Test generator UTest

This crates implements a 3-phase utest-harness for Rust. The 3 phases are:

• Setup: the setup function must initialize the context; in case the function panics/aborts, the utest is aborted fn() -> Context
• Test: if the setup did return with valud context item, this context is used to invoke the test. fn( & Context )
• Teardown: no matter if the test-function above did panic/abort, the teardown function is invoked to release the context fn( Context )

No matter of any panic or failing assertion in the second phase (feature testing), the teardown function is invoked. The test will either succeed, or otherwise unwinding a failure in the setup-phase, the test-phase or the teardown-phase.

This crate has been inspired by the post of Eric Opines.

Usage

Please see the test file 'mytests.rs at the executable example.

```rust

[cfg(test)]

extern crate testgeneratorutest;

// demonstrating usage of utest-harness mod testsuite { use std::fs::File; use std::io::prelude::*;

use test_generator_utest::utest;

// Defining a context structure, storing the resources
struct Context<'t> { file: File, name: &'t str }

// Setup - Initializing the resources
fn setup<'t>(filename: &str) -> Context {
    // unwrap may panic
    Context { file: File::create(filename).unwrap(), name: filename }
}

// Teardown - Releasing the resources
fn teardown(context: Context) {
    let Context { file, name } = context;

    // drop file resources
    std::mem::drop(file);

    // unwrap may panic
    std::fs::remove_file(name).unwrap();
}

// Test - verify feature
fn test_write_hello_world(ctx: &Context) {
    // may panic
    let mut file = ctx.file.try_clone().unwrap();

    // may panic
    file.write_all(b"Hello, world!\n").unwrap();
}

// Test - verify feature
fn test_write_hello_europe(ctx: &Context) {
    // may panic
    let mut file = ctx.file.try_clone().unwrap();

    // may panic
    file.write_all(b"Hello, Europe!\n").unwrap();
}

// Defining Utest formed by setup, test and teardown
utest!(hello_world,
    || setup("/tmp/hello_world.txt"),
    |ctx_ref| test_write_hello_world(ctx_ref),
    |ctx|teardown(ctx));


// Defining Utest formed by setup, test and teardown
utest!(hello_europe,
    || setup("/tmp/hello_europe.txt"),
    test_write_hello_europe,
    teardown);

} ```

Executing the example code cargo test -p test-generator-example testsuite the testsuote above will print the following output.

``` running 2 tests test testsuite::helloeurope ... ok test testsuite::helloworld ... ok

test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 3 filtered out ```