Added method for sorted print

This method prints in the same format
as PrettyPrinter but sorts the keys
of each object lexicographically.

The impetus for this change was this
question:
http://stackoverflow.com/questions/31418626/sort-fields-in-rendered-json

In general it is useful to be able to have more deterministic
control over the ordering of output, if diff tools
are to be used.

1 files changed, 50 insertions, 0 deletions

diff --git a/src/test/scala/spray/json/SortedPrinterSpec.scala b/src/test/scala/spray/json/SortedPrinterSpec.scala
new file mode 100644
index 0000000..0ea1045
--- /dev/null
+++ b/src/test/scala/spray/json/SortedPrinterSpec.scala
@@ -0,0 +1,50 @@
+package spray.json
+
+import scala.collection.immutable.ListMap
+import org.specs2.mutable._
+
+class SortedPrinterSpec extends Specification {
+
+  "The SortedPrinter" should {
+    "print a more complicated JsObject nicely aligned with fields sorted" in {
+      val obj = JsonParser {
+        """{
+          |  "Unic\u00f8de" :  "Long string with newline\nescape",
+          |  "Boolean no": false,
+          |  "number": -1.2323424E-5,
+          |  "key with \"quotes\"" : "string",
+          |  "key with spaces": null,
+          |  "simpleKey" : "some value",
+          |    "zero": 0,
+          |  "sub object" : {
+          |    "sub key": 26.5,
+          |    "a": "b",
+          |    "array": [1, 2, { "yes":1, "no":0 }, ["a", "b", null], false]
+          |  },
+          |  "Boolean yes":true
+          |}""".stripMargin
+      }
+      SortedPrinter(obj) mustEqual {
+        """{
+          |  "Boolean no": false,
+          |  "Boolean yes": true,
+          |  "Unic\u00f8de": "Long string with newline\nescape",
+          |  "key with \"quotes\"": "string",
+          |  "key with spaces": null,
+          |  "number": -0.000012323424,
+          |  "simpleKey": "some value",
+          |  "sub object": {
+          |    "a": "b",
+          |    "array": [1, 2, {
+          |      "no": 0,
+          |      "yes": 1
+          |    }, ["a", "b", null], false],
+          |    "sub key": 26.5
+          |  },
+          |  "zero": 0
+          |}""".stripMargin
+      }
+    }
+  }
+
+}