fix(middleware): devtools type error #2700 (#2875)

* fix: add an inferred generic U to CreateStoreImpl

* fix: add inferred generic U variables to both Devtools and DevtoolsImpl

* test: add tests for issue #2700

* revert impl types

* code styling

---------

Co-authored-by: daishi <daishi@axlight.com>

src/middleware/devtools.ts

@@ -79,8 +79,9 @@ type Devtools = <
   T,
   Mps extends [StoreMutatorIdentifier, unknown][] = [],
   Mcs extends [StoreMutatorIdentifier, unknown][] = [],
+  U = T,
 >(
-  initializer: StateCreator<T, [...Mps, ['zustand/devtools', never]], Mcs>,
+  initializer: StateCreator<T, [...Mps, ['zustand/devtools', never]], Mcs, U>,
   devtoolsOptions?: DevtoolsOptions,
 ) => StateCreator<T, Mps, [['zustand/devtools', never], ...Mcs]>
 

tests/middlewareTypes.test.tsx

@@ -177,6 +177,24 @@ describe('counter state spec (single middleware)', () => {
     expect(testSubtyping).toBeDefined()
   })
 
+  it('devtools #2700', () => {
+    type TableStore = {
+      table: string
+    }
+    const useStoreA = create<TableStore | null>()(
+      devtools((_set) => null, { name: 'table-storage' }),
+    )
+    expect(useStoreA).toBeDefined()
+    const useStoreB = create<TableStore | null>()(
+      devtools(() => null, { name: 'table-storage' }),
+    )
+    expect(useStoreB).toBeDefined()
+    const useStoreC = create<TableStore | null>()((_set) => null)
+    expect(useStoreC).toBeDefined()
+    const useStoreD = create<TableStore | null>()(() => null)
+    expect(useStoreD).toBeDefined()
+  })
+
   it('subscribeWithSelector', () => {
     const useBoundStore = create<CounterState>()(
       subscribeWithSelector((set, get) => ({