Crate goldentests
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A testing library utilizing golden tests.
Why golden tests?
Golden tests allow you to specify the output of some command within a file and automatically ensure that that output doesn’t change. If it does, goldentests will show an error-diff showing the expected and actual output. This way, whenever the output of something changes a human can see the change and decide if it should be kept or is a bug and should be reverted.
What are golden tests useful for?
Golden tests are especially useful for applications that take a file as input and produce output of some kind. For example: compilers and config-parsers (well, parsers in general) are two such applications that can benefit form automated golden tests. In the case of a config parser, you would be able to provide many config examples as tests and ensure that your parser was able to read the files with the expected stdout/stderr output and exit code.
How do I get started?
Include a test in your program that looks something like this:
use goldentests::{ TestConfig, TestResult };
#[test]
fn run_goldentests() -> TestResult<()> {
// Replace "// " with your language's/parser's comment syntax.
// This tells golden tests to embed its keywords in lines beginning with "// "
let config = TestConfig::new("target/debug/my-binary", "directory/with/tests", "// ")?;
config.run_tests()
}Now you can start adding tests to directory/with/tests and each test should
be automatically found and ran by goldentests whenever you run cargo test.
Here’s a quick example of a test file that uses all of goldentest’s features:
import sys
print("hello!\nfriend!")
print("error!", file=sys.stderr)
sys.exit(3)
# Assuming 'python' is the command passed to TestConfig::new:
# args: -B
# expected exit status: 3
# expected stdout:
# hello!
# friend!
# expected stderr: error!
Re-exports
pub use config::TestConfig;pub use error::TestResult;