match spec tightly about which characters to encode, fixes #83, #46

3 files changed, 16 insertions, 21 deletions

diff --git a/src/main/scala/spray/json/JsonPrinter.scala b/src/main/scala/spray/json/JsonPrinter.scala
index bc1e375..d255e03 100644
--- a/src/main/scala/spray/json/JsonPrinter.scala
+++ b/src/main/scala/spray/json/JsonPrinter.scala
@@ -97,21 +97,12 @@ trait JsonPrinter extends (JsValue => String) {
 }
 
 object JsonPrinter {
-  private[this] val mask = new Array[Int](4)
-  private[this] def ascii(c: Char): Int = c & ((c - 127) >> 31) // branchless for `if (c <= 127) c else 0`
-  private[this] def mark(c: Char): Unit = {
-    val b = ascii(c)
-    mask(b >> 5) |= 1 << (b & 0x1F)
-  }
-  private[this] def mark(range: scala.collection.immutable.NumericRange[Char]): Unit = range foreach (mark)
-
-  mark('\u0000' to '\u001f')
-  mark('\u007f')
-  mark('"')
-  mark('\\')
-
-  def requiresEncoding(c: Char): Boolean = {
-    val b = ascii(c)
-    (mask(b >> 5) & (1 << (b & 0x1F))) != 0
-  }
+  def requiresEncoding(c: Char): Boolean =
+    // from RFC 4627
+    // unescaped = %x20-21 / %x23-5B / %x5D-10FFFF
+    c match {
+      case '"'  => true
+      case '\\' => true
+      case c    => c < 0x20
+    }
 }
\ No newline at end of file
diff --git a/src/test/scala/spray/json/CompactPrinterSpec.scala b/src/test/scala/spray/json/CompactPrinterSpec.scala
index 79c0877..6a9560b 100644
--- a/src/test/scala/spray/json/CompactPrinterSpec.scala
+++ b/src/test/scala/spray/json/CompactPrinterSpec.scala
@@ -49,12 +49,16 @@ class CompactPrinterSpec extends Specification {
       CompactPrinter(JsString("xyz")) mustEqual "\"xyz\""
     }
     "properly escape special chars in JsString" in {
-      CompactPrinter(JsString("\"\\\b\f\n\r\t\u12AB")) mustEqual """"\"\\\b\f\n\r\t""" + "\\u12ab\""
-      CompactPrinter(JsString("\u1000")) mustEqual "\"\\u1000\""
-      CompactPrinter(JsString("\u0100")) mustEqual "\"\\u0100\""
+      CompactPrinter(JsString("\"\\\b\f\n\r\t")) mustEqual """"\"\\\b\f\n\r\t""""
+      CompactPrinter(JsString("\u1000")) mustEqual "\"\u1000\""
+      CompactPrinter(JsString("\u0100")) mustEqual "\"\u0100\""
       CompactPrinter(JsString("\u0010")) mustEqual "\"\\u0010\""
       CompactPrinter(JsString("\u0001")) mustEqual "\"\\u0001\""
       CompactPrinter(JsString("\u001e")) mustEqual "\"\\u001e\""
+      // don't escape as it isn't required by the spec
+      CompactPrinter(JsString("\u007f")) mustEqual "\"\u007f\""
+      CompactPrinter(JsString("飞机因此受到损伤")) mustEqual "\"飞机因此受到损伤\""
+      CompactPrinter(JsString("\uD834\uDD1E")) mustEqual "\"\uD834\uDD1E\""
     }
     "properly print a simple JsObject" in (
       CompactPrinter(JsObject("key" -> JsNumber(42), "key2" -> JsString("value")))
diff --git a/src/test/scala/spray/json/PrettyPrinterSpec.scala b/src/test/scala/spray/json/PrettyPrinterSpec.scala
index 8b7bc2b..27137a8 100644
--- a/src/test/scala/spray/json/PrettyPrinterSpec.scala
+++ b/src/test/scala/spray/json/PrettyPrinterSpec.scala
@@ -58,7 +58,7 @@ class PrettyPrinterSpec extends Specification {
            |      "no": 0
            |    }, ["a", "b", null], false]
            |  }
-           |}""".stripMargin.replace("\u00f8", "\\u00f8")
+           |}""".stripMargin
       }
     }
   }