fix(types): infer type from target firestore

src/firestore/bind.ts

@@ -27,7 +27,8 @@ import { onSnapshot } from 'firebase/firestore'
 /**
  * Options when binding a Firestore document or collection.
  */
-export interface FirestoreRefOptions extends _DataSourceOptions {
+export interface FirestoreRefOptions<TData = unknown>
+  extends _DataSourceOptions<TData> {
   /**
    * The maximum depth to bind nested refs. A nested ref that isn't bound will stay as the ref path while a bound ref
    * will contain the same data as if the ref was bound directly.

src/firestore/index.ts

@@ -59,7 +59,8 @@ export function useCollection<T>(
   }) as _RefFirestore<VueFirestoreQueryData<T>>
 }
 
-export interface UseDocumentOptions extends _UseFirestoreRefOptions {}
+export interface UseDocumentOptions<TData = unknown>
+  extends _UseFirestoreRefOptions<TData> {}
 
 /**
  * Creates a reactive document from a document ref from Firestore. Automatically extracts the type of the converter or
@@ -73,7 +74,7 @@ export function useDocument<
   R extends DocumentReference<unknown>
 >(
   documentRef: MaybeRefOrGetter<_Nullable<R>>,
-  options?: UseDocumentOptions
+  options?: UseDocumentOptions<_InferReferenceType<R>>
 ): _RefFirestore<_InferReferenceType<R> | undefined> // this one can't be null or should be specified in the converter
 
 /**
@@ -86,12 +87,12 @@ export function useDocument<
  */
 export function useDocument<T>(
   documentRef: MaybeRefOrGetter<_Nullable<DocumentReference>>,
-  options?: UseDocumentOptions
+  options?: UseDocumentOptions<T>
 ): _RefFirestore<VueFirestoreDocumentData<T> | undefined>
 
 export function useDocument<T>(
   documentRef: MaybeRefOrGetter<_Nullable<DocumentReference<unknown>>>,
-  options?: UseDocumentOptions
+  options?: UseDocumentOptions<T>
 ): _RefFirestore<VueFirestoreDocumentData<T> | undefined> {
   // no unwrapRef to have a simpler type
   return _useFirestoreRef(documentRef, options) as _RefFirestore<

src/firestore/useFirestoreRef.ts

@@ -42,7 +42,8 @@ import {
   _FirestoreRefOptionsWithDefaults,
 } from './bind'
 
-export interface _UseFirestoreRefOptions extends FirestoreRefOptions {
+export interface _UseFirestoreRefOptions<TData = unknown>
+  extends FirestoreRefOptions<TData> {
   /**
    * @deprecated: use `.withConverter()` instead
    */

src/shared.ts

@@ -30,6 +30,13 @@ export interface OperationsType {
  */
 export type ResetOption = boolean | (() => unknown)
 
+/**
+ * Flattens out a type.
+ *
+ * @internal
+ */
+export type _Simplify<T> = { [KeyType in keyof T]: T[KeyType] } & {}
+
 /**
  * Return type of `$databaseBind()` and `$firestoreBind()`
  */
@@ -228,11 +235,11 @@ export interface _RefWithState<T, E = Error> extends Ref<T> {
  *
  * @internal
  */
-export interface _DataSourceOptions {
+export interface _DataSourceOptions<DataT = unknown> {
   /**
    * Use the `target` ref instead of creating one.
    */
-  target?: Ref<unknown>
+  target?: Ref<DataT>
 
   /**
    * Optional key to handle SSR hydration. **Necessary for Queries** or when the same source is used in multiple places

tests/firestore/document.spec.ts

@@ -1,5 +1,5 @@
 import { mount } from '@vue/test-utils'
-import { beforeEach, describe, expect, it } from 'vitest'
+import { beforeEach, describe, expect, expectTypeOf, it } from 'vitest'
 import {
   addDoc,
   doc as originalDoc,
@@ -46,7 +46,7 @@ describe(
       options,
       ref = doc(),
     }: {
-      options?: UseDocumentOptions
+      options?: UseDocumentOptions<T>
       ref?: MaybeRefOrGetter<DocumentReference<T>>
     } = {}) {
       let data!: _RefFirestore<VueFirestoreDocumentData<T>>
@@ -341,18 +341,28 @@ describe(
         finished: boolean
       }
 
