Simple yet powerful HTTP mocking library for Rust
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## Features * Simple, expressive, fluent API. * Many built-in helpers for easy request matching ([Regex](https://docs.rs/regex/), JSON, [serde](https://crates.io/crates/serde), cookies, and more). * Record and Playback * Forward and Proxy Mode * HTTPS support * Fault and network delay simulation. * Custom request matchers. * Standalone mode with an accompanying [Docker image](https://hub.docker.com/r/alexliesenfeld/httpmock). * Helpful error messages * [Advanced verification and debugging support](https://alexliesenfeld.github.io/posts/mocking-http--services-in-rust/#creating-mocks) (including diff generation between actual and expected HTTP request values) * Parallel test execution. * Fully asynchronous core with synchronous and asynchronous APIs. * Support for [mock configuration using YAML files](https://github.com/alexliesenfeld/httpmock/tree/master#file-based-mock-specification). ## Getting Started Add `httpmock` to `Cargo.toml`: ```toml [dev-dependencies] httpmock = "0.8.0-alpha.1" ``` You can then use `httpmock` as follows: ```rust use httpmock::prelude::*; // Start a lightweight mock server. let server = MockServer::start(); // Create a mock on the server. let mock = server.mock(|when, then| { when.method(GET) .path("/translate") .query_param("word", "hello"); then.status(200) .header("content-type", "text/html; charset=UTF-8") .body("Привет"); }); // Send an HTTP request to the mock server. This simulates your code. let response = isahc::get(server.url("/translate?word=hello")).unwrap(); // Ensure the specified mock was called exactly one time (or fail with a // detailed error description). mock.assert(); // Ensure the mock server did respond as specified. assert_eq!(response.status(), 200); ``` The above example will spin up a lightweight HTTP mock server and configure it to respond to all `GET` requests to path `/translate` with query parameter `word=hello`. The corresponding HTTP response will contain the text body `Привет`. When the specified expectations do not match the received request, `httpmock` provides a detailed error description, including a diff that shows the differences between the expected and actual HTTP requests. Example: ```bash 0 of 1 expected requests matched the mock specification. Here is a comparison with the most similar unmatched request (request number 1): ------------------------------------------------------------ 1 : Query Parameter Mismatch ------------------------------------------------------------ Expected: key [equals] word value [equals] hello-rustaceans Received (most similar query parameter): word=hello All received query parameter values: 1. word=hello Matcher: query_param Docs: https://docs.rs/httpmock/0.8.0-alpha.1/httpmock/struct.When.html#method.query_param ``` # Usage See the [official website](http://alexliesenfeld.github.io/httpmock) for detailed API documentation. ## Examples You can find examples in the [`httpmock` test directory](https://github.com/alexliesenfeld/httpmock/blob/master/tests/). The [official website](http://alexliesenfeld.github.io/httpmock) and [reference docs](https://docs.rs/httpmock/) also contain _**a lot**_ of examples. ## License `httpmock` is free software: you can redistribute it and/or modify it under the terms of the MIT Public License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the MIT Public License for more details.