1 files changed, 78 insertions, 0 deletions
diff --git a/library/std/tests/env.rs b/library/std/tests/env.rs
new file mode 100644
index 00000000000..c94fc41178d
--- /dev/null
+++ b/library/std/tests/env.rs
@@ -0,0 +1,78 @@
+use std::env::*;
+use std::ffi::{OsStr, OsString};
+
+use rand::distributions::Alphanumeric;
+use rand::{thread_rng, Rng};
+
+fn make_rand_name() -> OsString {
+    let rng = thread_rng();
+    let n = format!("TEST{}", rng.sample_iter(&Alphanumeric).take(10).collect::<String>());
+    let n = OsString::from(n);
+    assert!(var_os(&n).is_none());
+    n
+}
+
+fn eq(a: Option<OsString>, b: Option<&str>) {
+    assert_eq!(a.as_ref().map(|s| &**s), b.map(OsStr::new).map(|s| &*s));
+}
+
+#[test]
+fn test_set_var() {
+    let n = make_rand_name();
+    set_var(&n, "VALUE");
+    eq(var_os(&n), Some("VALUE"));
+}
+
+#[test]
+fn test_remove_var() {
+    let n = make_rand_name();
+    set_var(&n, "VALUE");
+    remove_var(&n);
+    eq(var_os(&n), None);
+}
+
+#[test]
+fn test_set_var_overwrite() {
+    let n = make_rand_name();
+    set_var(&n, "1");
+    set_var(&n, "2");
+    eq(var_os(&n), Some("2"));
+    set_var(&n, "");
+    eq(var_os(&n), Some(""));
+}
+
+#[test]
+#[cfg_attr(target_os = "emscripten", ignore)]
+fn test_var_big() {
+    let mut s = "".to_string();
+    let mut i = 0;
+    while i < 100 {
+        s.push_str("aaaaaaaaaa");
+        i += 1;
+    }
+    let n = make_rand_name();
+    set_var(&n, &s);
+    eq(var_os(&n), Some(&s));
+}
+
+#[test]
+#[cfg_attr(target_os = "emscripten", ignore)]
+fn test_env_set_get_huge() {
+    let n = make_rand_name();
+    let s = "x".repeat(10000);
+    set_var(&n, &s);
+    eq(var_os(&n), Some(&s));
+    remove_var(&n);
+    eq(var_os(&n), None);
+}
+
+#[test]
+fn test_env_set_var() {
+    let n = make_rand_name();
+
+    let mut e = vars_os();
+    set_var(&n, "VALUE");
+    assert!(!e.any(|(k, v)| { &*k == &*n && &*v == "VALUE" }));
+
+    assert!(vars_os().any(|(k, v)| { &*k == &*n && &*v == "VALUE" }));
+}