Crate test_generator

Overview

This crate provides #[test_resources] and #[bench_resources] procedural macro attributes that generates multiple parametrized tests using one body with different resource input parameters. A test is generated for each resource matching the specific resource location pattern.

Documentation

Repository

Getting Started

First of all you have to add this dependency to your Cargo.toml:

[dev-dependencies]
test-generator = "0.3.0"

With Rust older than 1.30, you have to enable proc_macro feature and include crate. You can do this globally by adding:

#![feature(proc_macro)]
extern crate test_generator;

Don't forget that procedural macros are imported with use statement:

use test_generator::test_resources;

Example usage test:

#![cfg(test)]
extern crate test_generator;

use test_generator::test_resources;

#[test_resources("res/*/input.txt")]
fn verify_resource(resource: &str) { assert!(std::path::Path::new(resource).exists()); }

Output from cargo test for 3 test-input-files matching the pattern, for this example:

$ cargo test

running 3 tests
test tests::verify_resource_res_set1_input_txt ... ok
test tests::verify_resource_res_set2_input_txt ... ok
test tests::verify_resource_res_set3_input_txt ... ok

test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

Example usage bench:

#![feature(test)] // nightly feature required for API test::Bencher

#[macro_use]
extern crate test_generator;

extern crate test; /* required for test::Bencher */

mod bench {
    #[bench_resources("res/*/input.txt")]
    fn measure_resource(b: &mut test::Bencher, resource: &str) {
        let path = std::path::Path::new(resource);
        b.iter(|| path.exists());
    }
}

Output from cargo +nightly bench for 3 bench-input-files matching the pattern, for this example:

running 3 tests
test bench::measure_resource_res_set1_input_txt ... bench:       2,492 ns/iter (+/- 4,027)
test bench::measure_resource_res_set2_input_txt ... bench:       2,345 ns/iter (+/- 2,167)
test bench::measure_resource_res_set3_input_txt ... bench:       2,269 ns/iter (+/- 1,527)

test result: ok. 0 passed; 0 failed; 0 ignored; 3 measured; 0 filtered out

Example

The example demonstrates usage and configuration of these macros, in combination with the crate build-deps monitoring for any change of these resource files and conditional rebuild.

Internals

Let's assume the following code and 3 files matching the pattern "res/*/input.txt"

#[test_resources("res/*/input.txt")]
fn verify_resource(resource: &str) { assert!(std::path::Path::new(resource).exists()); }

the generated code for this input resource will look like

#[test]
#[allow(non_snake_case)]
fn verify_resource_res_set1_input_txt() { verify_resource("res/set1/input.txt".into()); }
#[test]
#[allow(non_snake_case)]
fn verify_resource_res_set2_input_txt() { verify_resource("res/set2/input.txt".into()); }
#[test]
#[allow(non_snake_case)]
fn verify_resource_res_set3_input_txt() { verify_resource("res/set3/input.txt".into()); }

Note: The trailing into() method-call permits users to implement the Into-Trait for auto-conversations.

Macros

bench_expand_list	deprecated Generate a benchmark-function call for each list-element
bench_expand_paths	deprecated Generate a benchmark-function call for each file matching the pattern
glob_expand	deprecated Function-Attribute macro expanding glob-file-pattern to a list of directories and generating a test-function for each one.
test_expand_list	deprecated Generate a test-function call for each list-element
test_expand_paths	deprecated Generate a test-function call for each file matching the pattern

Attribute Macros

bench_resources	Macro generating bench-functions, invoking the fn for each item matching the resource-pattern.
test_resources	Macro generating test-functions, invoking the fn for each item matching the resource-pattern.