fix(store): disallow arrays in action creators (#2155)

Author: chrisguttandin

modules/store/spec/action_creator.spec.ts

@@ -77,11 +77,20 @@ describe('Action Creators', () => {
           const value = fooAction.bar;
       `).toFail(/'bar' does not exist on type/);
     });
+
     it('should not allow type property', () => {
       expectSnippet(`
             const foo = createAction('FOO', (type: string) => ({type}));
         `).toFail(
-        /Type '{ type: string; }' is not assignable to type '"type property is not allowed in action creators"/
+        /Type '{ type: string; }' is not assignable to type '"type property is not allowed in action creators"'/
+      );
+    });
+
+    it('should not allow ararys', () => {
+      expectSnippet(`
+          const foo = createAction('FOO', () => [ ]);
+        `).toFail(
+        /Type 'any\[]' is not assignable to type '"arrays are not allowed in action creators"'/
       );
     });
   });
@@ -150,12 +159,19 @@ describe('Action Creators', () => {
     });
 
     it('should not allow type property', () => {
-      const foo = createAction('FOO', props<{ type: number }>() as any);
       expectSnippet(`
           const foo = createAction('FOO', props<{ type: number }>());
         `).toFail(
         /Argument of type '"type property is not allowed in action creators"' is not assignable to parameter of type/
       );
     });
+
+    it('should not allow ararys', () => {
+      expectSnippet(`
+          const foo = createAction('FOO', props<[]>());
+        `).toFail(
+        /Argument of type '"arrays are not allowed in action creators"' is not assignable to parameter of type/
+      );
+    });
   });
 });

modules/store/src/action_creator.ts

@@ -4,7 +4,7 @@ import {
   TypedAction,
   FunctionWithParametersType,
   PropsReturnType,
-  DisallowTypeProperty,
+  DisallowArraysAndTypeProperty,
 } from './models';
 
 // Action creators taken from ts-action library and modified a bit to better
@@ -23,7 +23,7 @@ export function createAction<
   R extends object
 >(
   type: T,
-  creator: Creator<P, DisallowTypeProperty<R>>
+  creator: Creator<P, DisallowArraysAndTypeProperty<R>>
 ): FunctionWithParametersType<P, R & TypedAction<T>> & TypedAction<T>;
 /**
  * @description

modules/store/src/models.ts

@@ -53,9 +53,13 @@ export type SelectorWithProps<State, Props, Result> = (
   props: Props
 ) => Result;
 
-export type DisallowTypeProperty<T> = T extends { type: any }
-  ? TypePropertyIsNotAllowed
-  : T;
+export const arraysAreNotAllowedMsg =
+  'arrays are not allowed in action creators';
+type ArraysAreNotAllowed = typeof arraysAreNotAllowedMsg;
+
+export type DisallowArraysAndTypeProperty<T> = T extends any[]
+  ? ArraysAreNotAllowed
+  : T extends { type: any } ? TypePropertyIsNotAllowed : T;
 
 export const typePropertyIsNotAllowedMsg =
   'type property is not allowed in action creators';
@@ -67,13 +71,17 @@ type TypePropertyIsNotAllowed = typeof typePropertyIsNotAllowedMsg;
 export type Creator<
   P extends any[] = any[],
   R extends object = object
-> = R extends { type: any }
-  ? TypePropertyIsNotAllowed
-  : FunctionWithParametersType<P, R>;
-
-export type PropsReturnType<T extends object> = T extends { type: any }
-  ? TypePropertyIsNotAllowed
-  : { _as: 'props'; _p: T };
+> = R extends any[]
+  ? ArraysAreNotAllowed
+  : R extends { type: any }
+    ? TypePropertyIsNotAllowed
+    : FunctionWithParametersType<P, R>;
+
+export type PropsReturnType<T extends object> = T extends any[]
+  ? ArraysAreNotAllowed
+  : T extends { type: any }
+    ? TypePropertyIsNotAllowed
+    : { _as: 'props'; _p: T };
 
 /**
  * See `Creator`.