From 362ee0e2e9700324bef743bc161dcbc14b28ce9f Mon Sep 17 00:00:00 2001
From: Lars den Bakker <larsdenbakker@gmail.com>
Date: Thu, 26 May 2022 19:15:51 +0200
Subject: [PATCH] fix(ajax): align intercepted and non-intercepted response
 behavior

---
 .changeset/eight-years-pump.md  |  2 +-
 .changeset/soft-trains-brush.md |  5 +++++
 packages/ajax/src/Ajax.js       | 17 +++++++++++++++--
 packages/ajax/test/Ajax.test.js | 24 ++++++++++++++++++++++++
 4 files changed, 45 insertions(+), 3 deletions(-)
 create mode 100644 .changeset/soft-trains-brush.md

diff --git a/.changeset/eight-years-pump.md b/.changeset/eight-years-pump.md
index bd9967cd7..0d9a3285d 100644
--- a/.changeset/eight-years-pump.md
+++ b/.changeset/eight-years-pump.md
@@ -1,5 +1,5 @@
 ---
-"@lion/overlays": patch
+'@lion/overlays': patch
 ---
 
 fix: isVisible check on elements with display:contents
diff --git a/.changeset/soft-trains-brush.md b/.changeset/soft-trains-brush.md
new file mode 100644
index 000000000..11ea4ab70
--- /dev/null
+++ b/.changeset/soft-trains-brush.md
@@ -0,0 +1,5 @@
+---
+'@lion/ajax': patch
+---
+
+Align intercepted and non-intercepted response behavior
diff --git a/packages/ajax/src/Ajax.js b/packages/ajax/src/Ajax.js
index 663a65b5a..94f292482 100644
--- a/packages/ajax/src/Ajax.js
+++ b/packages/ajax/src/Ajax.js
@@ -7,6 +7,14 @@ import {
 import { AjaxFetchError } from './AjaxFetchError.js';
 import './typedef.js';
 
+/**
+ * @param {Response} response
+ * @returns {boolean}
+ */
+function isFailedResponse(response) {
+  return response.status >= 400 && response.status < 600;
+}
+
 /**
  * A small wrapper around `fetch`.
 - Allows globally registering request and response interceptors
@@ -115,8 +123,13 @@ export class Ajax {
     // run request interceptors, returning directly and skipping the network
     const interceptedRequestOrResponse = await this.__interceptRequest(request);
     if (interceptedRequestOrResponse instanceof Response) {
+      const response = /** @type {CacheResponse} */ (interceptedRequestOrResponse);
+      response.request = request;
+      if (isFailedResponse(interceptedRequestOrResponse)) {
+        throw new AjaxFetchError(request, response);
+      }
       // prevent network request, return cached response
-      return interceptedRequestOrResponse;
+      return response;
     }
 
     const response = /** @type {CacheResponse} */ (await fetch(interceptedRequestOrResponse));
@@ -124,7 +137,7 @@ export class Ajax {
 
     const interceptedResponse = await this.__interceptResponse(response);
 
-    if (interceptedResponse.status >= 400 && interceptedResponse.status < 600) {
+    if (isFailedResponse(interceptedResponse)) {
       throw new AjaxFetchError(request, interceptedResponse);
     }
     return interceptedResponse;
diff --git a/packages/ajax/test/Ajax.test.js b/packages/ajax/test/Ajax.test.js
index 1ab548f29..f9f84f608 100644
--- a/packages/ajax/test/Ajax.test.js
+++ b/packages/ajax/test/Ajax.test.js
@@ -257,6 +257,30 @@ describe('Ajax', () => {
       const text = await response.text();
       expect(text).to.equal('mock response');
     });
+
+    it('returns the original request object', async () => {
+      ajax.addRequestInterceptor(async () => new Response('my response', { status: 200 }));
+
+      const response = /** @type {CacheResponse} */ (await await ajax.fetch('/foo'));
+      expect(response.request).to.be.an.instanceOf(Request);
+    });
+
+    it('throws on 4xx responses returned from request interceptor', async () => {
+      ajax.addRequestInterceptor(async () => new Response('my response', { status: 400 }));
+
+      let thrown = false;
+      try {
+        await ajax.fetch('/foo');
+      } catch (e) {
+        // https://github.com/microsoft/TypeScript/issues/20024 open issue, can't type catch clause in param
+        const _e = /** @type {AjaxFetchError} */ (e);
+        expect(_e).to.be.an.instanceOf(AjaxFetchError);
+        expect(_e.request).to.be.an.instanceOf(Request);
+        expect(_e.response).to.be.an.instanceOf(Response);
+        thrown = true;
+      }
+      expect(thrown).to.be.true;
+    });
   });
 
   describe('accept-language header', () => {