1 files changed, 25 insertions, 1 deletions
diff --git a/tests/unit/util/str.rs b/tests/unit/util/str.rs
index 63f8fbd8881..c03d8c8086c 100644
--- a/tests/unit/util/str.rs
+++ b/tests/unit/util/str.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use util::str::split_html_space_chars;
+use util::str::{split_html_space_chars, str_join};
 
 
 #[test]
@@ -10,3 +10,27 @@ pub fn split_html_space_chars_whitespace() {
     assert!(split_html_space_chars("").collect::<Vec<_>>().is_empty());
     assert!(split_html_space_chars("\u{0020}\u{0009}\u{000a}\u{000c}\u{000d}").collect::<Vec<_>>().is_empty());
 }
+
+#[test]
+pub fn test_str_join_empty() {
+    let slice = [] as [&str; 0];
+    let actual = str_join(&slice, "-");
+    let expected = "";
+    assert_eq!(actual, expected);
+}
+
+#[test]
+pub fn test_str_join_one() {
+    let slice = ["alpha"];
+    let actual = str_join(&slice, "-");
+    let expected = "alpha";
+    assert_eq!(actual, expected);
+}
+
+#[test]
+pub fn test_str_join_many() {
+    let slice = ["", "alpha", "", "beta", "gamma", ""];
+    let actual = str_join(&slice, "-");
+    let expected = "-alpha--beta-gamma-";
+    assert_eq!(actual, expected);
+}