Crate temp_env

This crate is for setting environment variables temporarily.

It is useful for testing with different environment variables that should not interfere.

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)
    }
);

It’s possible the closure returns a value:

let s = temp_env::with_var("INNER_ENV_VAR", Some("inner value"), || {
     std::env::var("INNER_ENV_VAR").unwrap()
});
println!("{}", s);  

Functions

with_var

Sets a single environment variable for the duration of the closure.

with_var_unset

Unsets a single environment variable for the duration of the closure.

with_vars

Sets environment variables for the duration of the closure.

with_vars_unset

Unsets environment variables for the duration of the closure.