Add the append method for the Headers API for the Fetch API

This commit will add the append method and associated helper functions, and introduce any necessary changes for it.

tests/unit/script/headers.rs

@@ -0,0 +1,74 @@
+/* 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 script::dom::bindings::str::ByteString;
+use script::dom::headers;
+
+#[test]
+fn test_normalize_empty_bytestring() {
+    // empty ByteString test
+    let empty_bytestring = ByteString::new(vec![]);
+    let actual = headers::normalize_value(empty_bytestring);
+    let expected = ByteString::new(vec![]);
+    assert_eq!(actual, expected);
+}
+
+#[test]
+fn test_normalize_all_whitespace_bytestring() {
+    // All whitespace test. A horizontal tab, a line feed, a carriage return , and a space
+    let all_whitespace_bytestring = ByteString::new(vec![b'\t', b'\n', b'\r', b' ']);
+    let actual = headers::normalize_value(all_whitespace_bytestring);
+    let expected = ByteString::new(vec![]);
+    assert_eq!(actual, expected);
+}
+
+#[test]
+fn test_normalize_non_empty_no_whitespace_bytestring() {
+    // Non-empty, no whitespace ByteString test
+    let no_whitespace_bytestring = ByteString::new(vec![b'S', b'!']);
+    let actual = headers::normalize_value(no_whitespace_bytestring);
+    let expected = ByteString::new(vec![b'S', b'!']);
+    assert_eq!(actual, expected);
+}
+
+#[test]
+fn test_normalize_non_empty_leading_whitespace_bytestring() {
+    // Non-empty, leading whitespace, no trailing whitespace ByteString test
+    let leading_whitespace_bytestring = ByteString::new(vec![b'\t', b'\n', b' ', b'\r', b'S', b'!']);
+    let actual = headers::normalize_value(leading_whitespace_bytestring);
+    let expected = ByteString::new(vec![b'S', b'!']);
+    assert_eq!(actual, expected);
+}
+
+#[test]
+fn test_normalize_non_empty_no_leading_whitespace_trailing_whitespace_bytestring() {
+    // Non-empty, no leading whitespace, but with trailing whitespace ByteString test
+    let trailing_whitespace_bytestring = ByteString::new(vec![b'S', b'!', b'\t', b'\n', b' ', b'\r']);
+    let actual = headers::normalize_value(trailing_whitespace_bytestring);
+    let expected = ByteString::new(vec![b'S', b'!']);
+    assert_eq!(actual, expected);
+}
+
+#[test]
+fn test_normalize_non_empty_leading_and_trailing_whitespace_bytestring() {
+    // Non-empty, leading whitespace, and trailing whitespace ByteString test
+    let whitespace_sandwich_bytestring =
+        ByteString::new(vec![b'\t', b'\n', b' ', b'\r', b'S', b'!', b'\t', b'\n', b' ', b'\r']);
+    let actual = headers::normalize_value(whitespace_sandwich_bytestring);
+    let expected = ByteString::new(vec![b'S', b'!']);
+    assert_eq!(actual, expected);
+}
+
+#[test]
+fn test_normalize_non_empty_leading_trailing_and_internal_whitespace_bytestring() {
+    // Non-empty, leading whitespace, trailing whitespace,
+    // and internal whitespace ByteString test
+    let whitespace_bigmac_bytestring =
+        ByteString::new(vec![b'\t', b'\n', b' ', b'\r', b'S',
+                             b'\t', b'\n', b' ', b'\r', b'!',
+                             b'\t', b'\n', b' ', b'\r']);
+    let actual = headers::normalize_value(whitespace_bigmac_bytestring);
+    let expected = ByteString::new(vec![b'S', b'\t', b'\n', b' ', b'\r', b'!']);
+    assert_eq!(actual, expected);
+}

tests/unit/script/lib.rs

@@ -12,3 +12,4 @@ extern crate url;
 #[cfg(test)] mod origin;
 #[cfg(all(test, target_pointer_width = "64"))] mod size_of;
 #[cfg(test)] mod textinput;
+#[cfg(test)] mod headers;