Vault: handle empty delete responses (#913)

Co-authored-by: Viet Tran <viettranx@gmail.com>

ui/web/src/api/http-client.test.ts

@@ -0,0 +1,48 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { HttpClient } from "./http-client";
+
+function createClient() {
+  return new HttpClient("https://example.com", () => "", () => "");
+}
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+  localStorage.clear();
+});
+
+describe("HttpClient", () => {
+  it("returns undefined for 204 no-content responses", async () => {
+    const fetchMock = vi.fn().mockResolvedValue(new Response(null, { status: 204, statusText: "No Content" }));
+    vi.stubGlobal("fetch", fetchMock as unknown as typeof fetch);
+
+    const client = createClient();
+    const result = await client.delete<void>("/v1/vault/documents/123");
+
+    expect(result).toBeUndefined();
+    expect(fetchMock).toHaveBeenCalledWith(
+      "https://example.com/v1/vault/documents/123",
+      expect.objectContaining({
+        method: "DELETE",
+        headers: expect.objectContaining({
+          "Content-Type": "application/json",
+        }),
+      }),
+    );
+  });
+
+  it("parses JSON responses from successful requests", async () => {
+    const payload = { deleted: true };
+    const fetchMock = vi.fn().mockResolvedValue(
+      new Response(JSON.stringify(payload), {
+        status: 200,
+        headers: { "content-type": "application/json" },
+      }),
+    );
+    vi.stubGlobal("fetch", fetchMock as unknown as typeof fetch);
+
+    const client = createClient();
+    const result = await client.post<{ deleted: boolean }>("/v1/test", { id: "123" });
+
+    expect(result).toEqual(payload);
+  });
+});

ui/web/src/api/http-client.ts

@@ -90,7 +90,7 @@ export class HttpClient {
       throw new ApiError(code, message);
     }
 
-    return res.json() as Promise<T>;
+    return this.readJson<T>(res);
   }
 
   private buildUrl(path: string, params?: Record<string, string>): string {
@@ -150,6 +150,19 @@ export class HttpClient {
       throw new ApiError(code, message);
     }
 
-    return res.json() as Promise<T>;
+    return this.readJson<T>(res);
+  }
+
+  private async readJson<T>(res: Response): Promise<T> {
+    if (res.status === 204 || res.headers.get("content-length") === "0") {
+      return undefined as T;
+    }
+
+    const text = await res.text();
+    if (text.trim().length === 0) {
+      return undefined as T;
+    }
+
+    return JSON.parse(text) as T;
   }
 }