# End-to-End Tests

Integration tests that spin up real gost instances inside Docker containers and verify protocol behavior over the network.

## Prerequisites

- [Docker](https://docs.docker.com/get-docker/) (running daemon)
- Go toolchain (for compiling the gost binary under test)

## Running

From the repository root:

```bash
# Run all e2e tests
go test ./tests/e2e/ -v -timeout 10m

# Run a specific test suite
go test ./tests/e2e/ -v -run TestShadowsocksSuite -timeout 5m
go test ./tests/e2e/ -v -run TestParallelSelectorSuite -timeout 5m

# Use a pre-built gost binary (skips compilation)
go test ./tests/e2e/ -v -gost-bin /path/to/gost
```

## Architecture

```
tests/e2e/
├── Dockerfile                  # Shared base image (Alpine + curl, python3, etc.)
├── main_test.go                # TestMain: compiles gost, creates Docker network
├── utils.go                    # Helpers: container lifecycle, config rendering
├── scripts/
│   ├── tcp_echo.py             # HTTP echo server (responds with "hello-gost")
│   └── udp_echo.py             # UDP echo server (reflects payloads)
├── testdata/                   # config files or data files for running cases
├── shadowsocks_test.go         # Shadowsocks protocol tests
└── parallel_selector_test.go   # Parallel node selector tests
```

### How it works

1. **TestMain** (`main_test.go`) compiles the gost binary from `../../cmd/gost` (unless `-gost-bin` is provided) and creates a shared Docker network for all containers.
2. Each test suite starts echo server containers (TCP/UDP), then launches separate gost containers for server and client roles.
3. Client configs use Go template syntax (`{{.ServerAddr}}`) so the server address is injected at runtime.
4. Tests verify end-to-end connectivity by sending traffic through the gost proxy chain and checking that the echo server responds correctly.

## Tips

- Increase `-timeout` for CI or slow networks. Container image builds on first run take extra time.
- Use `-gost-bin` to avoid recompiling when iterating on tests locally.
- Add `-v` to see container log output on failure.
- RunGostContainer will wait for exposedPorts automatically, but it's not reliable for udp ports. So, you should check the readiness of udp ports inside cases.