Module testing 

Test utilities for fastapi applications.

This module provides a TestClient for in-process testing of handlers without network overhead. It integrates with asupersync’s capability model and supports deterministic testing via the Lab runtime.

Features

• In-process testing: No network I/O, fast execution
• HTTP-like API: Familiar client.get("/path") interface
• Request builder: Fluent API for headers, body, cookies
• Response assertions: Convenient assertion helpers
• Cookie jar: Automatic session management across requests
• Lab integration: Deterministic testing with asupersync

Example

use fastapi_core::testing::TestClient;
use fastapi_core::middleware::Handler;

async fn hello_handler(ctx: &RequestContext, req: &mut Request) -> Response {
    Response::ok().body(ResponseBody::Bytes(b"Hello, World!".to_vec()))
}

#[test]
fn test_hello() {
    let client = TestClient::new(hello_handler);
    let response = client.get("/hello").send();

    assert_eq!(response.status().as_u16(), 200);
    assert_eq!(response.text(), "Hello, World!");
}

Deterministic Testing

For reproducible tests involving concurrency, use TestClient::with_seed:

let client = TestClient::with_seed(handler, 42);
// Same seed = same execution order for concurrent operations

Macros

assert_eq_with_logs

Assertion helper that includes log context for equality checks.

assert_with_logs

Assertion helper that includes log context on failure.

e2e_test

Macro for defining E2E test scenarios with a declarative syntax.

Structs

CancellationTest

Helper for testing handler cancellation behavior.

CancellationTestResult

Result of a cancellation test.

CapturedLog

A captured log entry for test assertions.

CookieJar

A simple cookie jar for maintaining cookies across requests.

E2ECapture

A captured HTTP request/response pair from an E2E step.

E2EReport

E2E test report with multiple output formats.

E2EScenario

E2E test scenario builder and executor.

E2EStep

A single step in an E2E test scenario.

FixtureGuard

A guard that automatically calls teardown when dropped.

IntegrationTest

Context for integration tests that manages fixtures and test client.

IntegrationTestContext

Context available during an integration test.

LabTestConfig

Configuration for Lab-based deterministic testing.

LogCapture

Result of a log capture operation.

MockResponse

Configuration for a canned response.

MockServer

A mock HTTP server for integration testing.

MockServerOptions

Options for configuring a MockServer.

MockTime

Virtual time utilities for testing timeouts and delays.

RecordedRequest

A recorded request from the mock server.

RequestBuilder

Builder for constructing test requests with a fluent API.

ResponseDiff

Request/response diff helper for test assertions.

ResponseSnapshot

A serializable snapshot of an HTTP response for fixture-based testing.

TestChaosStats

Statistics about chaos injection during a test.

TestClient

Test client for in-process HTTP testing.

TestLogger

Test logger that captures logs for per-test isolation and assertions.

TestResponse

Response from a test request with assertion helpers.

TestServer

A real HTTP test server that routes requests through the full App pipeline.

TestServerConfig

Configuration for TestServer.

TestServerLogEntry

A log entry recorded by TestServer for each processed request.

TestTimings

Timing breakdown for test phases.

Enums

E2EStepResult

Result of executing an E2E step.

Traits

IntoStatusU16

Helper trait to convert various types to u16 for status code comparison.

TestFixture

Trait for test fixtures that set up and tear down test data.

Functions

json_contains

Checks if actual contains all fields from expected.