benderTheCrime / function-parameter-type-validation-decorators

Validate the type of arguments passed to functions with function parameter decorators

Function Parameter Type Validation Decorators

This is a library intended to be used with Babel 6 and babel-runtime or the babel-polyfill (specifically, the babel-plugin-transform-function-parameter-decorators plugin). It works in tandem with function parameter decorators to validate the type of any argument passed to a function.

The decorators themselves will be extended on the window:

function incrementArr(@type.isArray arr) {
    return arr.map(v => v + 1);
}

function typesafeToFixed(@type.isNumber num, places = 2) {
    return num.toFixed(places);
}

This will be transpiled to:

function incrementArr(_arr) {
    var arr = window.type.isArray(_arr);

    return arr.map(v => v + 1);
}

function typesafeToFixed(num, places = 2) {
    var num = window.type.isNumber(_num);

    return num.toFixed(places);
}

The decorator library can also be imported:

import type from 'function-parameter-type-validation-decorators';

function typesafeToLowerCase(@type.isString str) {
    return str.toLowerCase();
}

Which will in turn be transpiled to:

import type from 'function-parameter-type-validation-decorators';

function typesafeToLowerCase(_str) {
    var str = window.type.isString(_str);

    return str.toLowerCase();
}

NOTE:

This package depends on babel-plugin-transform-decorators-legacy and babel-plugin-transform-function-parameter-decorators

Installation & Usage

npm install babel-plugin-transform-decorators-legacy babel-plugin-transform-function-parameter-decorators

Add the following line to your .babelrc file:

    {
        "plugins": [
            "transform-decorators-legacy",
            "transform-function-parameter-decorators"
        ]
    }

and then either use the library similar to the window or the import example above.

License

MIT (c) 2016