> ## Documentation Index > Fetch the complete documentation index at: https://easyaf.dev/llms.txt > Use this file to discover all available pages before exploring further. # Why Breakdance? > Understand the philosophy behind Test Real Things and why Breakdance eliminates mocking from your test suite. ## The Mocking Trap Every .NET developer knows the pattern: create an interface, inject dependencies, mock everything in tests. It sounds clean. It feels testable. But it creates a fundamental problem: **Your tests pass in a universe that doesn't exist.** Mocks are imagination codified. They represent what you *think* an API returns, how you *assume* an error manifests, what you *hope* the edge cases look like. When your imagination doesn't match reality, your tests become lies that pass with green checkmarks. ## The Real Cost of Mocks Every API change requires updating mock configurations across your test suite. Miss one spot, and your tests still pass while your production code fails. The larger your codebase, the more mock maintenance becomes a full-time job. Green tests feel good. They signal "everything works." But mock-based tests only prove your code works with your mocks. They say nothing about whether your code works with real services, real data, or real edge cases. Real APIs return unexpected data. Null values where you expected objects. Arrays when you expected singles. Error messages in formats you didn't anticipate. Mocks can't capture what you don't know to mock. APIs evolve. External services add fields, deprecate endpoints, change error formats. Your mocks stay frozen in time, creating an ever-widening gap between what tests verify and what production encounters. ## A Different Philosophy Breakdance is built on a simple belief: **tests should exercise real behavior, not imagined behavior.** Instead of writing mock configurations that describe what you think will happen, Breakdance helps you capture what actually happens and replay it in your tests. Record real HTTP responses, real API behaviors, real edge cases from actual systems. Store them as snapshot files alongside your tests. Your tests read from these snapshots instantly - no network calls, no rate limits, no flaky dependencies. Fast, deterministic, and offline-capable. ## What "Test Real Things" Means When you test HTTP client code, use actual responses captured from real APIs. Your code parses the same JSON, handles the same edge cases, and encounters the same quirks as production. When you test Azure Storage code, use Azurite - a real Azure Storage emulator that behaves identically to the cloud service. Not a mock, not a stub - the actual storage API. When you test ASP.NET APIs, use TestServer to run your actual middleware, routing, and controller logic in-memory. Same code, same DI container, same behavior. When you define test requests, use the `.http` file format - the same format Visual Studio and VS Code use. Human-readable, portable, and immediately executable. ## The Snapshot Workflow The Breakdance workflow replaces mock maintenance with snapshot management: ```mermaid theme={"dark"} graph LR A[Real API] -->|Capture| B[Snapshot File] B -->|Replay| C[Your Tests] C -->|Fast & Deterministic| D[CI/CD Pipeline] A -->|API Changes| E[Re-capture] E -->|Diff Reveals| F[Breaking Changes] ``` 1. **Capture**: Run your code against real APIs once. Breakdance saves responses to files. 2. **Commit**: Check snapshot files into source control with your tests. 3. **Replay**: Tests read from files instantly. No network, no secrets needed. 4. **Refresh**: When APIs change, re-capture. Git diff shows exactly what changed. ## When to Use What | Scenario | Breakdance Approach | | ------------------------- | -------------------------------------------------------------- | | Testing HTTP client code | Response Snapshots - capture and replay real API responses | | Testing your own APIs | In-memory TestServer - run your actual ASP.NET pipeline | | Testing Azure Storage | Azurite integration - real storage API, local execution | | Documenting API contracts | Request Snapshots - `.http` files that serve as tests and docs | | CI/CD without secrets | All approaches - snapshots eliminate external dependencies | ## What Breakdance Doesn't Do Breakdance isn't against all forms of test isolation. There are legitimate cases for: * **Seams for DI**: Constructor injection for swapping implementations * **In-memory databases**: EF Core's in-memory provider for data tests * **Test fixtures**: Setup and teardown for stateful resources What Breakdance eliminates is **behavioral mocking** - the practice of writing code that pretends to be something else. Instead of `mockHttp.Setup(x => x.GetAsync(...)).Returns(...)`, you capture what `GetAsync` actually returns. ## The Result Teams using Breakdance report: Snapshot replay is instant. No network latency, no external service slowdowns. Production issues that mocks would have hidden surface during development. Refreshing snapshots is faster than updating mock configurations. ## Ready to Break Free? Start with the concept that fits your current testing pain: Learn how Response Snapshots capture and replay real HTTP responses. Test your controllers with in-memory TestServer - no deployment needed. Test against real Azurite instead of mocking storage operations. Understand the complete "Test Real Things" philosophy and workflow.