Validate custom regular expressions on detector initialization (#1010)

* Validate custom regular expressions on detector initialization

* Add regex name to error message

pkg/custom_detectors/validation.go

@@ -2,6 +2,7 @@ package custom_detectors
 
 import (
 	"fmt"
+	"regexp"
 	"strconv"
 	"strings"
 )
@@ -23,6 +24,11 @@ func ValidateRegex(regex map[string]string) error {
 	if len(regex) == 0 {
 		return fmt.Errorf("no regex")
 	}
+	for name, reg := range regex {
+		if _, err := regexp.Compile(reg); err != nil {
+			return fmt.Errorf("regex '%s': %w", name, err)
+		}
+	}
 	return nil
 }
 

pkg/custom_detectors/validation_test.go

@@ -53,6 +53,13 @@ func TestCustomDetectorsRegexValidation(t *testing.T) {
 			input:   map[string]string{},
 			wantErr: true,
 		},
+		{
+			name: "Test invalid regex",
+			input: map[string]string{
+				"test": "!!?(?:?)[a-zA-Z0-9]{32}",
+			},
+			wantErr: true,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {