RUN Test (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:

# 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