diff -r 000000000000 -r 6474c204b198 toolkit/devtools/server/tests/unit/test_forwardingprefix.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/devtools/server/tests/unit/test_forwardingprefix.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,194 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/* Exercise prefix-based forwarding of packets to other transports. */
+
+var gMainConnection, gMainTransport;
+var gSubconnection1, gSubconnection2;
+var gClient;
+
+function run_test()
+{
+  DebuggerServer.init();
+
+  add_test(createMainConnection);
+  add_test(TestNoForwardingYet);
+  add_test(createSubconnection1);
+  add_test(TestForwardPrefix1OnlyRoot);
+  add_test(createSubconnection2);
+  add_test(TestForwardPrefix12OnlyRoot);
+  add_test(TestForwardPrefix12WithActor1);
+  add_test(TestForwardPrefix12WithActor12);
+  run_next_test();
+}
+
+/*
+ * Create a pipe connection, and return an object |{ conn, transport }|,
+ * where |conn| is the new DebuggerServerConnection instance, and
+ * |transport| is the client side of the transport on which it communicates
+ * (that is, packets sent on |transport| go to the new connection, and
+ * |transport|'s hooks receive replies).
+ *
+ * |aPrefix| is optional; if present, it's the prefix (minus the ':') for
+ * actors in the new connection.
+ */
+function newConnection(aPrefix)
+{
+  var conn;
+  DebuggerServer.createRootActor = function (aConn) {
+    conn = aConn;
+    return new DebuggerServer.RootActor(aConn, {});
+  };
+
+  var transport = DebuggerServer.connectPipe(aPrefix);
+
+  return { conn: conn, transport: transport };
+}
+
+/* Create the main connection for these tests. */
+function createMainConnection()
+{
+  ({ conn: gMainConnection, transport: gMainTransport }) = newConnection();
+  gClient = new DebuggerClient(gMainTransport);
+  gClient.connect((aType, aTraits) => run_next_test());
+}
+
+/*
+ * Exchange 'echo' messages with five actors:
+ * - root
+ * - prefix1:root
+ * - prefix1:actor
+ * - prefix2:root
+ * - prefix2:actor
+ *
+ * Expect proper echos from those named in |aReachables|, and 'noSuchActor'
+ * errors from the others. When we've gotten all our replies (errors or
+ * otherwise), call |aCompleted|.
+ *
+ * To avoid deep stacks, we call aCompleted from the next tick.
+ */
+function tryActors(aReachables, aCompleted) {
+  let count = 0;
+
+  let outerActor;
+  for (outerActor of [ 'root',
+                       'prefix1:root', 'prefix1:actor',
+                       'prefix2:root', 'prefix2:actor' ]) {
+    /*
+     * Let each callback capture its own iteration's value; outerActor is
+     * local to the whole loop, not to a single iteration.
+     */
+    let actor = outerActor;
+
+    count++;
+
+    gClient.request({ to: actor, type: 'echo', value: 'tango'}, // phone home
+                    (aResponse) => {
+                      if (aReachables.has(actor))
+                        do_check_matches({ from: actor, type: 'echo', value: 'tango' }, aResponse);
+                      else
+                        do_check_matches({ from: actor, error: 'noSuchActor' }, aResponse);
+
+                      if (--count == 0)
+                        do_execute_soon(aCompleted, "tryActors callback " + aCompleted.name);
+                    });
+  }
+}
+
+/*
+ * With no forwarding established, sending messages to root should work,
+ * but sending messages to prefixed actor names, or anyone else, should get
+ * an error.
+ */
+function TestNoForwardingYet()
+{
+  tryActors(Set(['root']), run_next_test);
+}
+
+/*
+ * Create a new pipe connection which forwards its reply packets to
+ * gMainConnection's client, and to which gMainConnection forwards packets
+ * directed to actors whose names begin with |aPrefix + ':'|, and.
+ *
+ * Return an object { conn, transport }, as for newConnection.
+ */
+function newSubconnection(aPrefix)
+{
+  let { conn, transport } = newConnection(aPrefix);
+  transport.hooks = {
+    onPacket: (aPacket) => gMainConnection.send(aPacket),
+    onClosed: () => {}
+  }
+  gMainConnection.setForwarding(aPrefix, transport);
+
+  return { conn: conn, transport: transport };
+}
+
+/* Create a second root actor, to which we can forward things. */
+function createSubconnection1()
+{
+  let { conn, transport } = newSubconnection('prefix1');
+  gSubconnection1 = conn;
+  transport.ready();
+  gClient.expectReply('prefix1:root', (aReply) => run_next_test());
+}
+
+// Establish forwarding, but don't put any actors in that server.
+function TestForwardPrefix1OnlyRoot()
+{
+  tryActors(Set(['root', 'prefix1:root']), run_next_test);
+}
+
+/* Create a third root actor, to which we can forward things. */
+function createSubconnection2()
+{
+  let { conn, transport } = newSubconnection('prefix2');
+  gSubconnection2 = conn;
+  transport.ready();
+  gClient.expectReply('prefix2:root', (aReply) => run_next_test());
+}
+
+function TestForwardPrefix12OnlyRoot()
+{
+  tryActors(Set(['root', 'prefix1:root', 'prefix2:root']), run_next_test);
+}
+
+// A dumb actor that implements 'echo'.
+//
+// It's okay that both subconnections' actors behave identically, because
+// the reply-sending code attaches the replying actor's name to the packet,
+// so simply matching the 'from' field in the reply ensures that we heard
+// from the right actor.
+function EchoActor(aConnection)
+{
+  this.conn = aConnection;
+}
+EchoActor.prototype.actorPrefix = "EchoActor";
+EchoActor.prototype.onEcho = function (aRequest) {
+  /*
+   * Request packets are frozen. Copy aRequest, so that
+   * DebuggerServerConnection.onPacket can attach a 'from' property.
+   */
+  return JSON.parse(JSON.stringify(aRequest));
+};
+EchoActor.prototype.requestTypes = {
+  "echo": EchoActor.prototype.onEcho
+};
+
+function TestForwardPrefix12WithActor1()
+{
+  let actor = new EchoActor(gSubconnection1)
+  actor.actorID = 'prefix1:actor';
+  gSubconnection1.addActor(actor);
+
+  tryActors(Set(['root', 'prefix1:root', 'prefix1:actor', 'prefix2:root']), run_next_test);
+}
+
+function TestForwardPrefix12WithActor12()
+{
+  let actor = new EchoActor(gSubconnection2)
+  actor.actorID = 'prefix2:actor';
+  gSubconnection2.addActor(actor);
+
+  tryActors(Set(['root', 'prefix1:root', 'prefix1:actor', 'prefix2:root', 'prefix2:actor']), run_next_test);
+}