fix(ajax): retain response status in cached results

src/core/util/ajax.js

@@ -4,7 +4,7 @@ import progressbar from '../render/progressbar.js';
 import { noop } from './core.js';
 
 /** @typedef {{updatedAt: string}} CacheOpt */
-/** @typedef {{content: string, opt: CacheOpt}} CacheItem */
+/** @typedef {{content: string, opt: CacheOpt, response: ResponseStatus}} CacheItem */
 /** @typedef {{ok: boolean, status: number, statusText: string}} ResponseStatus */
 /** @type {Record<string, CacheItem>} */
 
@@ -30,7 +30,10 @@ export function get(url, hasBar = false, headers = {}) {
   const cached = cache[url];
 
   if (cached) {
-    return { then: cb => cb(cached.content, cached.opt), abort: noop };
+    return {
+      then: cb => cb(cached.content, cached.opt, cached.response),
+      abort: noop,
+    };
   }
 
   xhr.open('GET', url);
@@ -87,9 +90,10 @@ export function get(url, hasBar = false, headers = {}) {
             opt: {
               updatedAt: xhr.getResponseHeader('last-modified') ?? '',
             },
+            response: getResponseStatus(event),
           });
 
-          success(result.content, result.opt, getResponseStatus(event));
+          success(result.content, result.opt, result.response);
         }
       });
     },

test/unit/ajax.test.js

@@ -0,0 +1,30 @@
+import _mock from 'xhr-mock';
+import { get } from '../../src/core/util/ajax.js';
+
+const mock = _mock.default;
+
+describe('ajax/get', () => {
+  beforeEach(() => mock.setup());
+  afterEach(() => mock.teardown());
+
+  test('preserves response status when serving cached content', async () => {
+    const url = '/cached-response-status.md';
+    mock.get(url, { status: 200, body: '# Cached page' });
+
+    const first = await new Promise(resolve => {
+      get(url).then((content, opt, response) => {
+        resolve({ content, opt, response });
+      });
+    });
+    const cached = await new Promise(resolve => {
+      get(url).then((content, opt, response) => {
+        resolve({ content, opt, response });
+      });
+    });
+
+    expect(first.response).toEqual(
+      expect.objectContaining({ ok: true, status: 200 }),
+    );
+    expect(cached).toEqual(first);
+  });
+});