-      expectType<Ref<DocumentData | null | undefined>>(useDocument(itemRef))
-      // @ts-expect-error
-      expectType<Ref<number | null>>(useDocument(itemRef))
+      expectTypeOf(useDocument(itemRef).value).toEqualTypeOf<
+        DocumentData | undefined
+      >()
 
       // Adds the id
+
       // FIXME: this one is any but the test passes
-      expectType<string>(useDocument(doc(db, 'todos', '1')).value?.id)
-      expectType<string>(useDocument<TodoI>(doc(db, 'todos', '1')).value!.id)
-      expectType<_Nullable<TodoI>>(
+      expectTypeOf(
+        useDocument(doc(db, 'todos', '1')).value!.id
+        // @ts-expect-error:
+      ).toEqualTypeOf<string>()
+
+      expectTypeOf(
         useDocument<TodoI>(doc(db, 'todos', '1')).value
-      )
-      expectType<string>(useDocument<unknown>(doc(db, 'todos', '1')).value!.id)
+      ).toMatchTypeOf<_Nullable<TodoI>>()
+      expectTypeOf(
+        useDocument<unknown>(doc(db, 'todos', '1')).value!.id
+      ).toBeString()
+      expectTypeOf(
+        useDocument<TodoI>(doc(db, 'todos', '1')).value!.id
+      ).toBeString()
+
       useDocument(
         doc(db, 'todos').withConverter<TodoI, DocumentData>({
           fromFirestore: (snapshot) => {
@@ -364,7 +374,10 @@ describe(
         // @ts-expect-error: no id with custom converter
       ).value?.id
 
-      expectType<Ref<number | null | undefined>>(useDocument<number>(itemRef))
+      expectTypeOf(useDocument<number>(itemRef)).toMatchTypeOf<
+        Ref<_Nullable<number | null | undefined>>
+      >()
+
       expectType<Ref<number | null | undefined>>(
         useDocument<number>(itemRef).data
       )
@@ -375,12 +388,15 @@ describe(
         toFirestore: (data) => ({ n: data }),
         fromFirestore: (snap, options) => snap.data(options).n as number,
       })
-      expectType<Ref<number | number | undefined>>(
-        useDocument(refWithConverter)
-      )
-      expectType<Ref<number | number | undefined>>(
-        useDocument(refWithConverter).data
-      )
+      expectTypeOf(useDocument(refWithConverter)).toMatchTypeOf<
+        Ref<number | undefined>
+      >()
+      expectTypeOf(useDocument(refWithConverter).value).toEqualTypeOf<
+        number | undefined
+      >()
+      expectTypeOf(useDocument(refWithConverter).data).toEqualTypeOf<
+        Ref<number | undefined>
+      >()
       // should not be null
       useDocument(refWithConverter).value?.toFixed(14)
       // @ts-expect-error: string is not assignable to number
@@ -389,11 +405,13 @@ describe(
       useDocument(refWithConverter).value.id
 
       // destructuring
-      expectType<Ref<DocumentData | null | undefined>>(
-        useDocument(itemRef).data
-      )
-      expectType<Ref<FirestoreError | undefined>>(useDocument(itemRef).error)
-      expectType<Ref<boolean>>(useDocument(itemRef).pending)
+      expectTypeOf(useDocument(itemRef).data).toEqualTypeOf<
+        Ref<DocumentData | undefined>
+      >()
+      expectTypeOf(useDocument(itemRef).error).toEqualTypeOf<
+        Ref<FirestoreError | undefined>
+      >()
+      expectTypeOf(useDocument(itemRef).pending).toEqualTypeOf<Ref<boolean>>()
     })
   },
   { retry: 3 }