implement check for existing digit in password

src/main/java/PasswordValidator.java

@@ -4,9 +4,11 @@ public class PasswordValidator {
     int minLength = 6;
     boolean requireUppercase = true;
     boolean requireLowercase = true;
+    boolean requireDigit = true;
 
     private final Pattern uppercasePattern = Pattern.compile("^(?=.*[A-Z]).+$");
     private final Pattern lowercasePattern = Pattern.compile("^(?=.*[a-z]).+$");
+    private final Pattern digitPattern = Pattern.compile("^(?=.*\\d).+$");
 
     public boolean validate(String password) {
         if (password.length() < minLength) {
@@ -15,6 +17,8 @@ public class PasswordValidator {
             return false;
         } else if (requireLowercase && !lowercasePattern.matcher(password).matches()) {
             return false;
+        } else if (requireDigit && !digitPattern.matcher(password).matches()) {
+            return false;
         }
         return true;
     }
@@ -42,4 +46,12 @@ public class PasswordValidator {
     public void setRequireLowercase(boolean requireLowercase) {
         this.requireLowercase = requireLowercase;
     }
+
+    public boolean isRequireDigit() {
+        return requireDigit;
+    }
+
+    public void setRequireDigit(boolean requireDigit) {
+        this.requireDigit = requireDigit;
+    }
 }

src/test/java/PasswordValidatorTest.java

@@ -13,6 +13,7 @@ class PasswordValidatorTest {
         passwordValidator.setMinLength(6);
         passwordValidator.setRequireUppercase(false);
         passwordValidator.setRequireLowercase(false);
+        passwordValidator.setRequireDigit(false);
         assertFalse(passwordValidator.validate("abcde"));
         assertTrue(passwordValidator.validate("abcdef"));
         assertTrue(passwordValidator.validate("abcdefg"));
@@ -20,6 +21,7 @@ class PasswordValidatorTest {
         // test uppercase requirement
         passwordValidator.setRequireUppercase(true);
         passwordValidator.setRequireLowercase(false);
+        passwordValidator.setRequireDigit(false);
         assertFalse(passwordValidator.validate("abcdef"));
         assertTrue(passwordValidator.validate("abCdef"));
         assertTrue(passwordValidator.validate("ABCDEF"));
@@ -27,8 +29,22 @@ class PasswordValidatorTest {
         // test lowercase requirement
         passwordValidator.setRequireUppercase(true);
         passwordValidator.setRequireLowercase(true);
+        passwordValidator.setRequireDigit(false);
         assertFalse(passwordValidator.validate("abcdef"));
         assertTrue(passwordValidator.validate("abCdef"));
         assertFalse(passwordValidator.validate("ABCDEF"));
+
+        // test digits requirement
+        passwordValidator.setRequireUppercase(true);
+        passwordValidator.setRequireLowercase(true);
+        passwordValidator.setRequireDigit(true);
+        assertFalse(passwordValidator.validate("8"));
+        assertFalse(passwordValidator.validate("12345678"));
+        assertFalse(passwordValidator.validate("abcdef"));
+        assertFalse(passwordValidator.validate("abcdef8"));
+        assertFalse(passwordValidator.validate("abCdef"));
+        assertFalse(passwordValidator.validate("ABCDEF"));
+        assertFalse(passwordValidator.validate("ABCDEF8"));
+        assertTrue(passwordValidator.validate("abCDE8F"));
     }
 }