[](https://github.com/frehberg/test-generator/blob/master/LICENSE-MIT)
[](https://github.com/frehberg/test-generator/blob/master/LICENSE-APACHE)
# 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 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
extern crate test; /* required for test::Bencher */
extern crate test_generator;
use test_generator::bench_resources;
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](https://github.com/frehberg/test-generator/tree/master/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.
`"res/**"` will traverse all sub-directories enumerating all directories