Test generator

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.

The following examples assume the package layout is as follows:

├── build.rs ├── Cargo.toml ├── LICENSE-APACHE ├── LICENSE-MIT ├── README.md ├── res │ ├── set1 │ │ ├── expect.txt │ │ └── input.txt │ ├── set2 │ │ ├── expect.txt │ │ └── input.txt │ └── set3 │ ├── expect.txt │ └── input.txt ├── src │ └── main.rs ├── benches │ └── mybenches.rs └── tests └── mytests.rs

Example usage `test`:

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

use testgenerator::testresources;

#[testresources("res/*/input.txt")] fn verifyresource(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::verifyresourceresset1inputtxt ... ok test tests::verifyresourceresset2inputtxt ... ok test tests::verifyresourceresset3input_txt ... ok

test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ``## Example usagebench`:

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

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

extern crate testgenerator; use testgenerator::bench_resources;

mod bench { #[benchresources("res/*/input.txt")] fn measureresource(b: &mut test::Bencher, resource: &str) { let path = std::path::Path::new(resource); b.iter(|| path.exists()); } } ``Output fromcargo +nightly bench` for 3 bench-input-files matching the pattern, for this example:

``` running 3 tests test bench::measureresourceresset1inputtxt ... bench: 2,492 ns/iter (+/- 4,027) test bench::measureresourceresset2inputtxt ... bench: 2,345 ns/iter (+/- 2,167) test bench::measureresourceresset3input_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.

Conditional Build Process

The Test-Funciton-Generator shall be rerun every time a new resource-file is added or one of the existing ones have been changed.

The conditional build can be realized using the crate build-deps, that is combining the functionality of the crates build-helper and glob. The user specifies a directory or a set of files, or a a filter-pattern to be watched by cargo process shall for changes. In case of changes, the build-process of the Rust-sources is re-run.

The following diagram illustrates the integration of the build-script into the conditional cargo build-process.

GLOB Filter Pattern Examples

The filter may be a glob-pattern containing wildcards, for example:

"res/*" will enumerate all files/directories in directory "res/" and watching changes

"res/" - will add the directory itself to the watch-list, triggering a rerun in case new entities are added.

"res/**/*.protobuf" will traverse all sub-directories enumerating all protobuf files.