Updated createReducer api with new method handleType

piotrwitek · Jun 24, 2019 · d3850a0 · d3850a0
1 parent dfe3240
commit d3850a0
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Showing 4 changed files with 67 additions and 38 deletions.
diff --git a/benchmarks/150-actions.ts b/benchmarks/150-actions.ts
@@ -313,4 +313,5 @@ export const reducer2 = createReducer<number, RootAction>(0)
   .handleAction(actions.c22, state => state)
   .handleAction(actions.c23, state => state)
   .handleAction(actions.c24, state => state)
-  .handleAction(actions.c25, state => state);
+  .handleAction(actions.c25, state => state)
+  .handleType(['c26', 'c27', 'c28', 'c29', 'c30'], (s, a) => s);
diff --git a/src/create-reducer.spec.ts b/src/create-reducer.spec.ts
@@ -186,7 +186,7 @@ const initialState = 0;
 {
   const reducerTest = createReducer(initialState);
 
-  const counterReducer1 = reducerTest.handleAction(
+  const counterReducer1 = reducerTest.handleType(
     ['ADD', 'INCREMENT'],
     (state, action) => state + (action.type === 'ADD' ? action.payload : 1)
   );
@@ -198,16 +198,16 @@ const initialState = 0;
   Object.keys({ ...reducerTest.handlers }); // => []
 
   const counterReducer2 = reducerTest
-    .handleAction(['ADD'], (state, action) => state + action.payload)
-    .handleAction(['INCREMENT'], (state, _) => state + 1);
+    .handleType(['ADD'], (state, action) => state + action.payload)
+    .handleType(['INCREMENT'], (state, _) => state + 1);
   // @dts-jest:pass:snap
   counterReducer2.handlers;
   // @dts-jest:pass
   Object.keys({ ...counterReducer2.handlers }); // => ["ADD", "INCREMENT"]
   // @dts-jest:pass
   Object.keys({ ...reducerTest.handlers }); // => []
 
-  const counterReducer3 = reducerTest.handleAction(
+  const counterReducer3 = reducerTest.handleType(
     'ADD',
     (state, action) => state + action.payload
   );
@@ -218,7 +218,7 @@ const initialState = 0;
   // @dts-jest:pass
   Object.keys({ ...reducerTest.handlers }); // => []
 
-  const counterReducer4 = reducerTest.handleAction(
+  const counterReducer4 = reducerTest.handleType(
     'INCREMENT',
     (state, _) => state + 1
   );

diff --git a/src/create-reducer.ts b/src/create-reducer.ts
@@ -4,28 +4,20 @@ import {
   checkValidActionType,
   throwInvalidActionTypeOrActionCreator,
 } from './utils/validation';
-import { Reducer, Action, Types } from './type-helpers';
+import { Reducer, Action, Types, ActionCreator } from './type-helpers';
 
