# RUN Test (RUNT)   [![latest]][crate]
[latest]: https://img.shields.io/crates/v/runt.svg
[crate]: https://crates.io/crates/runt
Runt is a lightweight, parallel snapshot testing framework. It aims to enable
snapshot testing with minimal configuration.
Install the latest version of `runt` using:
```
cargo install runt
```
Runt is most useful when you have the following test setup:
- One command that needs to run on many input files.
- Test suites grouped by commands run on the files.
- Test outputs are sent to IO streams (stdout and stderr).
- Test and test suites are unordered.
Runt is not useful when you want to do:
- Rich introspective testing of data structures.
- Test suites with complex setups, dependencies, and teardowns.
Snapshot testing with runt is extremely flexible. For example, the tests
under `runt-cli-test` test the outputs of the runt CLI.
### Building & Developing
- Install [Rust][].
- Run `cargo build --release`. The `runt` executable is generated
under `target/release/runt`.
- Runt is tested using `runt`. Run `runt runt-cli-test` to test runt.
### Configuration
Runt is configured using a single `runt.toml` file:
```toml
# Runts support multiple test suites.
[[tests]]
# Optional name for this test suite.
name = "Cat tests"
# Test paths are a list of glob patterns.
paths = [ "cat-test/*.txt" ]
# Command to run on each test file. {} is replaced with the path.
cmd = "cat {}"
# More test suite configurations ...
[[tests]]
```
Run `runt <dir>` to execute all the tests. `<dir>` defaults to the current
directory.
### Options
**Showing diffs**: By default, runt does not show diffs between the new output
and the expect file. Use `--diff` to show the diffs.
**Saving changes**: The `--save` flag overwrites the expect files to save the
updated outputs.
**Suppress specific outputs**: The `--only` flag can be used to focus on only
failing, missing, or correct tests. It composes with the diff and save flags.
### Example
- Runt has a minimal configuration example under cli-tools. The `runt.toml`
file contains all the configuration and explanation for various options.
### Other options
- **[Turnt][]** is a testing framework that allows for more
complex snapshot comparisons. It's particularly powerful when you have
several intermediate files you'd like to compare. `runt` forgoes the
flexibility of turnt for faster execution and built-in output diffing.
- **[insta][]** enables snapshot testing of inline rust programs. Useful when
the testing intrinsic structure of Rust programs. `runt` operators on
arbitrary shell commands which enables testing CLI programs.
- **[jest][]** is a JavaScript snapshot testing framework that allow
formulation of complex expectation queries.
[rust]: https://www.rust-lang.org/tools/install
[turnt]: https://github.com/cucapra/turnt
[insta]: https://docs.rs/insta/0.15.0/insta/
[jest]: https://jestjs.io/