Testing

Aether is designed to be testable. You can write unit tests for your logic and integration tests for your full application.

Unit Testing

Since most logic resides in commonMain, you can use standard kotlin.test assertions.

Aether apps are easy to test using standard tools like JUnit and MockK.

Testing Handlers

You can mock the Exchange object to test handlers in isolation.

@Test
fun testHelloHandler() = runTest {
    val exchange = MockExchange(path = "/hello/world")
    val handler = { ex: Exchange -> 
        ex.respond(body = "Hello") 
    }
    
    handler(exchange)
    
    assertEquals(200, exchange.response.statusCode)
    assertEquals("Hello", exchange.response.bodyString)
}

End-to-End (E2E) Testing

For integration testing, you can spin up a real server instance within your test suite.

@Test
fun testServer() {
    val server = VertxServer.create(port = 0) {
        it.respond("OK")
    }
    runBlocking {
        server.start()
        // Use an HTTP client to test endpoints
        server.stop()
    }
}

Using testcontainers is recommended for testing with real database backends.

Integration Testing

Integration tests run the full server stack. Aether uses TestContainers to spin up dependencies like PostgreSQL.

Setup

Add the test dependencies in build.gradle.kts:

dependencies {
    testImplementation(libs.testcontainers.postgresql)
    testImplementation(libs.testcontainers.junit.jupiter)
}

Writing an Integration Test

@Testcontainers
class UserIntegrationTest {

    companion object {
        @Container
        val postgres = PostgreSQLContainer("postgres:16-alpine")
        
        @JvmStatic
        @BeforeAll
        fun setup() {
            // Configure Aether to use the container's JDBC URL
            DatabaseDriverRegistry.register(
                PostgresDriver(
                    url = postgres.jdbcUrl,
                    user = postgres.username,
                    password = postgres.password
                )
            )
        }
    }

    @Test
    fun `should create and retrieve user`() = runTest {
        // 1. Start Server (or use TestClient directly against Pipeline)
        val app = TestApplication()
        
        // 2. Perform Request
        val response = app.client.post("/users", json = """{"name": "Alice"}""")
        
        // 3. Assert
        assertEquals(201, response.statusCode)
        
        val user = Users.get(1)
        assertNotNull(user)
        assertEquals("Alice", user.name)
    }
}

Wasm Testing

Wasm tests run in a headless browser (Chrome/Firefox) or Node.js.

./gradlew wasmJsBrowserTest

Ensure you have the necessary browsers installed or configured in Karma.