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Type Utilities

A set of utility functions for type checking, conversion, and type guards in TypeScript. Includes primitives/type guards, conversion helpers, and type enforcement. All methods are fully typed.

API Summary​

Interface & Types​

type PrimitiveType = | 'string' | 'number' | 'boolean' | 'symbol' | 'bigint' | 'function' | 'object' | 'array' | 'null' | 'undefined';

Function Documentation & Usage Examples​

isPrimitiveType()​

Checks if a value is of a specific primitive type.

Method Signature:

function isPrimitiveType(value: unknown, type: PrimitiveType): boolean;

Parameters:

  • value: The value to check.
  • type: The primitive type to check against.

Returns:

  • true if the value matches the specified type, otherwise false.

Example:

import { isPrimitiveType } from '@catbee/utils';

isPrimitiveType('hello', 'string'); // true
isPrimitiveType(42, 'number'); // true
isPrimitiveType([], 'array'); // true
isPrimitiveType(null, 'null'); // true

getTypeOf()​

Returns the primitive type of a value as a string.

Method Signature:

getTypeOf(value: unknown): string;

Parameters:

  • value: The value to check.

Returns:

  • The primitive type of the value as a string.

Example:

import { getTypeOf } from '@catbee/utils';

getTypeOf('hello'); // 'string'
getTypeOf(42); // 'number'
getTypeOf([]); // 'array'
getTypeOf(null); // 'null'

isArrayOf()​

Type guard for checking if a value is an array of a specific type.

Method Signature:

function isArrayOf<T>(value: unknown, itemTypeGuard: (item: unknown) => item is T): value is T[];

Parameters:

  • value: The value to check.
  • itemTypeGuard: A type guard function to check each item in the array.

Returns:

  • true if the value is an array and all items pass the type guard, otherwise false.

Example:

import { isArrayOf } from '@catbee/utils';

isArrayOf([1, 2, 3], (item): item is number => typeof item === 'number'); // true
isArrayOf(['a', 'b'], (item): item is string => typeof item === 'string'); // true
isArrayOf([1, '2'], (item): item is number => typeof item === 'number'); // false

toStr()​

Converts a value to a string. Returns a default value if conversion fails.

Method Signature:

function toStr(value: unknown, defaultValue?: string): string;

Parameters:

  • value: The value to convert.
  • defaultValue: The default string to return if conversion fails (optional).

Returns:

  • The string representation of the value, or the default value if conversion fails.

Example:

import { toStr } from '@catbee/utils';

toStr(42); // '42'
toStr({ a: 1 }); // '{"a":1}'
toStr(undefined, 'N/A'); // 'N/A'

toNum()​

Converts a value to a number. Returns a default value if conversion fails.

Method Signature:

function toNum(value: unknown, defaultValue?: number): number;

Parameters:

  • value: The value to convert.
  • defaultValue: The default number to return if conversion fails (optional).

Returns:

  • The number representation of the value, or the default value if conversion fails.

Example:

import { toNum } from '@catbee/utils';

toNum('42'); // 42
toNum('abc', 0); // 0
toNum(undefined, 5); // 5

toBool()​

Converts a value to a boolean. Returns a default value if conversion fails.

Method Signature:

function toBool(value: unknown, defaultValue?: boolean): boolean;

Parameters:

  • value: The value to convert.
  • defaultValue: The default boolean to return if conversion fails (optional).

Returns:

  • The boolean representation of the value, or the default value if conversion fails.

Example:

import { toBool } from '@catbee/utils';

toBool('true'); // true
toBool('no'); // false
toBool(1); // true
toBool(0); // false

ensureType()​

Ensures a value matches the expected type, or provides a default.

Method Signature:

function ensureType<T>(value: unknown, expectedType: string, defaultValue: T): T;

Parameters:

  • value: The value to check.
  • expectedType: The expected type as a string (e.g., 'string', 'number').
  • defaultValue: The default value to return if the type does not match.

Returns:

  • The original value if it matches the expected type, otherwise the default value.

Example:

import { ensureType } from '@catbee/utils';
ensureType(42, 'number', 0); // 42
ensureType('42', 'number', 0); // 0
ensureType(undefined, 'string', 'default'); // 'default'