simplify signatures of ActionCreatorWithOptionalPayload and `Action…

…CreatorWithPayload`
reduxjs · Mar 11, 2020 · 982da2c · 982da2c
1 parent 36b25fc
commit 982da2c
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Showing 3 changed files with 10 additions and 24 deletions.
diff --git a/etc/redux-toolkit.api.md b/etc/redux-toolkit.api.md
@@ -28,8 +28,7 @@ export interface ActionCreatorWithNonInferrablePayload<T extends string = string
 
 // @public
 export interface ActionCreatorWithOptionalPayload<P, T extends string = string> extends BaseActionCreator<P, T> {
-    (payload?: undefined): PayloadAction<undefined, T>;
-    <PT extends Diff<P, undefined>>(payload?: PT): PayloadAction<PT, T>;
+    (payload?: P): PayloadAction<P, T>;
 }
 
 // @public
@@ -39,7 +38,6 @@ export interface ActionCreatorWithoutPayload<T extends string = string> extends
 
 // @public
 export interface ActionCreatorWithPayload<P, T extends string = string> extends BaseActionCreator<P, T> {
-    <PT extends P>(payload: PT): PayloadAction<PT, T>;
     (payload: P): PayloadAction<P, T>;
 }
 

diff --git a/src/createAction.ts b/src/createAction.ts
@@ -123,16 +123,12 @@ export interface ActionCreatorWithPreparedPayload<
  */
 export interface ActionCreatorWithOptionalPayload<P, T extends string = string>
   extends BaseActionCreator<P, T> {
-  /**
-   * Calling this {@link redux#ActionCreator} without arguments will
-   * return a {@link PayloadAction} of type `T` with a payload of `undefined`
-   */
-  (payload?: undefined): PayloadAction<undefined, T>
   /**
    * Calling this {@link redux#ActionCreator} with an argument will
-   * return a {@link PayloadAction} of type `T` with a payload of `P`
+   * return a {@link PayloadAction} of type `T` with a payload of `P`.
+   * Calling it without an argument will return a PayloadAction with a payload of `undefined`.
    */
-  <PT extends Diff<P, undefined>>(payload?: PT): PayloadAction<PT, T>
+  (payload?: P): PayloadAction<P, T>
 }
 
 /**
@@ -160,12 +156,6 @@ export interface ActionCreatorWithoutPayload<T extends string = string>
  */
 export interface ActionCreatorWithPayload<P, T extends string = string>
   extends BaseActionCreator<P, T> {
-  /**
-   * Calling this {@link redux#ActionCreator} with an argument will
-   * return a {@link PayloadAction} of type `T` with a payload of `P`
-   * If possible, `P` will be narrowed down to the exact type of the payload argument.
-   */
-  <PT extends P>(payload: PT): PayloadAction<PT, T>
   /**
    * Calling this {@link redux#ActionCreator} with an argument will
    * return a {@link PayloadAction} of type `T` with a payload of `P`
@@ -333,8 +323,6 @@ export function getType<T extends string>(
 
 // helper types for more readable typings
 
-type Diff<T, U> = T extends U ? never : T
-
 type IfPrepareActionMethodProvided<
   PA extends PrepareAction<any> | void,
   True,

diff --git a/type-tests/files/createAction.typetest.ts b/type-tests/files/createAction.typetest.ts
@@ -73,9 +73,9 @@ function expectType<T>(p: T): T {
     { type: 'action' }
   ) as PayloadActionCreator<number | undefined>
 
-  expectType<PayloadAction<number>>(actionCreator(1))
-  expectType<PayloadAction<undefined>>(actionCreator())
-  expectType<PayloadAction<undefined>>(actionCreator(undefined))
+  expectType<PayloadAction<number | undefined>>(actionCreator(1))
+  expectType<PayloadAction<number | undefined>>(actionCreator())
+  expectType<PayloadAction<number | undefined>>(actionCreator(undefined))
 
   // typings:expect-error
   expectType<PayloadAction<number>>(actionCreator())
@@ -104,9 +104,9 @@ function expectType<T>(p: T): T {
     { type: 'action' }
   ) as PayloadActionCreator<number>
 
-  const actionCreator2: ActionCreator<
-    PayloadAction<number>
-  > = payloadActionCreator2
+  const actionCreator2: ActionCreator<PayloadAction<
+    number
+  >> = payloadActionCreator2
 }
 
 /* createAction() */