fix: resolve JSON parsing error and standardize HTTP client usage

- Fix JSON parsing error in getOrCreateGiteaOrg function (#19)
  - Add content-type validation before JSON parsing
  - Add response cloning for better error debugging
  - Enhance error messages with actual response content
  - Add comprehensive logging for troubleshooting

- Standardize HTTP client usage across codebase
  - Create new http-client.ts utility with consistent error handling
  - Replace all superagent calls with fetch-based functions
  - Replace all axios calls with fetch-based functions
  - Remove superagent, axios, and @types/superagent dependencies
  - Update tests to mock new HTTP client
  - Maintain backward compatibility

- Benefits:
  - Smaller bundle size (removed 3 HTTP client libraries)
  - Better performance (leveraging Bun's optimized fetch)
  - Consistent error handling across all HTTP operations
  - Improved debugging with detailed error messages
  - Easier maintenance with single HTTP client pattern

src/lib/gitea.test.ts

@@ -1,6 +1,7 @@
 import { describe, test, expect, mock, beforeEach, afterEach } from "bun:test";
 import { Octokit } from "@octokit/rest";
 import { repoStatusEnum } from "@/types/Repository";
+import { getOrCreateGiteaOrg } from "./gitea";
 
 // Mock the isRepoPresentInGitea function
 const mockIsRepoPresentInGitea = mock(() => Promise.resolve(false));
@@ -27,23 +28,17 @@ mock.module("@/lib/helpers", () => {
   };
 });
 
-// Mock superagent
-mock.module("superagent", () => {
-  const mockPost = mock(() => ({
-    set: () => ({
-      set: () => ({
-        send: () => Promise.resolve({ body: { id: 123 } })
-      })
-    })
-  }));
-
-  const mockGet = mock(() => ({
-    set: () => Promise.resolve({ body: [] })
-  }));
-
+// Mock http-client
+mock.module("@/lib/http-client", () => {
   return {
-    post: mockPost,
-    get: mockGet
+    httpPost: mock(() => Promise.resolve({ data: { id: 123 }, status: 200, statusText: 'OK', headers: new Headers() })),
+    httpGet: mock(() => Promise.resolve({ data: [], status: 200, statusText: 'OK', headers: new Headers() })),
+    HttpError: class MockHttpError extends Error {
+      constructor(message: string, public status: number, public statusText: string, public response?: string) {
+        super(message);
+        this.name = 'HttpError';
+      }
+    }
   };
 });
 
@@ -117,4 +112,96 @@ describe("Gitea Repository Mirroring", () => {
     // Check that the function was called
     expect(mirrorGithubRepoToGitea).toHaveBeenCalled();
   });
+
+  test("getOrCreateGiteaOrg handles JSON parsing errors gracefully", async () => {
+    // Mock fetch to return invalid JSON
+    const originalFetch = global.fetch;
+    global.fetch = mock(async (url: string) => {
+      if (url.includes("/api/v1/orgs/")) {
+        // Mock response that looks successful but has invalid JSON
+        return {
+          ok: true,
+          status: 200,
+          headers: {
+            get: (name: string) => name === "content-type" ? "application/json" : null
+          },
+          json: () => Promise.reject(new Error("Unexpected token in JSON")),
+          text: () => Promise.resolve("Invalid JSON response"),
+          clone: function() {
+            return {
+              text: () => Promise.resolve("Invalid JSON response")
+            };
+          }
+        } as any;
+      }
+      return originalFetch(url);
+    });
+
+    const config = {
+      userId: "user-id",
+      giteaConfig: {
+        url: "https://gitea.example.com",
+        token: "gitea-token"
+      }
+    };
+
+    try {
+      await getOrCreateGiteaOrg({
+        orgName: "test-org",
+        config
+      });
+      // Should not reach here
+      expect(true).toBe(false);
+    } catch (error) {
+      // Should catch the JSON parsing error with a descriptive message
+      expect(error).toBeInstanceOf(Error);
+      expect((error as Error).message).toContain("Failed to parse JSON response from Gitea API");
+    } finally {
+      // Restore original fetch
+      global.fetch = originalFetch;
+    }
+  });
+
+  test("getOrCreateGiteaOrg handles non-JSON content-type gracefully", async () => {
+    // Mock fetch to return HTML instead of JSON
+    const originalFetch = global.fetch;
+    global.fetch = mock(async (url: string) => {
+      if (url.includes("/api/v1/orgs/")) {
+        return {
+          ok: true,
+          status: 200,
+          headers: {
+            get: (name: string) => name === "content-type" ? "text/html" : null
+          },
+          text: () => Promise.resolve("<html><body>Error page</body></html>")
+        } as any;
+      }
+      return originalFetch(url);
+    });
+
+    const config = {
+      userId: "user-id",
+      giteaConfig: {
+        url: "https://gitea.example.com",
+        token: "gitea-token"
+      }
+    };
+
+    try {
+      await getOrCreateGiteaOrg({
+        orgName: "test-org",
+        config
+      });
+      // Should not reach here
+      expect(true).toBe(false);
+    } catch (error) {
+      // Should catch the content-type error
+      expect(error).toBeInstanceOf(Error);
+      expect((error as Error).message).toContain("Invalid response format from Gitea API");
+      expect((error as Error).message).toContain("text/html");
+    } finally {
+      // Restore original fetch
+      global.fetch = originalFetch;
+    }
+  });
 });