From aa3fe7c6a3842abb303749809366272c4034eb73 Mon Sep 17 00:00:00 2001
From: Sean DuBois <seaduboi@amazon.com>
Date: Mon, 6 Jan 2020 12:40:28 -0800
Subject: [PATCH] Add error message when no pairs

Add error message if pingAllCandidates is called and we
have no candidate pairs. This may help users when debugging.
---
 agent.go     | 6 ++++++
 selection.go | 3 ---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/agent.go b/agent.go
index 075a2c4..f163389 100644
--- a/agent.go
+++ b/agent.go
@@ -654,6 +654,12 @@ func (a *Agent) setSelectedPair(p *candidatePair) {
 }
 
 func (a *Agent) pingAllCandidates() {
+	a.log.Trace("pinging all candidates")
+
+	if len(a.checklist) == 0 {
+		a.log.Warn("pingAllCandidates called with no candidate pairs. Connection is not possible yet.")
+	}
+
 	for _, p := range a.checklist {
 		if p.state == CandidatePairStateWaiting {
 			p.state = CandidatePairStateInProgress
diff --git a/selection.go b/selection.go
index a8e718b..9cbe6c0 100644
--- a/selection.go
+++ b/selection.go
@@ -92,8 +92,6 @@ func (s *controllingSelector) ContactCandidates() {
 			s.nominatePair(p)
 			return
 		}
-
-		s.log.Trace("pinging all candidates")
 		s.agent.pingAllCandidates()
 	}
 }
@@ -215,7 +213,6 @@ func (s *controlledSelector) ContactCandidates() {
 			s.log.Trace("check timeout reached and no valid candidate pair found, marking connection as failed")
 			s.agent.updateConnectionState(ConnectionStateFailed)
 		} else {
-			s.log.Trace("pinging all candidates")
 			s.agent.pingAllCandidates()
 		}
 	}