@produck/type-error

A utility library for generating and throwing TypeError messages following the
Produck TypeError template format.

Installation

``bash
npm install @produck/type-error
`

API

$3

Generates a formatted error message for type validation failures.

Parameters:
- role - Description of the parameter role (e.g., "args[0]", "options.name")
- expected - Expected type or value description (e.g., "string", "function")

Returns: Formatted error message string

Throws: TypeError if role or expected is not a string

Example:
`javascript
import { ErrorMessage } from '@produck/type-error';

const message = ErrorMessage('args[0]', 'string');
// Returns: Invalid "args[0]", one "string" expected.
`

$3

Throws a TypeError with a formatted message.

Parameters:
- role - Description of the parameter role
- expected - Expected type or value description

Throws: TypeError always with formatted message

Example:
`javascript
import { ThrowTypeError } from '@produck/type-error';

function myFunction(value) {
if (typeof value !== 'string') {
ThrowTypeError('args[0]', 'string');
}
}
`

$3

Creates a reusable assertion function with a custom validation function.

Parameters:
- validate - Function that returns true if value is valid, false otherwise
- defaultExpected - Default "expected" message used in error messages

Returns: An assertion function (value: unknown, role: string, expected?: string) => undefined

Throws: TypeError if validate is not a function or defaultExpected is not
a string

Example:
`javascript
import { AssertionChecker } from '@produck/type-error';

const assertString = AssertionChecker(
(value) => typeof value === 'string',
'string'
);

// Use the assertion
try {
assertString(42, 'args[0]');
} catch (error) {
console.error(error.message);
// TypeError: Invalid "args[0]", one "string" expected.
}

// With custom expected message
try {
assertString(null, 'args[0]', 'non-null string');
} catch (error) {
console.error(error.message);
// TypeError: Invalid "args[0]", one "non-null string" expected.
}
`

Usage Patterns

$3

`javascript
import { ThrowTypeError } from '@produck/type-error';

function processData(data) {
if (typeof data !== 'object' || data === null) {
ThrowTypeError('args[0]', 'object');
}
// ...
}
`

$3

`javascript
import { AssertionChecker } from '@produck/type-error';

const assertNumber = AssertionChecker(
(v) => typeof v === 'number',
'number'
);

const assertArray = AssertionChecker(
(v) => Array.isArray(v),
'array'
);

function calculateSum(numbers) {
assertArray(numbers, 'args[0]');
return numbers.reduce((sum, n) => {
assertNumber(n, 'array element');
return sum + n;
});
}
``

License

MIT

Author

ChaosLee