Last active
February 2, 2021 12:10
-
-
Save sudojunior/d303fdb6b3055da0fedd1fab4e8c1414 to your computer and use it in GitHub Desktop.
Literal type validation for JavaScript (function access is not an export by default)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| /** | |
| * @typedef {Object} ValidateOptions | |
| * @prop {boolean?} inverse | |
| * @prop {boolean?} optional | |
| * @prop {boolean?} rest | |
| */ | |
| /** | |
| * @param {string} origin | |
| * @param {[string, any, any[], ValidateOptions][]} args | |
| */ | |
| function validate(origin, args) { | |
| const error = (arg, value, types) => new TypeError(`${arg} (${value}) from ${origin} is not of any type ${types}`); | |
| /** | |
| * @param {any} value | |
| * @param {string} type | |
| */ | |
| const single = (value, type) => { | |
| if (typeof type === 'object') { return value instanceof type; } // type is a class constructor | |
| if (typeof type === 'function') { return type(value); } // type is a function predicate check | |
| return typeof value === type; | |
| }; | |
| const multi = (values, types) => values.reduce((value, vAcc) => | |
| types.reduce((type, tAcc) => single(value, type) || tAcc, false) || vAcc, false); | |
| const check = (value, types, options) => ((options ? options.rest : false) | |
| ? multi(value, types) | |
| : types.reduce((acc, next) => single(value, next) || acc, false)); | |
| const condition = (result, options) => !!result || (options.inverse && !result) || options.optional; | |
| for (const [name, value, types, options] of args) { | |
| [ // self argument validation | |
| ['name', name, ['string']], | |
| ['value', value, ['undefined'], { inverse: true }], | |
| ['types', types, ['string', 'object', 'function'], { rest: true }], | |
| ['options', options, ['object'], { optional: true }], | |
| ].forEach(([n, v, t, opts = {}]) => { | |
| const result = check(v, t, opts); | |
| if (!condition(result, opts)) throw error(n, v, t); | |
| }); | |
| const result = check(value, types, options); | |
| if (!condition(result, options)) | |
| throw error(name, value, types); | |
| } | |
| } |
Author
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
This gist has since been converted into a repository and a module.
Please go there to report issues or suggest features.