frontend/src/lib/__tests__/api.test.ts

@@ -0,0 +1,117 @@
+/**
+ * Tests for `apiFetch` — regression coverage для issue #1219.
+ *
+ * Bug: `apiFetch` безусловно звал `response.json()` после `response.ok`-check,
+ * что падало с `SyntaxError: Unexpected end of JSON input` на 204 No Content
+ * (DELETE /api/v1/custom-pois/{id}, DELETE /api/v1/admin/site-finder/weight-
+ * profiles/{id}). Промис мутации реджектился → onSuccess/invalidateQueries не
+ * срабатывали → UI рассинхронизировался с сервером (объект удалён, но виден).
+ *
+ * Fix: на 204 / пустом теле resolve'имся с undefined (см. api.ts:apiFetch).
+ */
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { apiFetch } from "../api";
+
+// Минимальный mock Response — fetch global под jsdom есть, но контролируем
+// status/body точечно через vi.stubGlobal.
+function mockResponse(init: {
+  status: number;
+  body?: string;
+  ok?: boolean;
+}): Response {
+  const { status, body = "", ok = status >= 200 && status < 300 } = init;
+  return {
+    ok,
+    status,
+    text: () => Promise.resolve(body),
+    json: () =>
+      body
+        ? Promise.resolve(JSON.parse(body))
+        : Promise.reject(new SyntaxError("Unexpected end of JSON input")),
+  } as unknown as Response;
+}
+
+describe("apiFetch — 204 No Content handling (#1219)", () => {
+  beforeEach(() => {
+    vi.stubGlobal("fetch", vi.fn());
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+    vi.restoreAllMocks();
+  });
+
+  it("resolves with undefined on 204 No Content (empty body)", async () => {
+    vi.mocked(fetch).mockResolvedValueOnce(
+      mockResponse({ status: 204, body: "" }),
+    );
+
+    const result = await apiFetch<unknown>("/api/v1/custom-pois/42", {
+      method: "DELETE",
+    });
+
+    expect(result).toBeUndefined();
+  });
+
+  it("does not throw SyntaxError on 204 (regression guard)", async () => {
+    vi.mocked(fetch).mockResolvedValueOnce(
+      mockResponse({ status: 204, body: "" }),
+    );
+
+    await expect(
+      apiFetch<unknown>("/api/v1/custom-pois/42", { method: "DELETE" }),
+    ).resolves.toBeUndefined();
+  });
+
+  it("resolves with parsed JSON on 200 OK with body", async () => {
+    const payload = { id: 1, name: "Test POI", lat: 56.83, lon: 60.6 };
+    vi.mocked(fetch).mockResolvedValueOnce(
+      mockResponse({ status: 200, body: JSON.stringify(payload) }),
+    );
+
+    const result = await apiFetch<typeof payload>("/api/v1/custom-pois/1");
+
+    expect(result).toEqual(payload);
+  });
+
+  it("resolves with undefined on 200 OK with empty body (defensive)", async () => {
+    // Не-стандартно (200 + empty), но возможно для некоторых прокси/edge cases.
+    // До фикса падало тем же SyntaxError что и 204.
+    vi.mocked(fetch).mockResolvedValueOnce(
+      mockResponse({ status: 200, body: "" }),
+    );
+
+    const result = await apiFetch<unknown>("/api/v1/something");
+
+    expect(result).toBeUndefined();
+  });
+
+  it("throws on 4xx with detail body included", async () => {
+    vi.mocked(fetch).mockResolvedValueOnce(
+      mockResponse({
+        status: 404,
+        body: JSON.stringify({ detail: "POI not found" }),
+        ok: false,
+      }),
+    );
+
+    await expect(
+      apiFetch<unknown>("/api/v1/custom-pois/999", { method: "DELETE" }),
+    ).rejects.toThrow(/API error 404/);
+  });
+
+  it("throws on 5xx", async () => {
+    vi.mocked(fetch).mockResolvedValueOnce(
+      mockResponse({
+        status: 500,
+        body: "Internal Server Error",
+        ok: false,
+      }),
+    );
+
+    await expect(apiFetch<unknown>("/api/v1/foo")).rejects.toThrow(
+      /API error 500/,
+    );
+  });
+});

frontend/src/lib/api.ts

@@ -38,7 +38,19 @@ export async function apiFetch<T>(
   if (!response.ok) {
     throw new Error(`API error ${response.status}: ${await response.text()}`);
   }
-  return response.json() as Promise<T>;
+  // 204 No Content / пустое тело: `response.json()` бросит SyntaxError на пустой
+  // строке. Читаем как text один раз (stream consumable только раз) и парсим
+  // JSON только если непусто. На 204 / empty resolve'имся с undefined — caller
+  // для DELETE/no-content endpoints его игнорирует. Аналог поведения
+  // apiFetchWithStatus (см. ниже). Issue #1219.
+  if (response.status === 204) {
+    return undefined as T;
+  }
+  const rawText = await response.text();
+  if (!rawText) {
+    return undefined as T;
+  }
+  return JSON.parse(rawText) as T;
 }
 
 /**