To write a test in Rust, create a function and add the #[test] attribute on the line above the test function definition.
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| fn plus(a:i32,b:i32)->i32 {
a+b
}
#[test]
fn plus_test() {
assert_eq!(plus(1, 1), 2);
}
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You can run test codes with cargo test. If the test succeeds, it outputs ok.
If it fails, it outputs FAILED.
When successful
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| C:\Users\admin\Desktop\test1>cargo test
Compiling test1 v0.1.0 (C:\Users\admin\Desktop\test1)
Finished test [unoptimized + debuginfo] target(s) in 0.35s
Running unittests src\main.rs (target\debug\deps\test1-be5d3118bc52cb3a.exe)
running 1 test
test plus_test ... ok
test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
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When failed
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| C:\Users\admin\Desktop\test1>cargo test
Compiling test1 v0.1.0 (C:\Users\admin\Desktop\test1)
Finished test [unoptimized + debuginfo] target(s) in 0.33s
Running unittests src\main.rs (target\debug\deps\test1-be5d3118bc52cb3a.exe)
running 1 test
test plus_test ... FAILED
failures:
---- plus_test stdout ----
thread 'plus_test' panicked at 'assertion failed: `(left == right)`
left: `2`,
right: `3`', src\main.rs:7:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
failures:
plus_test
test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
error: test failed, to rerun pass '--bin test1'
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