Fix USVString conversion

jsdom · Aug 9, 2015 · 454ce97 · 454ce97
1 parent 595a791
commit 454ce97
Showing 1 changed file with 27 additions and 1 deletion.
diff --git a/lib/index.js b/lib/index.js
@@ -130,7 +130,33 @@ conversions["ByteString"] = function (V, opts) {
 };
 
 conversions["USVString"] = function (V) {
-    return String(V);
+    const S = String(V);
+    const n = S.length;
+    const U = [];
+    for (let i = 0; i < n; ++i) {
+        const c = S.charCodeAt(i);
+        if (c < 0xD800 || c > 0xDFFF) {
+            U.push(String.fromCodePoint(c));
+        } else if (0xDC00 <= c && c <= 0xDFFF) {
+            U.push(String.fromCodePoint(0xFFFD));
+        } else {
+            if (i === n - 1) {
+                U.push(String.fromCodePoint(0xFFFD));
+            } else {
+                const d = S.charCodeAt(i + 1);
+                if (0xDC00 <= d && d <= 0xDFFF) {
+                    const a = c & 0x3FF;
+                    const b = d & 0x3FF;
+                    U.push(String.fromCodePoint((2 << 15) + (2 << 9) * a + b));
+                    ++i;
+                } else {
+                    U.push(String.fromCodePoint(0xFFFD));
+                }
+            }
+        }
+    }
+
+    return U;
 };
 
 conversions["Date"] = function (V, opts) {