Normalize preferred locale (#528)

Author: marcospassos

package-lock.json

@@ -42,7 +42,7 @@
     "react-dom": "^16.8.0  || ^17.0.0 || ^18.0.0 || ^19.0.0"
   },
   "dependencies": {
-    "@croct/plug": "^0.17.0",
+    "@croct/plug": "^0.17.1",
     "@croct/sdk": "^0.18.0"
   },
   "devDependencies": {

package.json

@@ -64,4 +64,21 @@ describe('useContent (SSR)', () => {
 
         expect(result.current).toBe(initial);
     });
+
+    it('should normalize an empty preferred locale to undefined', () => {
+        const slotId = 'slot-id';
+        const preferredLocale = '';
+
+        jest.mocked(getSlotContent).mockReturnValue({
+            foo: 'bar',
+        });
+
+        renderHook(
+            () => useContent(slotId, {
+                preferredLocale: preferredLocale,
+            }),
+        );
+
+        expect(getSlotContent).toHaveBeenCalledWith(slotId, undefined);
+    });
 });

src/hooks/useContent.ssr.test.ts

@@ -290,4 +290,27 @@ describe('useContent (CSR)', () => {
             preferredLocale: preferredLocale,
         });
     });
+
+    it('should normalize an empty preferred locale to undefined', () => {
+        const fetch: Plug['fetch'] = jest.fn().mockResolvedValue({
+            content: {},
+        });
+
+        jest.mocked(useCroct).mockReturnValue({fetch: fetch} as Plug);
+
+        renderHook(
+            () => useContent('slot-id', {
+                preferredLocale: '',
+            }),
+        );
+
+        jest.mocked(useLoader)
+            .mock
+            .calls[0][0]
+            .loader();
+
+        expect(fetch).toHaveBeenCalledWith('slot-id', {
+            preferredLocale: undefined,
+        });
+    });
 });

src/hooks/useContent.test.ts

@@ -28,7 +28,7 @@ function useCsrContent<I, F>(
         ...fetchOptions
     } = options;
 
-    const {preferredLocale} = fetchOptions;
+    const preferredLocale = normalizePreferredLocale(fetchOptions.preferredLocale);
     const defaultContent = useMemo(
         () => getSlotContent(id, preferredLocale) as SlotContent|null ?? undefined,
         [id, preferredLocale],
@@ -47,7 +47,11 @@ function useCsrContent<I, F>(
             + `:${preferredLocale ?? ''}`
             + `:${JSON.stringify(fetchOptions.attributes ?? {})}`,
         ),
-        loader: () => croct.fetch(id, {...fetchOptions, fallback: fallback}).then(({content}) => content),
+        loader: () => croct.fetch(id, {
+            ...fetchOptions,
+            preferredLocale: preferredLocale,
+            fallback: fallback,
+        }).then(({content}) => content),
         initial: initial,
         expiration: expiration,
     });
@@ -75,7 +79,7 @@ function useSsrContent<I, F>(
     {initial, preferredLocale}: UseContentOptions<I, F> = {},
 ): SlotContent | I | F {
     const resolvedInitialContent = initial === undefined
-        ? getSlotContent(slotId, preferredLocale) as I|null ?? undefined
+        ? getSlotContent(slotId, normalizePreferredLocale(preferredLocale)) as I|null ?? undefined
         : initial;
 
     if (resolvedInitialContent === undefined) {
@@ -88,6 +92,10 @@ function useSsrContent<I, F>(
     return resolvedInitialContent;
 }
 
+function normalizePreferredLocale(preferredLocale: string|undefined): string|undefined {
+    return preferredLocale !== undefined && preferredLocale !== '' ? preferredLocale : undefined;
+}
+
 type UseContentHook = {
     <P extends JsonObject, I = P, F = P>(
         id: keyof VersionedSlotMap extends never ? string : never,