throw new InvalidOperationException ();
}
+ // Characters which have to be escaped:
+ // - Required by JSON Spec: Control characters, '"' and '\\'
+ // - Broken surrogates to make sure the JSON string is valid Unicode
+ // (and can be encoded as UTF8)
+ // - JSON does not require U+2028 and U+2029 to be escaped, but
+ // JavaScript does require this:
+ // http://stackoverflow.com/questions/2965293/javascript-parse-error-on-u2028-unicode-character/9168133#9168133
+ // - '/' also does not have to be escaped, but escaping it when
+ // preceeded by a '<' avoids problems with JSON in HTML <script> tags
+ bool NeedEscape (string src, int i) {
+ char c = src [i];
+ return c < 32 || c == '"' || c == '\\'
+ // Broken lead surrogate
+ || (c >= '\uD800' && c <= '\uDBFF' &&
+ (i == src.Length - 1 || src [i + 1] < '\uDC00' || src [i + 1] > '\uDFFF'))
+ // Broken tail surrogate
+ || (c >= '\uDC00' && c <= '\uDFFF' &&
+ (i == 0 || src [i - 1] < '\uD800' || src [i - 1] > '\uDBFF'))
+ // To produce valid JavaScript
+ || c == '\u2028' || c == '\u2029'
+ // Escape "</" for <script> tags
+ || (c == '/' && i > 0 && src [i - 1] == '<');
+ }
+
internal string EscapeString (string src)
{
if (src == null)
return null;
for (int i = 0; i < src.Length; i++)
- if (src [i] == '"' || src [i] == '\\') {
+ if (NeedEscape (src, i)) {
var sb = new StringBuilder ();
if (i > 0)
sb.Append (src, 0, i);
{
int start = cur;
for (int i = cur; i < src.Length; i++)
- if (src [i] == '"' || src [i] == '\\') {
+ if (NeedEscape (src, i)) {
sb.Append (src, start, i - start);
- sb.Append ('\\');
- sb.Append (src [i]);
+ switch (src [i]) {
+ case '\b': sb.Append ("\\b"); break;
+ case '\f': sb.Append ("\\f"); break;
+ case '\n': sb.Append ("\\n"); break;
+ case '\r': sb.Append ("\\r"); break;
+ case '\t': sb.Append ("\\t"); break;
+ case '\"': sb.Append ("\\\""); break;
+ case '\\': sb.Append ("\\\\"); break;
+ case '/': sb.Append ("\\/"); break;
+ default:
+ sb.Append ("\\u");
+ sb.Append (((int) src [i]).ToString ("x04"));
+ break;
+ }
start = i + 1;
}
sb.Append (src, start, src.Length - start);
Thread.CurrentThread.CurrentCulture = old;
}
}
+
+ // Convert a string to json and parse the string, then compare the result to the original value
+ void CheckString (string str)
+ {
+ var json = new JsonPrimitive (str).ToString ();
+ // Check whether the string is valid Unicode (will throw for broken surrogate pairs)
+ new UTF8Encoding (false, true).GetBytes (json);
+ string jvalue = (string) JsonValue.Parse (json);
+ Assert.AreEqual (str, jvalue);
+ }
+
+ // String handling: http://tools.ietf.org/html/rfc7159#section-7
+ [Test]
+ public void CheckStrings ()
+ {
+ Assert.AreEqual ("\"test\"", new JsonPrimitive ("test").ToString ());
+ // Handling of characters
+ Assert.AreEqual ("\"f\"", new JsonPrimitive ('f').ToString ());
+ Assert.AreEqual ('f', (char) JsonValue.Parse ("\"f\""));
+
+ // Control characters with special escape sequence
+ Assert.AreEqual ("\"\\b\\f\\n\\r\\t\"", new JsonPrimitive ("\b\f\n\r\t").ToString ());
+ // Other characters which must be escaped
+ Assert.AreEqual (@"""\""\\""", new JsonPrimitive ("\"\\").ToString ());
+ // Control characters without special escape sequence
+ for (int i = 0; i < 32; i++)
+ if (i != '\b' && i != '\f' && i != '\n' && i != '\r' && i != '\t')
+ Assert.AreEqual ("\"\\u" + i.ToString ("x04") + "\"", new JsonPrimitive ("" + (char) i).ToString ());
+
+ // JSON does not require U+2028 and U+2029 to be escaped, but
+ // JavaScript does require this:
+ // http://stackoverflow.com/questions/2965293/javascript-parse-error-on-u2028-unicode-character/9168133#9168133
+ Assert.AreEqual ("\"\\u2028\\u2029\"", new JsonPrimitive ("\u2028\u2029").ToString ());
+
+ // '/' also does not have to be escaped, but escaping it when
+ // preceeded by a '<' avoids problems with JSON in HTML <script> tags
+ Assert.AreEqual ("\"<\\/\"", new JsonPrimitive ("</").ToString ());
+ // Don't escape '/' in other cases as this makes the JSON hard to read
+ Assert.AreEqual ("\"/bar\"", new JsonPrimitive ("/bar").ToString ());
+ Assert.AreEqual ("\"foo/bar\"", new JsonPrimitive ("foo/bar").ToString ());
+
+ CheckString ("test\b\f\n\r\t\"\\/</\0x");
+ for (int i = 0; i < 65536; i++)
+ CheckString ("x" + ((char) i));
+
+ // Check broken surrogate pairs
+ CheckString ("\ud800");
+ CheckString ("x\ud800");
+ CheckString ("\udfff\ud800");
+ CheckString ("\ude03\ud912");
+ CheckString ("\uc000\ubfff");
+ CheckString ("\udfffx");
+ // Valid strings should not be escaped:
+ Assert.AreEqual ("\"\ud7ff\"", new JsonPrimitive ("\ud7ff").ToString ());
+ Assert.AreEqual ("\"\ue000\"", new JsonPrimitive ("\ue000").ToString ());
+ Assert.AreEqual ("\"\ud800\udc00\"", new JsonPrimitive ("\ud800\udc00").ToString ());
+ Assert.AreEqual ("\"\ud912\ude03\"", new JsonPrimitive ("\ud912\ude03").ToString ());
+ Assert.AreEqual ("\"\udbff\udfff\"", new JsonPrimitive ("\udbff\udfff").ToString ());
+ }
}
}
projects / mono.git / commitdiff