message: add test for membership change
diff: @@ -104,6 +104,33 @@ describe('matrix-to', function() {
  // we don't check the 2nd and 3rd servers because that is done by the next test
  });
  + it('should change candidate server when highest power level user leaves the room', function() {
  + const member95 = {
  + userId: "@alice:pl_95",
  + powerLevel: 95,
  + };
  + const room = mockRoom(null, [
  + {
  + userId: "@alice:pl_50",
  + powerLevel: 50,
  + },
  + {
  + userId: "@alice:pl_75",
  + powerLevel: 75,
  + },
  + member95,
  + ]);
  + const creator = new RoomPermaLinkCreator(room);
  + creator.load();
  + expect(creator._serverCandidates[0]).toBe("pl_95");
  + member95.membership = "left";
  + creator.onMembership({}, member95, "join");
  + expect(creator._serverCandidates[0]).toBe("pl_75");
  + member95.membership = "join";
  + creator.onMembership({}, member95, "left");
  + expect(creator._serverCandidates[0]).toBe("pl_95");
  + });
  +
  it('should pick candidate servers based on user population', function() {
  const room = mockRoom(null, [
  {
  