string-guard.md

🛡️ String Guard

Type-safe validation helpers for string values.

The guard module provides a collection of runtime checks for determining whether values are valid strings under different conditions. It helps enforce correctness and type narrowing when working with user input, form data, or external sources.

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Access the strings utility

import atomix from '@nasriya/atomix';

const stringsGuard = atomix.dataTypes.string.guard;

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APIs

API	Description
isAlpha	Checks if a string contains only alphabetic characters
isAlphaNumeric	Checks if a string contains only alphanumeric characters
isBlank	Checks if a string contains only whitespace
isEmpty	Checks if a string is empty
isNotEmpty	Checks if a string is not empty
isString	Checks if a value is a string
isUUID	Checks if a string is a valid UUID (v1, v4, or v5)
isValidString	Checks if a string is not empty after trimming

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API Details

✅ isAlpha

Signature: isAlpha(value: unknown): boolean

Checks if a string contains only alphabetic characters.

stringsGuard.isAlpha('HelloWorld'); // true
stringsGuard.isAlpha('Hello123');   // false

🔡 isAlphaNumeric

Signature: isAlphaNumeric(value: unknown): boolean

Checks if the string contains only letters and numbers.

stringsGuard.isAlphaNumeric('abc123');    // true
stringsGuard.isAlphaNumeric('abc 123');   // false

⚪ isBlank

Signature: isBlank(value: unknown): boolean

Checks if the string contains only whitespace.

stringsGuard.isBlank('   ');
// true

stringsGuard.isBlank('not blank');
// false

📭 isEmpty

Signature: isEmpty(value: unknown): boolean

Checks if the string is empty.

stringsGuard.isEmpty('');
// true

stringsGuard.isEmpty(' ');
// false

✅ isNotEmpty

Signature: isNotEmpty(value: unknown): boolean

Checks if the string is not empty.

stringsGuard.isNotEmpty('text');
// true

stringsGuard.isNotEmpty('');
// false

🧪 isString

Signature: isString(value: unknown): value is string

Checks if the value is a string.

stringsGuard.isString('hello');
// true

stringsGuard.isString(123);
// false

🔍 isUUID

Signature: isUUID(value: unknown, version?: 'v1' | 'v4' | 'v5'): boolean

Checks if the value is a valid UUID.

stringsGuard.isUUID('550e8400-e29b-41d4-a716-446655440000');
// true (v4)

stringsGuard.isUUID('550e8400-e29b-11d4-a716-446655440000', 'v1');
// true

🟩 isValidString

Signature: isValidString(value: unknown): boolean

Checks if the string is non-empty and not just whitespace.

stringsGuard.isValidString('OpenAI');
// true

stringsGuard.isValidString('   ');
// false