Add Json rule

Author: Armnajafi

src/Validator.ts

@@ -21,6 +21,7 @@ import { RequiredWithAllRule } from './rules/RequiredWithAllRule';
 import { RequiredWithoutAllRule } from './rules/RequiredWithoutAllRule';
 import { UppercaseRule } from './rules/UppercaseRule';
 import { LowercaseRule } from './rules/LowercaseRule';
+import { JsonRule } from './rules/JsonRule';
 
 
 export class Validator {
@@ -44,7 +45,8 @@ export class Validator {
     required_with_all: new RequiredWithAllRule(),
     required_without_all: new RequiredWithoutAllRule(),
     uppercase: new UppercaseRule(),
-    lowercase: new LowercaseRule()
+    lowercase: new LowercaseRule(),
+    json: new JsonRule()
   };
 
   constructor(private locale: string = 'en') {}

src/locales/en.json

@@ -15,5 +15,6 @@
     "required_with_all": "The {field} field is required when all of {other} are present.",
     "required_without_all": "The {field} field is required when none of {other} are present.",
     "uppercase": "The {field} field must be uppercase.",
-    "lowercase": "The {field} field must be lowercase."
+    "lowercase": "The {field} field must be lowercase.",
+    "json": "The {field} field must be a valid JSON string."
 }

src/locales/fa.json

@@ -9,6 +9,7 @@
     "required_with_all": "فیلد {field} هنگامی که تمام فیلدهای {other} موجود باشند، الزامی است.",
     "required_without_all": "فیلد {field} هنگامی که هیچ یک از فیلدهای {other} موجود نباشند، الزامی است.",
     "uppercase": "فیلد {field} باید با حروف بزرگ باشد.",
-    "lowercase": "فیلد {field} باید با حروف کوچک باشد."
+    "lowercase": "فیلد {field} باید با حروف کوچک باشد.",
+    "json": "فیلد {field} باید یک رشته JSON معتبر باشد."
 }
 

src/rules/JsonRule.ts

@@ -0,0 +1,33 @@
+import { ValidationRule } from './ValidationRule';
+
+export class JsonRule implements ValidationRule {
+  private defaultMessage = '';
+  private customMessage?: string;
+  
+  setDefaultMessage(message: string) {
+    this.defaultMessage = message;
+  }
+  
+  setCustomMessage(message: string) {
+    this.customMessage = message;
+  }
+  
+  validate(value: any, ruleValue: any, field: string, inputs: Record<string, any>): string | null {
+    // Skip validation if value is empty
+    if (value === undefined || value === null || value === '') {
+      return null;
+    }
+    
+    // Convert value to string if it's not already
+    const stringValue = String(value);
+    
+    // Try to parse the string as JSON
+    try {
+      JSON.parse(stringValue);
+      return null; // Valid JSON
+    } catch (e) {
+      const msg = this.customMessage || this.defaultMessage;
+      return msg.replace('{field}', field);
+    }
+  }
+}