From 468a076cd9a2fe2aa365527fde29f4bdb6682c52 Mon Sep 17 00:00:00 2001
From: soyuka <soyuka@users.noreply.github.com>
Date: Sat, 4 Jul 2026 10:55:27 +0200
Subject: [PATCH] fix(hydra): send default Accept header when options is an
 empty object

setHeaders() short-circuited on falsy options.headers, returning a
plain {} instead of building Headers with the Accept default. This
broke @api-platform/admin's schemaAnalyzer, which always calls
getParameters() with an explicit {} (see #177).
Removed the early return so the function always falls through to the
Headers/Accept logic, and swapped the headers derivation to avoid
mutating the caller's options object as a side effect.
---
 src/hydra/fetchJsonLd.test.ts | 34 ++++++++++++++++++++++++++++++++++
 src/hydra/fetchJsonLd.ts      |  8 +++-----
 2 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/src/hydra/fetchJsonLd.test.ts b/src/hydra/fetchJsonLd.test.ts
index 68c168e..ce9f4f7 100644
--- a/src/hydra/fetchJsonLd.test.ts
+++ b/src/hydra/fetchJsonLd.test.ts
@@ -154,6 +154,40 @@ test("fetch an error with Content-Type application/error+json", async () => {
   );
 });
 
+test("fetch with an explicit empty options object still sends the default Accept header", async () => {
+  let receivedAccept: string | null = null;
+
+  server.use(
+    http.get("http://localhost/foo.jsonld", ({ request }) => {
+      receivedAccept = request.headers.get("Accept");
+      return Response.json(httpResponse, {
+        headers: { "Content-Type": "application/ld+json" },
+        status: 200,
+        statusText: "OK",
+      });
+    }),
+  );
+
+  await fetchJsonLd("http://localhost/foo.jsonld", {});
+  expect(receivedAccept).toBe("application/ld+json");
+});
+
+test("fetch does not mutate the passed options object", async () => {
+  server.use(
+    http.get("http://localhost/foo.jsonld", () =>
+      Response.json(httpResponse, {
+        headers: { "Content-Type": "application/ld+json" },
+        status: 200,
+        statusText: "OK",
+      }),
+    ),
+  );
+
+  const options = {};
+  await fetchJsonLd("http://localhost/foo.jsonld", options);
+  expect(options).toEqual({});
+});
+
 test("fetch an empty document", async () => {
   server.use(
     http.get(
diff --git a/src/hydra/fetchJsonLd.ts b/src/hydra/fetchJsonLd.ts
index 99be05c..349e707 100644
--- a/src/hydra/fetchJsonLd.ts
+++ b/src/hydra/fetchJsonLd.ts
@@ -61,12 +61,10 @@ export default async function fetchJsonLd(
 }
 
 function setHeaders(options: RequestInitExtended): RequestInit {
-  if (!options.headers) {
-    return { ...options, headers: {} };
-  }
-
   let headers =
-    typeof options.headers === "function" ? options.headers() : options.headers;
+    typeof options.headers === "function"
+      ? options.headers()
+      : (options.headers ?? {});
 
   headers = new Headers(headers);