mandatoryAndOptional(1), 1);
+  t.is(substitute.mandatoryAndOptional(1, 2), 2);
+});

src/Transformations.ts

@@ -36,13 +36,13 @@ type TerminatingObject<T> = {
 
 type ObjectSubstituteTransformation<T extends Object> = {
     [P in keyof T]:
-    T[P] extends () => infer R ? NoArgumentFunctionSubstitute<R> :
     T[P] extends (...args: infer F) => infer R ? FunctionSubstitute<F, R> :
+    T[P] extends () => infer R ? NoArgumentFunctionSubstitute<R> :
     PropertySubstitute<T[P]>;
 }
 
 type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>;
 
 export type OmitProxyMethods<T extends any> = Omit<T, 'mimick'|'received'|'didNotReceive'>;
 
-export type DisabledSubstituteObject<T> = T extends ObjectSubstitute<OmitProxyMethods<infer K>, infer K> ? K : never;
+export type DisabledSubstituteObject<T> = T extends ObjectSubstitute<OmitProxyMethods<infer K>, infer K> ? K : never;