feat: migrate testing framework to Bun and update test configurations

- Updated GitHub Actions workflow to use Bun's test runner and coverage reporting.
- Added comprehensive testing documentation for the Gitea Mirror project.
- Refactored test scripts in package.json to align with Bun's testing commands.
- Created new test files for database, Gitea, GitHub, health, and mirroring APIs.
- Implemented mock functions for API tests to handle various scenarios and responses.
- Established a test setup file for consistent test environment configuration.

src/pages/api/github/test-connection.test.ts

@@ -0,0 +1,133 @@
+import { describe, test, expect, mock, beforeEach, afterEach } from "bun:test";
+import { POST } from "./test-connection";
+import { Octokit } from "@octokit/rest";
+
+// Mock the Octokit class
+mock.module("@octokit/rest", () => {
+  return {
+    Octokit: mock(function() {
+      return {
+        users: {
+          getAuthenticated: mock(() => Promise.resolve({
+            data: {
+              login: "testuser",
+              name: "Test User",
+              avatar_url: "https://example.com/avatar.png"
+            }
+          }))
+        }
+      };
+    })
+  };
+});
+
+describe("GitHub Test Connection API", () => {
+  // Mock console.error to prevent test output noise
+  let originalConsoleError: typeof console.error;
+  
+  beforeEach(() => {
+    originalConsoleError = console.error;
+    console.error = mock(() => {});
+  });
+  
+  afterEach(() => {
+    console.error = originalConsoleError;
+  });
+  
+  test("returns 400 if token is missing", async () => {
+    const request = new Request("http://localhost/api/github/test-connection", {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json"
+      },
+      body: JSON.stringify({})
+    });
+    
+    const response = await POST({ request } as any);
+    
+    expect(response.status).toBe(400);
+    
+    const data = await response.json();
+    expect(data.success).toBe(false);
+    expect(data.message).toBe("GitHub token is required");
+  });
+  
+  test("returns 200 with user data on successful connection", async () => {
+    const request = new Request("http://localhost/api/github/test-connection", {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json"
+      },
+      body: JSON.stringify({
+        token: "valid-token"
+      })
+    });
+    
+    const response = await POST({ request } as any);
+    
+    expect(response.status).toBe(200);
+    
+    const data = await response.json();
+    expect(data.success).toBe(true);
+    expect(data.message).toBe("Successfully connected to GitHub as testuser");
+    expect(data.user).toEqual({
+      login: "testuser",
+      name: "Test User",
+      avatar_url: "https://example.com/avatar.png"
+    });
+  });
+  
+  test("returns 400 if username doesn't match authenticated user", async () => {
+    const request = new Request("http://localhost/api/github/test-connection", {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json"
+      },
+      body: JSON.stringify({
+        token: "valid-token",
+        username: "differentuser"
+      })
+    });
+    
+    const response = await POST({ request } as any);
+    
+    expect(response.status).toBe(400);
+    
+    const data = await response.json();
+    expect(data.success).toBe(false);
+    expect(data.message).toBe("Token belongs to testuser, not differentuser");
+  });
+  
+  test("handles authentication errors", async () => {
+    // Mock Octokit to throw an error
+    mock.module("@octokit/rest", () => {
+      return {
+        Octokit: mock(function() {
+          return {
+            users: {
+              getAuthenticated: mock(() => Promise.reject(new Error("Bad credentials")))
+            }
+          };
+        })
+      };
+    });
+    
+    const request = new Request("http://localhost/api/github/test-connection", {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json"
+      },
+      body: JSON.stringify({
+        token: "invalid-token"
+      })
+    });
+    
+    const response = await POST({ request } as any);
+    
+    expect(response.status).toBe(500);
+    
+    const data = await response.json();
+    expect(data.success).toBe(false);
+    expect(data.message).toContain("Bad credentials");
+  });
+});