core-app-api: avoid trying to load failed translations again

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/core-app-api/src/apis/implementations/TranslationApi/I18nextTranslationApi.test.ts

@@ -255,7 +255,7 @@ describe('I18nextTranslationApi', () => {
     expect(snapshot.t('bar')).toBe('Bär');
   });
 
-  it('should forward loading errors', async () => {
+  it('should forward loading errors and then ignore them', async () => {
     const languageApi = AppLanguageSelector.create();
     const translationApi = I18nextTranslationApi.create({
       languageApi,
@@ -270,6 +270,9 @@ describe('I18nextTranslationApi', () => {
     await expect(
       waitForNext(translationApi.translation$(plainRef), s => s.ready),
     ).rejects.toThrow('NOPE');
+
+    const snapshot = assertReady(translationApi.getTranslation(plainRef));
+    expect(snapshot.t('foo')).toBe('Foo');
   });
 
   it('should only call the loader once', async () => {

packages/core-app-api/src/apis/implementations/TranslationApi/I18nextTranslationApi.ts

@@ -121,10 +121,16 @@ class ResourceLoader {
       return;
     }
 
-    const load = loader().then(result => {
-      this.onLoad({ language, namespace, messages: result.messages });
-      this.#loaded.add(key);
-    });
+    const load = loader().then(
+      result => {
+        this.onLoad({ language, namespace, messages: result.messages });
+        this.#loaded.add(key);
+      },
+      error => {
+        this.#loaded.add(key); // Do not try to load failed resources again
+        throw error;
+      },
+    );
     this.#loading.set(key, load);
     await load;
   }