-type CreateReducerChainApi<
+type HandleActionChainApi<
   TState,
-  TPrevNotHandledAction extends Action,
+  TInputAction extends Action,
   TRootAction extends Action
 > = <
-  TType extends TPrevNotHandledAction['type'],
-  TCreator extends (...args: any[]) => TPrevNotHandledAction,
-  TNextNotHandledAction extends Exclude<
-    TPrevNotHandledAction,
-    Action<TType> & ReturnType<TCreator>
-  >,
-  TAction extends TPrevNotHandledAction extends Action<TType>
-    ? TPrevNotHandledAction extends ReturnType<TCreator>
-      ? TPrevNotHandledAction
-      : never
-    : never
+  TActionCreator extends (...args: any[]) => TInputAction,
+  THandledAction extends ReturnType<TActionCreator>,
+  TOutputAction extends Exclude<TInputAction, THandledAction>
 >(
-  singleOrMultipleCreatorsAndTypes: TType | TType[] | TCreator | TCreator[],
-  reducer: (state: TState, action: TAction) => TState
-) => [TNextNotHandledAction] extends [never]
+  singleOrMultipleCreatorsAndTypes: TActionCreator | TActionCreator[],
+  reducer: (state: TState, action: THandledAction) => TState
+) => [TOutputAction] extends [never]
   ? Reducer<TState, TRootAction> & {
       handlers: Record<
         TRootAction['type'],
@@ -34,14 +26,38 @@ type CreateReducerChainApi<
     }
   : Reducer<TState, TRootAction> & {
       handlers: Record<
-        Exclude<TRootAction, TNextNotHandledAction>['type'],
+        Exclude<TRootAction, TOutputAction>['type'],
         (state: TState, action: TRootAction) => TState
       >;
-      handleAction: CreateReducerChainApi<
-        TState,
-        TNextNotHandledAction,
-        TRootAction
+      handleAction: HandleActionChainApi<TState, TOutputAction, TRootAction>;
+      handleType: HandleTypeChainApi<TState, TOutputAction, TRootAction>;
+    };
+
+type HandleTypeChainApi<
+  TState,
+  TInputAction extends Action,
+  TRootAction extends Action
+> = <
+  TType extends TInputAction['type'],
+  THandledAction extends Extract<TInputAction, Action<TType>>,
+  TOutputAction extends Exclude<TInputAction, THandledAction>
+>(
+  singleOrMultipleCreatorsAndTypes: TType | TType[],
+  reducer: (state: TState, action: THandledAction) => TState
+) => [TOutputAction] extends [never]
+  ? Reducer<TState, TRootAction> & {
+      handlers: Record<
+        TRootAction['type'],
+        (state: TState, action: TRootAction) => TState
+      >;
+    }
+  : Reducer<TState, TRootAction> & {
+      handlers: Record<
+        Exclude<TRootAction, TOutputAction>['type'],
+        (state: TState, action: TRootAction) => TState
       >;
+      handleAction: HandleActionChainApi<TState, TOutputAction, TRootAction>;
+      handleType: HandleTypeChainApi<TState, TOutputAction, TRootAction>;
     };
 
 type GetAction<
@@ -83,31 +99,43 @@ export function createReducer<TState, TRootAction extends Action = RootAction>(
     }
   };
 
-  const handleAction = ((singleOrMultipleCreatorsAndTypes, reducer) => {
+  const reducerHandler = ((singleOrMultipleCreatorsAndTypes, reducer) => {
     const creatorsAndTypes = Array.isArray(singleOrMultipleCreatorsAndTypes)
       ? singleOrMultipleCreatorsAndTypes
       : [singleOrMultipleCreatorsAndTypes];
 
     const newHandlers: typeof handlers = {};
     creatorsAndTypes
-      .map(acOrType =>
-        checkValidActionCreator(acOrType)
-          ? getType(acOrType)
-          : checkValidActionType(acOrType)
-          ? acOrType
-          : throwInvalidActionTypeOrActionCreator()
+      .map(
+        (acOrType: TRootAction['type'] | ((...args: any[]) => TRootAction)) =>
+          checkValidActionCreator(acOrType)
+            ? getType(acOrType)
+            : checkValidActionType(acOrType)
+            ? acOrType
+            : throwInvalidActionTypeOrActionCreator()
       )
       .forEach(type => (newHandlers[type] = reducer));
 
     return createReducer<TState, TRootAction>(initialState, {
       ...handlers,
       ...newHandlers,
     });
-  }) as CreateReducerChainApi<TState, TRootAction, TRootAction>;
+  }) as
+    | HandleActionChainApi<TState, TRootAction, TRootAction>
+    | HandleTypeChainApi<TState, TRootAction, TRootAction>;
 
   const chainApi = Object.assign(rootReducer, {
     handlers: { ...handlers },
-    handleAction,
+    handleAction: reducerHandler as HandleActionChainApi<
+      TState,
+      TRootAction,
+      TRootAction
+    >,
+    handleType: reducerHandler as HandleTypeChainApi<
+      TState,
+      TRootAction,
+      TRootAction
+    >,
   } as const);
 
   return chainApi;

diff --git a/src/type-helpers.ts b/src/type-helpers.ts
@@ -29,7 +29,7 @@ export type Action<TType extends TypeConstant = TypeConstant> = {
 /**
  * @desc Type representing Generic ActionCreator
  */
-export type ActionCreator<TType extends TypeConstant> = (
+export type ActionCreator<TType extends TypeConstant = TypeConstant> = (
   ...args: any[]
 ) => Action<TType>;