Improve type inference of createSelector. (#1758)

* Add function overloads to `createSelector` to improve type inference.

* Improve selector types

* Remove unnecessary overload from createSelector

.changeset/five-cats-compare.md

@@ -0,0 +1,5 @@
+---
+"solid-js": patch
+---
+
+Improve type inference of `createSelector`.

packages/solid/src/reactive/signal.ts

@@ -784,7 +784,7 @@ export type EqualityCheckerFunction<T, U> = (a: U, b: T) => boolean;
  *
  * @description https://www.solidjs.com/docs/latest/api#createselector
  */
-export function createSelector<T, U>(
+export function createSelector<T, U = T>(
   source: Accessor<T>,
   fn: EqualityCheckerFunction<T, U> = equalFn as TODO,
   options?: BaseOptions

packages/solid/test/signals.type-tests.ts

@@ -6,6 +6,7 @@ import {
   Accessor,
   on,
   createSignal,
+  createSelector,
   Signal,
   Setter
   // } from "../types/index";
@@ -710,6 +711,58 @@ const onMemo3 = createMemo(
 // @ts-expect-error when deferred the type includes undefined
 const onMemo4: Accessor<number> = onMemo3;
 
+//////////////////////////////////////////////////////////////////////////
+// createSelector ////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////////
+
+{
+  const selector = createSelector(() => 123);
+  const bool: boolean = selector(123);
+  // @ts-expect-error Argument of type 'string' is not assignable to parameter of type 'number'. ts(2345)
+  const bool2: boolean = selector("123");
+}
+{
+  const selector = createSelector(() => 123, undefined, { name: "test" });
+  const bool: boolean = selector(123);
+  // @ts-expect-error Argument of type 'string' is not assignable to parameter of type 'number'. ts(2345)
+  const bool2: boolean = selector("123");
+}
+{
+  const selector = createSelector<number | string>(() => 123);
+  const bool: boolean = selector(123);
+  const bool2: boolean = selector("123");
+  // @ts-expect-error Argument of type 'null' is not assignable to parameter of type 'string | number'. ts(2345)
+  const bool3: boolean = selector(null);
+}
+{
+  const selector = createSelector(
+    () => 123,
+    (key, source) => key === source
+  );
+  const bool: boolean = selector(123);
+  // @ts-expect-error Argument of type 'string' is not assignable to parameter of type 'number'. ts(2345)
+  const bool2: boolean = selector("123");
+}
+{
+  const selector = createSelector(
+    () => 123,
+    (key: string, source) => Number(key) === source
+  );
+  // @ts-expect-error Argument of type 'number' is not assignable to parameter of type 'string'. ts(2345)
+  const bool: boolean = selector(123);
+  const bool2: boolean = selector("123");
+}
+{
+  const selector = createSelector(
+    () => 123,
+    (key, source) => key === source,
+    { name: "test" }
+  );
+  const bool: boolean = selector(123);
+  // @ts-expect-error Argument of type 'string' is not assignable to parameter of type 'number'. ts(2345)
+  const bool2: boolean = selector("123");
+}
+
 //////////////////////////////////////////////////////////////////////////
 // variations of signal types ////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////////