Merge pull request #103 from rezakhademix/feature-add-json-validate-rule

feat: IsJSON rule added

ip_test.go

@@ -34,7 +34,7 @@ func Test_IP4(t *testing.T) {
 		{
 			name:        "test empty space string won't pass the ip4 validation rule",
 			field:       "server_ip",
-			value:       "",
+			value:       " ",
 			isPassed:    false,
 			message:     "",
 			expectedMsg: "server_ip should be a valid ipv4",

json.go

@@ -0,0 +1,25 @@
+package govalidator
+
+import "encoding/json"
+
+const (
+	// JSON represents rule name which will be used to find the default error message.
+	JSON = "json"
+	// JSONMsg is the default error message format for fields with JSON validation rule.
+	JSONMsg = "%s should be a valid JSON"
+)
+
+// IsJSON checks if given string is a valid JSON.
+//
+// Example:
+//
+//	v := validator.New()
+//	v.IsJSON("{"menu": {"id": "1", "value": "file"}}", "input", "input should be a valid JSON.")
+//	if v.IsFailed() {
+//		 fmt.Printf("validation errors: %#v\n", v.Errors())
+//	}
+func (v Validator) IsJSON(j, field, msg string) Validator {
+	v.check(json.Valid([]byte(j)), field, v.msg(JSON, msg, field))
+
+	return v
+}

json_test.go

@@ -0,0 +1,78 @@
+package govalidator
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_IsJSON(t *testing.T) {
+	tests := []struct {
+		name        string
+		field       string
+		value       string
+		isPassed    bool
+		message     string
+		expectedMsg string
+	}{
+		{
+			name:        "test {\"menu\": {\"id\": \"1\", \"value\": \"file\"}} is a valid JSON input",
+			field:       "input",
+			value:       "{\"menu\": {\"id\": \"1\", \"value\": \"file\"}}",
+			isPassed:    true,
+			message:     "",
+			expectedMsg: "",
+		},
+		{
+			name:        "test empty string won't pass the JSON validation rule",
+			field:       "input",
+			value:       "",
+			isPassed:    false,
+			message:     "",
+			expectedMsg: "input should be a valid JSON",
+		},
+		{
+			name:        "test empty space string won't pass the JSON validation rule",
+			field:       "input",
+			value:       " ",
+			isPassed:    false,
+			message:     "",
+			expectedMsg: "input should be a valid JSON",
+		},
+		{
+			name:        "test `Reza` won't pass the JSON validation rule",
+			field:       "input",
+			value:       "Reza",
+			isPassed:    false,
+			message:     "",
+			expectedMsg: "input should be a valid JSON",
+		},
+		{
+			name:        "test `{\"example\":2:]}}` won't pass the JSON validation rule",
+			field:       "input",
+			value:       "{\"example\":2:]}}",
+			isPassed:    false,
+			message:     "input should be a valid JSON",
+			expectedMsg: "input should be a valid JSON",
+		},
+	}
+
+	for _, test := range tests {
+		v := New()
+
+		v.IsJSON(test.value, test.field, test.message)
+
+		assert.Equal(t, test.isPassed, v.IsPassed(), test.name)
+
+		if !test.isPassed {
+			assert.Equalf(
+				t,
+				test.expectedMsg,
+				v.Errors()[test.field],
+				"test case %q failed, expected: %s, got: %s",
+				test.expectedMsg,
+				v.Errors()[test.field],
+			)
+		}
+	}
+}

validator.go

@@ -67,6 +67,7 @@ var (
 		Before:    BeforeMsg,
 		After:     AfterMsg,
 		IP4:       IP4Msg,
+		JSON:      JSONMsg,
 	}
 
 	// ErrMethodMessageNotFound is the default message when a method does not have any error message on methodToErrorMessage.