Validate predicates (#236)

* Validate predicates

* Tests

utils/validate.go

@@ -1,6 +1,8 @@
 package utils
 
 import (
+	"bytes"
+	"fmt"
 	"strings"
 
 	"github.com/chargehive/configuration/connectorconfig"
@@ -32,6 +34,12 @@ func Validate(rawJson []byte, version string) map[string]string {
 		return result
 	}
 
+	errs := validatePredicates(o.Selector.Expressions)
+	if errs != "" {
+		result["validation expressions"] = errs
+		return result
+	}
+
 	validate = validator.New()
 	// register custom validators
 	err = validate.RegisterValidation("predicate-key", PredicateKeysValidator)
@@ -99,3 +107,24 @@ func ConnectorLibraryValidator(fl validator.FieldLevel) bool {
 	_, ok := connectorconfig.LibraryRegister[connectorconfig.Library(fl.Field().String())]
 	return ok
 }
+
+func validatePredicates(predicates []selector.Predicate) string {
+
+	buff := bytes.NewBufferString("")
+
+	for _, predicate := range predicates {
+
+		switch predicate.Operator {
+		case selector.PredicateOperatorEqual, selector.PredicateOperatorNotEqual:
+			if len(predicate.Values) != 1 {
+				buff.WriteString(fmt.Sprintf("An %s operator must have exactly one value\n", predicate.Operator))
+			}
+		case selector.PredicateOperatorIn, selector.PredicateOperatorNotIn, selector.PredicateOperatorInLike, selector.PredicateOperatorNotInLike:
+			if len(predicate.Values) <= 1 {
+				buff.WriteString(fmt.Sprintf("An %s operator must have at least two values\n", predicate.Operator))
+			}
+		}
+	}
+
+	return strings.TrimSpace(buff.String())
+}

utils/validate_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 
 	"github.com/chargehive/configuration"
+	"github.com/chargehive/configuration/selector"
 	"github.com/go-playground/assert/v2"
 )
 
@@ -80,6 +81,56 @@ func TestEmptyFields(t *testing.T) {
 	assert.Equal(t, 0, len(errs))
 }
 
+// Test for invalid predicates
+func TestInvalidPredicates(t *testing.T) {
+
+	var tests = []struct {
+		operator selector.PredicateOperator
+		values   []string
+		valid    bool
+	}{
+		{selector.PredicateOperatorEqual, []string{}, false},
+		{selector.PredicateOperatorEqual, []string{"one"}, true},
+		{selector.PredicateOperatorEqual, []string{"one", "two"}, false},
+
+		{selector.PredicateOperatorNotEqual, []string{}, false},
+		{selector.PredicateOperatorNotEqual, []string{"one"}, true},
+		{selector.PredicateOperatorNotEqual, []string{"one", "two"}, false},
+
+		{selector.PredicateOperatorIn, []string{}, false},
+		{selector.PredicateOperatorIn, []string{"one"}, false},
+		{selector.PredicateOperatorIn, []string{"one", "two"}, true},
+
+		{selector.PredicateOperatorNotIn, []string{}, false},
+		{selector.PredicateOperatorNotIn, []string{"one"}, false},
+		{selector.PredicateOperatorNotIn, []string{"one", "two"}, true},
+
+		{selector.PredicateOperatorInLike, []string{}, false},
+		{selector.PredicateOperatorInLike, []string{"one"}, false},
+		{selector.PredicateOperatorInLike, []string{"one", "two"}, true},
+
+		{selector.PredicateOperatorNotInLike, []string{}, false},
+		{selector.PredicateOperatorNotInLike, []string{"one"}, false},
+		{selector.PredicateOperatorNotInLike, []string{"one", "two"}, true},
+	}
+
+	configuration.Initialise()
+
+	for _, v := range tests {
+
+		values, _ := json.Marshal(v.values)
+		rawJson := []byte(`{"kind":"Connector","metadata":{"projectId":"change-me","name":"change-me","displayName":"","description":"","annotations":null,"labels":null,"disabled":false},"specVersion":"v1","selector":{"priority":50,"expressions":[{"key":"charge.label.unsubscribed","operator":"` + string(v.operator) + `","values":` + string(values) + `}]},"spec":{"library":"paysafe","configuration":"eyJtZXJjaGFudFVybCI6ImNoYW5nZS1tZSIsImFjcXVpcmVyIjoiY2hhbmdlLW1lIiwiYWNjb3VudElEIjoiY2hhbmdlLW1lIiwiYXBpVXNlcm5hbWUiOiJjaGFuZ2UtbWUiLCJhcGlQYXNzd29yZCI6ImNoYW5nZS1tZSIsImVudmlyb25tZW50IjoiTU9DSyIsImNvdW50cnkiOiIiLCJjdXJyZW5jeSI6IlVTRCIsInVzZVZhdWx0IjpmYWxzZSwic2luZ2xlVXNlVG9rZW5QYXNzd29yZCI6IiIsInNpbmdsZVVzZVRva2VuVXNlcm5hbWUiOiIifQ=="}}`)
+
+		errs := Validate(rawJson, "v1")
+		if v.valid {
+			assert.Equal(t, 0, len(errs))
+		} else {
+			fmt.Println(errs)
+			assert.Equal(t, 1, len(errs))
+		}
+	}
+}
+
 func PrettyPrint(v interface{}) (err error) {
 	b, err := json.MarshalIndent(v, "", "  ")
 	if err == nil {