Remember parameters on registration (#2225)

* Remember parameters for sessions
Cleanup sessions on successfully registering or after a while

* Add flakey test

* Update to use time.AfterFunc, add more tests

* Try to drain the channel, if possible

clientapi/routing/register_test.go

@@ -17,6 +17,7 @@ package routing
 import (
 	"regexp"
 	"testing"
+	"time"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
 	"github.com/matrix-org/dendrite/setup/config"
@@ -140,7 +141,7 @@ func TestFlowCheckingExtraneousIncorrectInput(t *testing.T) {
 func TestEmptyCompletedFlows(t *testing.T) {
 	fakeEmptySessions := newSessionsDict()
 	fakeSessionID := "aRandomSessionIDWhichDoesNotExist"
-	ret := fakeEmptySessions.GetCompletedStages(fakeSessionID)
+	ret := fakeEmptySessions.getCompletedStages(fakeSessionID)
 
 	// check for []
 	if ret == nil || len(ret) != 0 {
@@ -208,3 +209,45 @@ func TestValidationOfApplicationServices(t *testing.T) {
 		t.Errorf("user_id should not have been valid: @_something_else:localhost")
 	}
 }
+
+func TestSessionCleanUp(t *testing.T) {
+	s := newSessionsDict()
+
+	t.Run("session is cleaned up after a while", func(t *testing.T) {
+		t.Parallel()
+		dummySession := "helloWorld"
+		// manually added, as s.addParams() would start the timer with the default timeout
+		s.params[dummySession] = registerRequest{Username: "Testing"}
+		s.startTimer(time.Millisecond, dummySession)
+		time.Sleep(time.Millisecond * 2)
+		if data, ok := s.getParams(dummySession); ok {
+			t.Errorf("expected session to be deleted: %+v", data)
+		}
+	})
+
+	t.Run("session is deleted, once the registration completed", func(t *testing.T) {
+		t.Parallel()
+		dummySession := "helloWorld2"
+		s.startTimer(time.Minute, dummySession)
+		s.deleteSession(dummySession)
+		if data, ok := s.getParams(dummySession); ok {
+			t.Errorf("expected session to be deleted: %+v", data)
+		}
+	})
+
+	t.Run("session timer is restarted after second call", func(t *testing.T) {
+		t.Parallel()
+		dummySession := "helloWorld3"
+		// the following will start a timer with the default timeout of 5min
+		s.addParams(dummySession, registerRequest{Username: "Testing"})
+		s.addCompletedSessionStage(dummySession, authtypes.LoginTypeRecaptcha)
+		s.addCompletedSessionStage(dummySession, authtypes.LoginTypeDummy)
+		s.getCompletedStages(dummySession)
+		// reset the timer with a lower timeout
+		s.startTimer(time.Millisecond, dummySession)
+		time.Sleep(time.Millisecond * 2)
+		if data, ok := s.getParams(dummySession); ok {
+			t.Errorf("expected session to be deleted: %+v", data)
+		}
+	})
+}