enhance: emit an error when the Auth method is specified but no creds…

… were passed (#35)

cmd/vela-email/plugin.go

@@ -31,6 +31,9 @@ var (
 
 	// ErrorMissingSMTPParam is returned when the plugin is missing a smtp host or port parameter.
 	ErrorMissingSMTPParam = errors.New("missing smtp parameter (host/port)")
+
+	// ErrorAuthSpecifiedButCredentialsMissing is returned when the plugin is missing credentials when auth type was specified.
+	ErrorAuthSpecifiedButCredentialsMissing = errors.New("missing credentials when auth type was specified")
 )
 
 // Plugin represents the configuration loaded for the plugin.
@@ -141,6 +144,10 @@ func (p *Plugin) Validate() error {
 		return ErrorMissingSMTPParam
 	}
 
+	if len(p.Auth) > 0 && !(len(p.SMTPHost.Username) > 0 && len(p.SMTPHost.Password) > 0) {
+		return ErrorAuthSpecifiedButCredentialsMissing
+	}
+
 	// set defaults
 	if len(p.Email.Subject) == 0 {
 		p.Email.Subject = DefaultSubject

cmd/vela-email/plugin_test.go

@@ -76,6 +76,28 @@ func TestValidateSuccess(t *testing.T) {
 				Attachment:    noAttachment,
 			},
 		},
+		{
+			name: "return no errors: auth specified with credentials",
+			parameters: Plugin{
+				Email:         mockEmail,
+				EmailFilename: "",
+				SMTPHost:      mockSMTPHost,
+				Attachment:    noAttachment,
+				Auth:          "LoginAuth",
+			},
+		},
+		{
+			name: "return no errors: auth not specified, credentials absent",
+			parameters: Plugin{
+				Email:         mockEmail,
+				EmailFilename: "",
+				SMTPHost: &SMTPHost{
+					Host: "smtphost.com",
+					Port: "234234",
+				},
+				Attachment: noAttachment,
+			},
+		},
 		{
 			name: "return no errors: multiple To emails",
 			parameters: Plugin{
@@ -279,6 +301,20 @@ func TestValidateErrors(t *testing.T) {
 			},
 			wantErr: ErrorMissingSMTPParam,
 		},
+		{
+			name: "SMTP auth supplied but credentials missing",
+			parameters: Plugin{
+				Auth: "LoginAuth",
+				SMTPHost: &SMTPHost{
+					Host: "smtphost.com",
+					Port: "234234",
+				},
+				Email:         mockEmail,
+				EmailFilename: "",
+				Attachment:    noAttachment,
+			},
+			wantErr: ErrorAuthSpecifiedButCredentialsMissing,
+		},
 	}
 
 	for _, test := range tests {