Attribute Macro cucumber_codegen::then
source · #[then]
Expand description
Attribute to auto-wire the test to the World
implementer.
There are 3 step-specific attributes:
Example
use cucumber::{given, when, World};
#[derive(Debug, Default, World)]
struct MyWorld;
#[given(regex = r"(\S+) is (\d+)")]
#[when(expr = "{word} is {int}")]
fn test(w: &mut MyWorld, param: String, num: i32) {
assert_eq!(param, "foo");
assert_eq!(num, 0);
}
#[tokio::main]
async fn main() {
MyWorld::run("./tests/features/doctests.feature").await;
}
Attribute arguments
-
#[given(regex = "regex")]
Uses
Regex
for matching the step.Regex
is checked at compile time to have valid syntax. -
#[given(expr = "cucumber-expression")]
Uses Cucumber Expression for matching the step. It’s checked at compile time to have valid syntax.
-
#[given("literal")]
Matches the step with an exact literal only. Doesn’t allow any values capturing to use as function arguments.
Function arguments
- First argument has to be mutable reference to the
World
deriver. - Other argument’s types have to implement
FromStr
or it has to be a slice where the element type also implementsFromStr
. - To use
gherkin::Step
, name the argument asstep
, or mark the argument with a#[step]
attribute.
#[given(regex = r"(\S+) is not (\S+)")]
fn test_step(
w: &mut MyWorld,
#[step] s: &Step,
matches: &[String],
) {
assert_eq!(matches[0], "foo");
assert_eq!(matches[1], "bar");
assert_eq!(s.value, "foo is not bar");
}
Return value
A function may also return a Result
, which Err
is expected
to implement Display
, so returning it will cause the step to
fail.