any-eval

Super handy eval of anything.

Supports JS-expression, CommonJS module contents and JSON/JSON5.

Install

$ npm install --save any-eval

Usage

JS-expression

const anyEval = require('any-eval');

anyEval('42 * 42'); // 1764

CommonJS

const anyEval = require('any-eval');
const moduleContents =
`
    const package = require('./package.json');

    module.exports = {
        name: package.name
    };
`;

anyEval(moduleContents, './index.js'); // filename need to provide required info to resolve relative paths inside evaluating code

// ➜ { name: 'any-eval' }

JSON

const anyEval = require('any-eval');
const jsonContents = '{ "name": "any-eval" }';

anyEval(jsonContents, 'my.json'); // filename need to `any-eval` determinate json format by extention

// ➜ { name: 'any-eval' }

JSON5

const anyEval = require('any-eval');
const jsonContents = "{ name: 'any-eval' }";

anyEval(jsonContents, 'my.json5'); // filename need to `any-eval` determinate json format by extention

// ➜ { name: 'any-eval' }

API

anyEval(contents[, filename, context])

contents

Type: string

The JS-expression, CommonJS module contents or JSON/JSON5 contents.

filename

Type: string

The path to file which contents we execute.

The any-eval determinate format by extension. If filename ends with .js, its contents will be evaluating with vm. If filename ends with .json, its contents will be parsing with JSON.parse. If filename ends with .json5, its contents will be parsing with json5.

By default expected JS-expression or CommonJS module contents.

const anyEval = require('any-eval');

anyEval('42 * 42'/* js by default */); // 1764
anyEval('42 * 42', 'my.js'); // 1764
anyEval('{ "name": "any-eval" }', 'my.json'); // '{ name: 'any-eval' }'
anyEval("{ name: 'any-eval' }", 'my.json5');  // '{ name: 'any-eval' }'

To evaluating CommonJS module contents filename is required to resolve relative paths inside evaluating code.

const anyEval = require('any-eval');
const moduleContents =
`
    const package = require('./package.json'); // to resolve this require need to know the path of current module (./index.js)

    module.exports = {
        name: package.name
    };
`;

anyEval(moduleContents, './index.js'); // filename need to provide required info to resolve relative paths inside evaluating code

Internally any-eval will resolve passed relative paths using the place it's called (like require do).

It may spend additional processor's time on it, so better to pass in absolute path.

const fs = require('fs');
const anyEval = require('any-eval');

// For example, current path is "/repos/project/lib/file.js".
const modulePath = '../files/another.js';
const moduleContents = fs.readFileSync(modulePath, 'utf-8');

// '../files/another.js' will be resolved to '/repos/project/files/another.js'
anyEval(moduleContents, modulePath);

context

Type: Object

The object to provide into execute method.

If context is specified, then module contents will be evaluating with vm.runInNewContext.

If context is not specified, then module contents will be evaluating with vm.runInThisContext.

With context you can provide some like-a-global variables into any-eval.

const anyEval = require('any-eval');

const secretKey = '^___^';
const contents = 'module.exports = secretKey;';

anyEval(content, { secretKey }); // '^___^'

Related

• node-eval — eval Node.js contents only (JS-expression, CommonJS modules and JSON).
• node-file-eval — read node.js file and eval it with node-eval.
• file-eval — read any file and eval it with any-eval.