add json output support

src/main/scala/net/virtualvoid/sbt/graph/DependencyGraphKeys.scala

@@ -51,6 +51,12 @@ trait DependencyGraphKeys {
     "Prints the ascii graph to the console")
   val asciiTree = TaskKey[String]("dependency-tree-string",
     "Returns a string containing an ascii tree representation of the dependency graph for a project")
+  val jsonTree = TaskKey[String]("dependency-tree-json-string",
+    "Returns a json string dependency tree of non-evicted/used modules")
+  val dependencyJsonTree = TaskKey[File]("dependency-tree-json",
+    "Prints an json tree of all the dependencies to the console")
+  val dependencyJsonFile = SettingKey[File]("dependency-json-file",
+    "The location the json file should be generated at")
   val dependencyTree = TaskKey[Unit]("dependency-tree",
     "Prints an ascii tree of all the dependencies to the console")
   val dependencyList = TaskKey[Unit]("dependency-list",

src/main/scala/net/virtualvoid/sbt/graph/DependencyGraphSettings.scala

@@ -73,6 +73,9 @@ object DependencyGraphSettings {
       }
     },
     asciiTree <<= moduleGraph map rendering.AsciiTree.asciiTree,
+    jsonTree <<= moduleGraph map { (g: ModuleGraph) ⇒ rendering.JsonTree.json(g, { m: Module ⇒ m.isUsed }).toString() },
+    dependencyJsonTree <<= writeToFile(jsonTree, dependencyJsonFile),
+    dependencyJsonFile <<= target / "dependencies-%s.js".format(config.toString),
     dependencyTree <<= print(asciiTree),
     dependencyGraphMLFile <<= target / "dependencies-%s.graphml".format(config.toString),
     dependencyGraphML <<= dependencyGraphMLTask,

src/main/scala/net/virtualvoid/sbt/graph/rendering/JsonTree.scala

@@ -0,0 +1,26 @@
+package net.virtualvoid.sbt.graph.rendering
+
+import net.virtualvoid.sbt.graph.{ Module, ModuleGraph }
+
+import scala.util.parsing.json.{ JSONArray, JSONObject }
+
+object JsonTree {
+
+  def jsonModule(module: Module)(children: Seq[JSONObject]): JSONObject =
+    new JSONObject(Map(
+      "module" -> module.id.name,
+      "group" -> module.id.organisation,
+      "version" -> module.id.version,
+      "evicted" -> module.isEvicted,
+      "errors" -> module.error.getOrElse("None"),
+      "license" -> module.license.getOrElse("Unknown"),
+      "children" -> new JSONArray(children.toList)))
+
+  private def postOrder[T](p: Module ⇒ Boolean)(f: Module ⇒ Seq[T] ⇒ T)(graph: ModuleGraph)(module: Module): T = {
+    val children = graph.dependencyMap.getOrElse(module.id, Seq()).filter(p).map(postOrder(p)(f)(graph))
+    f(module)(children)
+  }
+
+  def json(graph: ModuleGraph, filter: Module ⇒ Boolean): JSONArray =
+    new JSONArray(graph.roots.map(postOrder(filter)(jsonModule)(graph)(_)).toList)
+}