Improve selector types

solidjs · Jun 4, 2023 · a7270bc · a7270bc
1 parent 0b80eb7
commit a7270bc
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Showing 2 changed files with 18 additions and 18 deletions.
diff --git a/packages/solid/src/reactive/signal.ts b/packages/solid/src/reactive/signal.ts
@@ -784,18 +784,8 @@ export type EqualityCheckerFunction<T, U> = (a: U, b: T) => boolean;
  *
  * @description https://www.solidjs.com/docs/latest/api#createselector
  */
-// default equality checke
-export function createSelector<T, U /* U left for backwards compatibility */>(
-  source: Accessor<T>
-): (key: T) => boolean;
-// custom equality checker
-export function createSelector<T, U /* U left for backwards compatibility */>(
-  source: Accessor<T>,
-  fn: EqualityCheckerFunction<T, T>,
-  options?: BaseOptions
-): (key: T) => boolean;
-// custom equality checker and key type
-export function createSelector<T, U>(
+export function createSelector<T, U = T>(source: Accessor<T>): (key: U) => boolean;
+export function createSelector<T, U = T>(
   source: Accessor<T>,
   fn: EqualityCheckerFunction<T, U>,
   options?: BaseOptions

diff --git a/packages/solid/test/signals.type-tests.ts b/packages/solid/test/signals.type-tests.ts
@@ -716,22 +716,32 @@ const onMemo4: Accessor<number> = onMemo3;
 //////////////////////////////////////////////////////////////////////////
 
 {
-  const source = (): number => 123;
-  const selector = createSelector(source);
+  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 source = (): number => 123;
-  const selector = createSelector(source, (key, source) => key === source);
+  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 source = (): number => 123;
-  const selector = createSelector(source, (key: string, source) => Number(key) === source);
+  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");