From e17909b1428fda294cab112cfe7bc85ebc9f54ae Mon Sep 17 00:00:00 2001
From: Cristian Maglie <c.maglie@arduino.cc>
Date: Wed, 22 Feb 2023 10:21:56 +0100
Subject: [PATCH 1/2] Added test for #32

---
 discovery_test.go | 32 ++++++++++++++++++++++++--------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/discovery_test.go b/discovery_test.go
index 9dbfe86..dbd6bc0 100644
--- a/discovery_test.go
+++ b/discovery_test.go
@@ -41,13 +41,29 @@ func TestDisc(t *testing.T) {
 
 	require.NoError(t, discovery.Start())
 
-	n, err := stdin.Write([]byte("quit\n"))
-	require.NoError(t, err)
-	require.Greater(t, n, 0)
-	output := [1024]byte{}
-	n, err = stdout.Read(output[:])
-	require.Greater(t, n, 0)
-	require.NoError(t, err)
+	{
+		// Check that discovery is able to handle an "hello" without parameters gracefully
+		// https://github.com/arduino/pluggable-discovery-protocol-handler/issues/32
+		inN, err := stdin.Write([]byte("hello\n"))
+		require.NoError(t, err)
+		require.Greater(t, inN, 0)
+
+		output := [1024]byte{}
+		outN, err := stdout.Read(output[:])
+		require.Greater(t, outN, 0)
+		require.NoError(t, err)
+		require.Equal(t, "{\n  \"eventType\": \"hello\",\n  \"message\": \"Invalid HELLO command\",\n  \"error\": true\n}\n", string(output[:outN]))
+	}
+
+	{
+		inN, err := stdin.Write([]byte("quit\n"))
+		require.NoError(t, err)
+		require.Greater(t, inN, 0)
 
-	require.Equal(t, "{\n  \"eventType\": \"quit\",\n  \"message\": \"OK\"\n}\n", string(output[:n]))
+		output := [1024]byte{}
+		outN, err := stdout.Read(output[:])
+		require.Greater(t, outN, 0)
+		require.NoError(t, err)
+		require.Equal(t, "{\n  \"eventType\": \"quit\",\n  \"message\": \"OK\"\n}\n", string(output[:outN]))
+	}
 }

From 71b0ce2e26dcb23e1683419a498e0edc4c82fedf Mon Sep 17 00:00:00 2001
From: Cristian Maglie <c.maglie@arduino.cc>
Date: Wed, 22 Feb 2023 10:22:20 +0100
Subject: [PATCH 2/2] Fixed 'hello' command handler to gracefully handle empty
 command

Fix #32
---
 discovery.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/discovery.go b/discovery.go
index db9265b..54f064c 100644
--- a/discovery.go
+++ b/discovery.go
@@ -132,7 +132,11 @@ func (d *Server) Run(in io.Reader, out io.Writer) error {
 
 		switch cmd {
 		case "HELLO":
-			d.hello(fullCmd[6:])
+			if len(fullCmd) < 7 {
+				d.hello("")
+			} else {
+				d.hello(fullCmd[6:])
+			}
 		case "START":
 			d.start()
 		case "LIST":