Test for when the config parameter isn't passed

provisioner/puppet-masterless/provisioner_test.go

@@ -183,6 +183,7 @@ func TestProvisionerPrepare_facterFacts(t *testing.T) {
 func TestProvisionerPrepare_extraArguments(t *testing.T) {
 	config := testConfig()
 
+	// Test with missing parameter
 	delete(config, "extra_arguments")
 	p := new(Provisioner)
 	err := p.Prepare(config)
@@ -190,7 +191,7 @@ func TestProvisionerPrepare_extraArguments(t *testing.T) {
 		t.Fatalf("err: %s", err)
 	}
 
-	// Test with malformed fact
+	// Test with malformed value
 	config["extra_arguments"] = "{{}}"
 	p = new(Provisioner)
 	err = p.Prepare(config)
@@ -198,6 +199,7 @@ func TestProvisionerPrepare_extraArguments(t *testing.T) {
 		t.Fatal("should be an error")
 	}
 
+	// Test with valid values
 	config["extra_arguments"] = []string{
 		"arg",
 	}
@@ -222,6 +224,7 @@ func TestProvisionerProvision_extraArguments(t *testing.T) {
 	}
 	config["extra_arguments"] = extraArguments
 
+	// Test with valid values
 	p := new(Provisioner)
 	err := p.Prepare(config)
 	if err != nil {
@@ -238,4 +241,24 @@ func TestProvisionerProvision_extraArguments(t *testing.T) {
 	if !strings.Contains(comm.StartCmd.Command, expectedArgs) {
 		t.Fatalf("Command %q doesn't contain the expected arguments %q", comm.StartCmd.Command, expectedArgs)
 	}
+
+	// Test with missing parameter
+	delete(config, "extra_arguments")
+
+	p = new(Provisioner)
+	err = p.Prepare(config)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	err = p.Provision(ui, comm)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Check the expected `extra_arguments` position for an empty value
+	splitCommand := strings.Split(comm.StartCmd.Command, " ")
+	if "" == splitCommand[len(splitCommand)-2] {
+		t.Fatalf("Command %q contains an extra-space which may cause arg parsing issues", comm.StartCmd.Command)
+	}
 }