Move util::str to style

tests/unit/style/str.rs

@@ -0,0 +1,35 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 style::str::{split_html_space_chars, str_join};
+
+#[test]
+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: [&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);
+}