Test Big5 encode from UTF-8.

src/big5.rs

@@ -371,5 +371,22 @@ mod tests {
         // prefer last
         encode_big5_from_utf16(&[0x2550u16], b"\xF9\xF9");
 
+        // ASCII
+        encode_big5_from_utf8("\u{0061}\u{0062}", b"\x61\x62");
+        // Edge cases
+        encode_big5_from_utf8("\u{9EA6}\u{0061}", b"麦\x61");
+        encode_big5_from_utf8("\u{2626B}\u{0061}", b"𦉫\x61");
+        encode_big5_from_utf8("\u{3000}", b"\xA1\x40");
+        encode_big5_from_utf8("\u{20AC}", b"\xA3\xE1");
+        encode_big5_from_utf8("\u{4E00}", b"\xA4\x40");
+        encode_big5_from_utf8("\u{27607}", b"\xC8\xA4");
+        encode_big5_from_utf8("\u{FFE2}", b"\xC8\xCD");
+        encode_big5_from_utf8("\u{79D4}", b"\xFE\xFE");
+        // Not in index
+        encode_big5_from_utf8("\u{2603}\u{0061}", b"☃\x61");
+        // duplicate low bits
+        encode_big5_from_utf8("\u{203B5}", b"\xFD\x6A");
+        // prefer last
+        encode_big5_from_utf8("\u{2550}", b"\xF9\xF9");
     }
 }

src/testing.rs

@@ -52,7 +52,7 @@ pub fn decode_to_utf8(encoding: &'static Encoding, bytes: &[u8], expect: &str) {
 
 pub fn encode_from_utf8(encoding: &'static Encoding, string: &str, expect: &[u8]) {
     let mut encoder = encoding.new_encoder();
-    let mut dest: Vec<u8> = Vec::with_capacity(10 * string.len()); // 10 is replacement worst case
+    let mut dest: Vec<u8> = Vec::with_capacity(10 * (string.len() + 1)); // 10 is replacement worst case
     let capacity = dest.capacity();
     dest.resize(capacity, 0u8);
     let (complete, read, written, _) = encoder.encode_from_utf8_with_replacement(string,