Warning on missing .create()?
dbr opened this issue · comments
Minor thing, but it can be easy to forget to put the .create() call when creating a builder (something I found particularly when using with_body() with multi-lines strings)
Perhaps the impl Drop could warn about this in some way - e.g
struct Mock {
x: u64,
created: bool,
}
impl Mock {
pub fn new() -> Self {
Self {
x: 10,
created: false,
}
}
pub fn with_x(mut self, x: u64) -> Self {
self.x = x;
self
}
#[must_use]
pub fn create(mut self) -> Mock {
self.created = true;
// ...
self
}
}
impl Drop for Mock {
fn drop(&mut self) {
if !self.created {
eprintln!("Missing call to Mock.create()");
}
}
}
fn main() {
Mock::new().with_x(123).create(); // `warning: unused return value of `Mock::create` that must be used`
let _m = Mock::new().with_x(123); // `Missing call to Mock.create()`
let _m = Mock::new().with_x(123).create(); // Happy
}Additionally, adding the must_use attribute to the return of create() may help people avoid forgetting to assign the mocks to objects as per these docs
@dbr both valid points. care to open a PR? otherwise I'll add it to my list but won't get to it too soon.
Yep shall do!
Is there any chance the Mock API could be split into a separate Builder, so that it's harder to accidentally drop .create() or mix up the mocking and asserting/expecting methods?