Function tmp_env::set_var

pub fn set_var<K: AsRef<OsStr>, V: AsRef<OsStr>>(key: K, value: V) -> CurrentEnv

Sets the environment variable k to the value v for the currently running process. It returns a datastructure to keep the environment variable set. When dropped the environment variable is removed

{
    let _tmp_env = tmp_env::set_var("TEST_TMP_ENV", "myvalue");
    assert_eq!(std::env::var("TEST_TMP_ENV"), Ok(String::from("myvalue")));
}
assert!(std::env::var("TEST_TMP_ENV").is_err());
// Because guard is dropped then the environment variable is also automatically unset
tmp_env::set_var("TEST_TMP_ENV_DROPPED", "myvaluedropped");
assert!(std::env::var("TEST_TMP_ENV_DROPPED").is_err());