feat: remove remnant x-axios-headers from server response

src/interceptors/response.ts

@@ -54,7 +54,7 @@ export function defaultResponseInterceptor(
       if (__ACI_DEV__) {
         axios.debug?.({
           id,
-          msg: 'Response with config.cache === false',
+          msg: 'Response with config.cache falsy',
           data: response
         });
       }
@@ -82,7 +82,7 @@ export function defaultResponseInterceptor(
 
     // Config told that this response should be cached.
     if (
-      // For 'loading' values (post stale), this check was already run in the past.
+      // For 'loading' values (previous: stale), this check already ran in the past.
       !cache.data &&
       !(await testCachePredicate(response, cacheConfig.cachePredicate))
     ) {
@@ -98,13 +98,11 @@ export function defaultResponseInterceptor(
       return response;
     }
 
-    // avoid remnant headers from remote server to break implementation
-    for (const header in Header) {
-      if (!header.startsWith('XAxiosCache')) {
-        continue;
+    // Avoid remnant headers from remote server to break implementation
+    for (const header of Object.keys(response.headers)) {
+      if (header.startsWith('x-axios-cache')) {
+        delete response.headers[header];
       }
-
-      delete response.headers[header];
     }
 
     if (cacheConfig.etag && cacheConfig.etag !== true) {

src/util/update-cache.ts

@@ -8,10 +8,7 @@ export async function updateCache<T, D>(
   data: CacheAxiosResponse<T, D>,
   entries: Record<string, CacheUpdater<T, D>>
 ): Promise<void> {
-  for (const cacheKey in entries) {
-    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-    const updater = entries[cacheKey]!;
-
+  for (const [cacheKey, updater] of Object.entries(entries)) {
     if (updater === 'delete') {
       await storage.remove(cacheKey, data.config);
       continue;

test/interceptors/response.test.ts

@@ -158,4 +158,23 @@ describe('test request interceptor', () => {
     expect(id).toBeDefined();
     expect(typeof id).toBe('string');
   });
+
+  it('It expects that any X-axios-cache gets removed', async () => {
+    const headerValue = '23asdf8ghd';
+
+    const axios = mockAxios(
+      {},
+      {
+        [Header.XAxiosCacheEtag]: headerValue,
+        [Header.XAxiosCacheLastModified]: headerValue,
+        [Header.XAxiosCacheStaleIfError]: headerValue
+      }
+    );
+
+    const { headers } = await axios.get('url');
+
+    expect(headers[Header.XAxiosCacheEtag]).not.toBe(headerValue);
+    expect(headers[Header.XAxiosCacheLastModified]).not.toBe(headerValue);
+    expect(headers[Header.XAxiosCacheStaleIfError]).not.toBe(headerValue);
+  });
 });

test/interceptors/stale-if-error.test.ts

@@ -48,13 +48,16 @@ describe('Last-Modified handling', () => {
   });
 
   it('expects that XAxiosCacheStaleIfError is defined', async () => {
-    const axios = mockAxios();
+    const axios = mockAxios({
+      ttl: 127910 // random number
+    });
 
     const { headers } = await axios.get('url', {
       cache: { staleIfError: true }
     });
 
     expect(headers).toHaveProperty(Header.XAxiosCacheStaleIfError);
+    expect(headers[Header.XAxiosCacheStaleIfError]).toBe('127910');
   });
 
   it('expects staleIfError is ignore if config.cache is false', async () => {