clean_string_validator 1.0.0

A lightweight, dependency-free Dart package that adds fluent String validation extension methods for emails, passwords, URLs, phone numbers, dates, UUIDs, IP addresses, credit cards, and more.

clean_string_validator

A lightweight, dependency-free Dart package that adds fluent String validation through extension methods — no utility classes, no static method calls, just clean, readable code:

"[e-mail]".isValidEmail;       // true
"Password@123".isStrongPassword;     // true
"https://flutter.dev".isValidUrl;    // true
"[phone]".isValidPhone;        // true
"123".isNumeric;                     // true

Features

• ✅ Zero dependencies — pure Dart, works in Flutter, server, and CLI apps
• ✅ Fluent, discoverable API via extension methods
• ✅ Centralized, non-duplicated regex patterns
• ✅ Clear separation between validators and extensions
• ✅ Extensively unit tested
• ✅ Fully documented with dartdoc comments
• ✅ Zero analyzer warnings, lints-compliant
• ✅ Easy to extend with new validators

Installation

Add this to your pubspec.yaml:

dependencies:
  clean_string_validator: ^1.0.0

Then run:

dart pub get

Or, for Flutter projects:

flutter pub get

Usage

Import the single public entry point:

import 'package:clean_string_validator/clean_string_validator.dart';

That's it — every extension method below becomes available on any String.

Supported Validators

Email

Method	Description
.isValidEmail	Checks for a syntactically valid email

"[e-mail]".isValidEmail; // true

Password

Method	Description
.isStrongPassword	At least 8 chars, upper, lower, digit, and special character

"Password@123".isStrongPassword; // true

Phone

Method	Description
.isValidPhone	Validates Pakistani and generic international numbers

"[phone]".isValidPhone; // true
"03001234567".isValidPhone;   // true

URL

Method	Description
.isValidUrl	Validates HTTP/HTTPS URLs

"https://flutter.dev".isValidUrl; // true

Username

Method	Description
.isValidUsername	3-20 chars: letters, numbers, underscores only

"john_doe123".isValidUsername; // true

Numbers

Method	Description
.isNumeric	Parses as any number
.isInteger	Parses as an integer
.isDouble	Parses as a double
.isPositiveNumber	Numeric value greater than zero
.isNegativeNumber	Numeric value less than zero

"123".isNumeric;         // true
"42".isInteger;          // true
"42.5".isDouble;         // true
"10".isPositiveNumber;   // true
"-10".isNegativeNumber;  // true

Date

Method	Description
.isValidDate	Validates real YYYY-MM-DD calendar dates

"2024-05-10".isValidDate; // true
"2024-02-30".isValidDate; // false

JSON

Method	Description
.isJson	Checks for syntactically valid JSON

'{"name":"John"}'.isJson; // true

UUID

Method	Description
.isUUID	Validates UUID versions 1-5

"123e4567-e89b-12d3-a456-426614174000".isUUID; // true

IPv4 / IPv6 / MAC Address

Method	Description
.isIPv4	Validates IPv4 addresses
.isIPv6	Validates IPv6 addresses
.isMacAddress	Validates MAC addresses

"192.168.0.1".isIPv4;             // true
"::1".isIPv6;                     // true
"00:1B:44:11:3A:B7".isMacAddress; // true

Hex Color

Method	Description
.isHexColor	Validates 3 or 6 digit hex colors (# optional)

"#fff".isHexColor;    // true
"#ffffff".isHexColor; // true

Credit Card

Method	Description
.isValidCreditCard	Validates length and Luhn checksum

"4539578763621486".isValidCreditCard; // true

Text Helpers

Method	Description
.isBlank	Empty or whitespace only
.isNotBlank	Has non-whitespace content
.hasText	Alias for .isNotBlank
.isWhitespace	Non-empty and whitespace only
.containsUppercase	Has at least one uppercase letter
.containsLowercase	Has at least one lowercase letter
.containsNumber	Has at least one digit
.containsSpecialCharacter	Has at least one special character
.containsOnlyLetters	All characters are letters
.containsOnlyDigits	All characters are digits
.isAlphabet	Alias for .containsOnlyLetters
.isAlphaNumeric	All characters are letters or digits
.hasMinLength(int)	Length ≥ given value
.hasMaxLength(int)	Length ≤ given value
.hasExactLength(int)	Length equals given value
.isUpperCase	Entirely uppercase
.isLowerCase	Entirely lowercase
.isTitleCase	Every word capitalized (Hello World)

Folder Structure

clean_string_validator/
├── lib/
│   ├── clean_string_validator.dart   # Public API barrel file
│   └── src/
│       ├── extensions/               # Fluent extension methods
│       ├── validators/               # Pure validation logic
│       ├── regex/                    # Centralized regex patterns
│       └── utils/                    # Shared helpers (Luhn, constants, etc.)
├── example/
│   └── main.dart
├── test/
│   └── ...                           # One test file per validator
├── CHANGELOG.md
├── LICENSE
└── pubspec.yaml

Design Principles

• No duplicated regex — every pattern lives in regex_patterns.dart.
• Validators know nothing about extensions — they're plain, testable static methods.
• Extensions only expose clean getters/methods — no business logic.
• This separation makes it trivial to add new validators (email masking, OTP, PIN, slugs, country-specific rules, etc.) without touching existing files.

Contributing

Contributions are welcome! To add a new validator:

1. Add any new regex to lib/src/regex/regex_patterns.dart.
2. Create a validator in lib/src/validators/ with static methods.
3. Create an extension in lib/src/extensions/ that calls the validator.
4. Export the new extension from lib/clean_string_validator.dart.
5. Add tests covering valid, invalid, empty, and boundary cases.

Please run dart analyze and dart test before submitting a pull request.

License

This package is released under the MIT License.