increase subselector number

reduxjs · Oct 26, 2021 · 4ead716 · 4ead716
1 parent 508e0dd
commit 4ead716
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Showing 2 changed files with 100 additions and 16 deletions.
diff --git a/src/types.ts b/src/types.ts
@@ -34,18 +34,22 @@ export type OutputParametricSelector<State, Props, Result, Combiner> =
 export type SelectorArray = ReadonlyArray<Selector>
 
 type GetStateFromSelector<S> = S extends Selector<infer State> ? State : never
-type GetStateFromSelectors<S extends SelectorArray> = S extends [
-  infer Current,
-  ...infer Other
-]
-  ? Current extends Selector
+export type GetStateFromSelectors<S extends SelectorArray> =
+  // handle two elements at once so this type works for up to 30 selectors
+  S extends [infer C1, infer C2, ...infer Other]
+    ? Other extends SelectorArray
+      ?
+          | GetStateFromSelector<C1>
+          | GetStateFromSelector<C2>
+          | GetStateFromSelectors<Other>
+      : GetStateFromSelector<C1> | GetStateFromSelector<C2>
+    : S extends [infer Current, ...infer Other]
     ? Other extends SelectorArray
       ? GetStateFromSelector<Current> | GetStateFromSelectors<Other>
       : GetStateFromSelector<Current>
+    : S extends (infer Elem)[]
+    ? GetStateFromSelector<Elem>
     : never
-  : S extends (infer Elem)[]
-  ? GetStateFromSelector<Elem>
-  : never
 
 export type GetParamsFromSelector<S> = S extends Selector<any, any, infer P>
   ? P extends []
@@ -62,17 +66,27 @@ export type GetParamsFromSelectors<S, Found = never> = S extends SelectorArray
     : S
   : Found
 
+type SelectorReturnType<S> = S extends Selector ? ReturnType<S> : never
+
 export type SelectorResultArray<
   Selectors extends SelectorArray,
   Rest extends SelectorArray = Selectors
-> = Rest extends [infer S, ...infer Remaining]
-  ? S extends Selector
+> =
+  // handle two elements at once so this type works for up to 29 selectors, not only up to 15
+  Rest extends [infer S1, infer S2, ...infer Remaining]
+    ? Remaining extends SelectorArray
+      ? [
+          SelectorReturnType<S1>,
+          SelectorReturnType<S2>,
+          ...SelectorResultArray<Selectors, Remaining>
+        ]
+      : [SelectorReturnType<S1>, SelectorReturnType<S2>]
+    : Rest extends [infer S, ...infer Remaining]
     ? Remaining extends SelectorArray
-      ? [ReturnType<S>, ...SelectorResultArray<Selectors, Remaining>]
-      : [ReturnType<S>]
+      ? [SelectorReturnType<S>, ...SelectorResultArray<Selectors, Remaining>]
+      : [SelectorReturnType<S>]
+    : Rest extends ((...args: any) => infer S)[]
+    ? S[]
     : []
-  : Rest extends ((...args: any) => infer S)[]
-  ? S[]
-  : []
 
 export type EqualityFn = (a: any, b: any) => boolean
diff --git a/typescript_test/test.ts b/typescript_test/test.ts
@@ -5,7 +5,9 @@ import {
   createSelectorCreator,
   createStructuredSelector,
   ParametricSelector,
-  OutputSelector
+  OutputSelector,
+  SelectorResultArray,
+  GetParamsFromSelectors
 } from '../src/index'
 
 import microMemoize from 'micro-memoize'
@@ -717,6 +719,7 @@ function multiArgMemoize<F extends (...args: any[]) => any>(
 
 // #384: check for defaultMemoize
 import { isEqual, groupBy } from 'lodash'
+import { GetStateFromSelectors } from '../src/types'
 
 {
   interface Transaction {
@@ -990,3 +993,70 @@ function createSelectorConfigOptions() {
     }
   )
 }
+
+const withLotsOfInputSelectors = createSelector(
+  (_state: any) => 1,
+  (_state: any) => 2,
+  (_state: any) => 3,
+  (_state: any) => 4,
+  (_state: any) => 5,
+  (_state: any) => 6,
+  (_state: any) => 7,
+  (_state: any) => 8,
+  (_state: any) => 9,
+  (_state: any) => 10,
+  (_state: any) => 11,
+  (_state: any) => 12,
+  (_state: any) => 13,
+  (_state: any) => 14,
+  (_state: any) => 15,
+  (_state: any) => 16,
+  (_state: any) => 17,
+  (_state: any) => 18,
+  (_state: any) => 19,
+  (_state: any) => 20,
+  (_state: any) => 21,
+  (_state: any) => 22,
+  (_state: any) => 23,
+  (_state: any) => 24,
+  (_state: any) => 25,
+  (_state: any) => 26,
+  (_state: any) => 27,
+  (_state: any) => 28,
+  (...args) => args.length
+)
+
+type SelectorArray29 = [
+  (_state: any) => 1,
+  (_state: any) => 2,
+  (_state: any) => 3,
+  (_state: any) => 4,
+  (_state: any) => 5,
+  (_state: any) => 6,
+  (_state: any) => 7,
+  (_state: any) => 8,
+  (_state: any) => 9,
+  (_state: any) => 10,
+  (_state: any) => 11,
+  (_state: any) => 12,
+  (_state: any) => 13,
+  (_state: any) => 14,
+  (_state: any) => 15,
+  (_state: any) => 16,
+  (_state: any) => 17,
+  (_state: any) => 18,
+  (_state: any) => 19,
+  (_state: any) => 20,
+  (_state: any) => 21,
+  (_state: any) => 22,
+  (_state: any) => 23,
+  (_state: any) => 24,
+  (_state: any) => 25,
+  (_state: any) => 26,
+  (_state: any) => 27,
+  (_state: any) => 28,
+  (_state: any) => 29
+]
+
+type Results = SelectorResultArray<SelectorArray29>
+type State = GetStateFromSelectors<SelectorArray29>