fix: tighten ReactFireOptions generic types, remove T | any widening

.npmignore

@@ -0,0 +1 @@
+src/*.type-test.ts

src/firestore.tsx

@@ -63,7 +63,7 @@ export function useFirestoreDocData<T = unknown>(ref: DocumentReference<T>, opti
   const idField = options ? checkIdField(options) : undefined;
 
   const observableId = `firestore:docData:${ref.firestore.app.name}:${ref.path}:idField=${JSON.stringify(idField)}`;
-  const observable = docData(ref, { idField });
+  const observable = docData(ref, { idField: idField as keyof T });
 
   return useObservable(observableId, observable, options) as ObservableStatus<T>;
 }
@@ -75,7 +75,7 @@ export function useFirestoreDocDataOnce<T = unknown>(ref: DocumentReference<T>,
   const idField = options ? checkIdField(options) : undefined;
 
   const observableId = `firestore:docDataOnce:${ref.firestore.app.name}:${ref.path}:idField=${JSON.stringify(idField)}`;
-  const observable$ = docData(ref, { idField }).pipe(first());
+  const observable$ = docData(ref, { idField: idField as keyof T }).pipe(first());
 
   return useObservable(observableId, observable$, options) as ObservableStatus<T>;
 }
@@ -96,7 +96,7 @@ export function useFirestoreCollection<T = DocumentData>(query: FirestoreQuery<T
 export function useFirestoreCollectionData<T = DocumentData>(query: FirestoreQuery<T>, options?: ReactFireOptions<T[]>): ObservableStatus<T[]> {
   const idField = options ? checkIdField(options) : undefined;
   const observableId = `firestore:collectionData:${getUniqueIdForFirestoreQuery(query)}:idField=${JSON.stringify(idField)}`;
-  const observable$ = collectionData(query, { idField });
+  const observable$ = collectionData(query, { idField: idField as (string & keyof T) });
 
   return useObservable(observableId, observable$, options);
 }

src/index.ts

@@ -23,14 +23,16 @@ export class ReactFireError extends Error {
 
 export interface ReactFireOptions<T = unknown> {
   idField?: string;
-  initialData?: T | any;
+  initialData?: T;
   /**
    * @deprecated use initialData instead
    */
-  startWithValue?: T | any;
+  startWithValue?: T;
   suspense?: boolean;
 }
 
+// Deprecated: unused internally as of the ReactFireOptions generic tightening.
+// Kept as exports to avoid a breaking removal; slated for removal in v5.
 export function checkOptions(options: ReactFireOptions, field: string) {
   // make sure the field passed in is a valid key of ReactFire Options
   if (field === 'idField' || field === 'initialData' || field === 'suspense') {
@@ -44,8 +46,8 @@ export function checkinitialData(options: ReactFireOptions) {
   return checkOptions(options, 'initialData');
 }
 
-export function checkIdField(options: ReactFireOptions) {
-  return checkOptions(options, 'idField');
+export function checkIdField(options: ReactFireOptions): string | undefined {
+  return options?.idField;
 }
 
 export * from './auth';

src/reactfire-options.type-test.ts

@@ -0,0 +1,18 @@
+/**
+ * Type-level regression tests for ReactFireOptions<T> generic constraints.
+ * Checked by `tsc --noEmit` in CI. No runtime behavior — not bundled.
+ */
+import type { ReactFireOptions } from './index';
+
+// ---- initialData must match T ----
+
+void ((): ReactFireOptions<string> => ({ initialData: 'hello' }))();
+void ((): ReactFireOptions<number> => ({ initialData: 42 }))();
+
+// @ts-expect-error initialData must be T, not a different type
+const _wrongInitialData: ReactFireOptions<string> = { initialData: 123 };
+void _wrongInitialData;
+
+// @ts-expect-error startWithValue must be T, not a different type
+const _wrongStartWithValue: ReactFireOptions<string> = { startWithValue: 123 };
+void _wrongStartWithValue;