add tests for configCheck

client.go

@@ -76,6 +76,8 @@ func (c *CloudEvtClient) Alive() bool {
 }
 
 func (c *CloudEvtClient) Pub(event event.Event) error {
+	//TODO: check if connectionType is correct
+
 	if err := c.connectionClient.Send(c.context, event); err != nil {
 		return err
 	}

config.go

@@ -113,12 +113,12 @@ func checkIfProtocolConfigIsSet(protocol string) error {
 func checkIfAllConfigKeysAreSet(protocol string, config interface{}) error {
 	var configMap map[string]interface{}
 	if err := mapstructure.Decode(config, &configMap); err != nil {
-		return fmt.Errorf("could not decode config to map for checking config: %e", err)
+		return fmt.Errorf("could not decode config to map for checking config: %w", err)
 	}
 
 	for configKey := range configMap {
 		if !cloudEvtProvViper.IsSet(protocol + "." + configKey) {
-			return fmt.Errorf("config key %s for protocol %s is not set", configKey, protocol)
+			return fmt.Errorf("%w: missing configKey %s for protocol %s", ErrConfigKeyMissing, configKey, protocol)
 		}
 	}
 	return nil

config_test.go

+package cloudevtprov
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestOptionalConfig(t *testing.T) {
+	// optional config timeoutInSec is missing
+	t.Setenv("CLOUDEVTPROV_PROTOCOL", "nats")
+	t.Setenv("CLOUDEVTPROV_NATS_URL", "http://localhost:4222")
+	t.Setenv("CLOUDEVTPROV_NATS_SUBJECT", "events")
+	t.Setenv("CLOUDEVTPROV_NATS_QUEUEGROUP", "test")
+
+	err := loadConfig()
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+}
+
+func TestMissingConfig(t *testing.T) {
+	// subject config is missing
+	t.Setenv("CLOUDEVTPROV_PROTOCOL", "nats")
+	t.Setenv("CLOUDEVTPROV_NATS_URL", "http://localhost:4222")
+
+	err := loadConfig()
+	if !errors.Is(errors.Unwrap(err), ErrConfigKeyMissing) {
+		t.Errorf("Expected loadConfig to throw an ErrConfigKeyMissing but err is '%v' instead", err)
+	}
+}

error.go

+package cloudevtprov
+
+import "errors"
+
+var ErrConfigKeyMissing = errors.New("required configKey is not set")