Feat: More rules

- Implemented nullable rules

package.json

@@ -1,6 +1,6 @@
 {
     "name": "checkmate-ts",
-    "version": "1.0.3",
+    "version": "1.0.4",
     "description": "Checkmate TypeScript - A powerful and flexible object validator written in TypeScript, supporting validation for various data types, nested objects, and arrays. Ensures type safety and reliability in data validation scenarios.",
     "type": "module",
     "exports": {

src/Validator.ts

@@ -36,7 +36,13 @@ class Validator<R extends Rules> {
   }
 
   private validateField(key: string, value: any, rules: Rule[], errors: { [key: string]: string[] }) {
+    const isNullable = rules.includes('nullable')
+
     rules.forEach(rule => {
+      if (isNullable && value == null) {
+        return // If the rule allows `null` values & the value is `null`, skip validating
+      }
+
       if (rule === 'required') {
         validateRequired(key, value, errors)
       } else if (rule === 'string') {

src/types/Rule.ts

@@ -1,4 +1,5 @@
 export type Rule =
+  | 'nullable'
   | 'required'
   | 'string'
   | `min:${number}`

tests/validator.test.ts

@@ -202,4 +202,40 @@ describe('Validator', () => {
     const data = {tags: ['foo', 'test']}
     expect(() => validator.validateObject(data)).toThrow(ValidationError)
   })
+
+  test('should allow null on nullable string value', () => {
+    const validator = Validator.create({
+      'title': ['string', 'nullable'],
+    })
+
+    const data = {title: null}
+    expect(() => validator.validateObject(data)).not.toThrow(ValidationError)
+  })
+
+  test('should allow null on nullable array value', () => {
+    const validator = Validator.create({
+      'tags': ['array', 'nullable'],
+    })
+
+    const data = {tags: null}
+    expect(() => validator.validateObject(data)).not.toThrow(ValidationError)
+  })
+
+  test('should allow null on nullable number value', () => {
+    const validator = Validator.create({
+      'value': ['number', 'nullable'],
+    })
+
+    const data = {value: null}
+    expect(() => validator.validateObject(data)).not.toThrow(ValidationError)
+  })
+
+  test('should allow null on nullable numeric value', () => {
+    const validator = Validator.create({
+      'value': ['numeric', 'nullable'],
+    })
+
+    const data = {value: null}
+    expect(() => validator.validateObject(data)).not.toThrow(ValidationError)
+  })
 })