feat(isMatching): Typecheck pattern when using isMatching wth 2 param…

…eters

src/is-matching.ts

@@ -33,10 +33,10 @@ export function isMatching<const p extends Pattern<unknown>>(
  *    return input.name
  *  }
  */
-export function isMatching<const p extends Pattern<unknown>>(
-  pattern: p,
-  value: unknown
-): value is P.infer<p>;
+export function isMatching<const T, const P extends P.Pattern<NoInfer<T>>>(
+  pattern: P,
+  value: T
+): value is P.infer<P>;
 
 export function isMatching<const p extends Pattern<any>>(
   ...args: [pattern: p, value?: any]

tests/is-matching.test.ts

@@ -56,11 +56,11 @@ describe('isMatching', () => {
     }
   });
 
-  it('type inference should be precise without `as const`', () => {
-    type Pizza = { type: 'pizza'; topping: string };
-    type Sandwich = { type: 'sandwich'; condiments: string[] };
-    type Food = Pizza | Sandwich;
+  type Pizza = { type: 'pizza'; topping: string };
+  type Sandwich = { type: 'sandwich'; condiments: string[] };
+  type Food = Pizza | Sandwich;
 
+  it('type inference should be precise without `as const`', () => {
     const food = { type: 'pizza', topping: 'cheese' } as Food;
 
     const isPizza = isMatching({ type: 'pizza' });
@@ -77,4 +77,16 @@ describe('isMatching', () => {
       throw new Error('Expected food to match the pizza pattern!');
     }
   });
+
+  it('should reject invalid pattern when two parameters are passed', () => {
+    const food = { type: 'pizza', topping: 'cheese' } as Food;
+
+    isMatching(
+      {
+        // @ts-expect-error
+        type: 'oops',
+      },
+      food
+    );
+  });
 });

tests/matcher-protocol.test.ts

@@ -26,7 +26,8 @@ describe('matcher protocol', () => {
         match: (input) => {
           return {
             matched:
-              input instanceof Some && isMatching<any>(this.value, input.value),
+              input instanceof Some &&
+              isMatching<any, any>(this.value, input.value),
           };
         },
       };