4 releases (2 breaking)
0.3.1 | Sep 29, 2022 |
---|---|
0.3.0 | Sep 15, 2022 |
0.2.0 | Dec 9, 2021 |
0.1.0 | Dec 3, 2021 |
#34 in Testing
28,474 downloads per month
Used in 36 crates
(20 directly)
23KB
372 lines
temp-env
Set environment variables temporarily.
This crate is useful for testing with different environment variables that should not interfere.
This code started as a small test helper written by @fabian-braun and @nbaztec and published by @fabian-braun on StackOverflow. @vmx found it useful and took the time to make it a proper crate.
Examples
temp_env::with_var("MY_ENV_VAR", Some("production"), || {
// Run some code where `MY_ENV_VAR` set to `"production"`.
});
temp_env::with_vars(
vec![
("FIRST_VAR", Some("Hello")),
("SECOND_VAR", Some("World!")),
],
|| {
// Run some code where `FIRST_VAR` is set to `"Hello"` and `SECOND_VAR` is set to
// `"World!"`.
}
);
temp_env::with_vars(
vec![
("FIRST_VAR", Some("Hello")),
("SECOND_VAR", None),
],
|| {
// Run some code where `FIRST_VAR` is set to `"Hello"` and `SECOND_VAR` is unset (even if
// it was set before)
}
);
Starting from version 0.3.0 you can return a value from inside the closure:
let r = temp_env::with_var("MY_ENV_VAR", Some("production"), || {
let envvar = env::var("MY_ENV_VAR").unwrap();
if envvar == "production" {
true
} else {
false
}
});
How does it work?
This crate sets and unsets environment variables for the currently running (Rust) process.
It leverages std::env::set_var
.
The provided functions temp_env::with_*
provide the following features:
- Avoid interference when running concurrently
- Reset previously set env variables back to their original value upon completion, also in case of panic
- Temporarily unsetting env variables
Note that the crate makes use of a singleton mutex to avoid side effects between concurrently running tests. This may impact the degree of concurrency in your test execution.
Features
async_closure
: When enabled you can useasync_with_var()
with async closures. This feature needs at least Rust version 1.64.
License
This project is licensed under either of
- Apache License, Version 2.0, (LICENSE-APACHE) or https://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)
at your option.
Dependencies
~0–5MB
~71K SLoC