https://github.com/korbinzhao/aexpr

A safe javascript expression interpreter, support operators / context accessing / property accessing / lodash functions.
https://github.com/korbinzhao/aexpr

expression expression-interpreter expressionengine interpreter javascript nodejs

Last synced: about 1 month ago
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A safe javascript expression interpreter, support operators / context accessing / property accessing / lodash functions.

• Host: GitHub
• URL: https://github.com/korbinzhao/aexpr
• Owner: korbinzhao
• Created: 2022-05-13T08:56:24.000Z (over 2 years ago)
• Default Branch: master
• Last Pushed: 2022-10-28T09:47:17.000Z (about 2 years ago)
• Last Synced: 2024-10-28T12:16:47.671Z (about 2 months ago)
• Topics: expression, expression-interpreter, expressionengine, interpreter, javascript, nodejs
• Language: JavaScript
• Homepage:
• Size: 51.8 KB
• Stars: 20
• Watchers: 3
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: readme.md

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README

        
# Aexpr

Aexpr is safe javascript expression interpreter, support operators / context accessing / property accessing / lodash functions.

# Support

* Data type: number/boolean/string/object/array

* Operators: 

    * Mathematical operators: + - * / 

    * Logic operators: && || > >= < <= === !== 

    * Tenary operator: a ? b : c

* Context access

* Property access

* Functions: 

    * Support all [Lodash](https://lodash.com/docs/4.17.15) functions, but prohibit function type input params to avoid prototype access

# Advantage

* Security assurance

    * Sandbox isolation to avoid prototype accessing using AST

    * Avoid memory leak by prohibit statements like 'while'

* [Lodash](https://lodash.com/docs/4.17.15) functions support

# Usage

```

const interpret = require('aexpr');

// invoke the function

// interpret(codeStr: string, context?: object);

// calculate

interpret('1 + 2 / 4 * 6');

interpret('1 + 2 / (4 * 6)');

// compare

interpret('1 > 2');

interpret('1 < 2');

interpret('1 <= 2');

interpret('2 <= 2');

interpret('2 === 2');

// logic

interpret('1 && 2');

interpret('1 || 0');

// context accessing && property accessing

interpret('a + b / c.d.e', { a: 2, b: 3, c: { d: { e: 5 } } });

// lodash functions

interpret(`_.has(obj, 'a.b')`, { obj: { a: { b: 1, c: 2 } } });

interpret('_.indexOf(arr, 1)', { arr: [1, 2, 3, 4] });

const arr = [

    { 'user': 'barney', 'active': false },

    { 'user': 'fred', 'active': false },

    { 'user': 'pebbles', 'active': true }

];

// not support function type input params to avoid prototype access

expect(interpret.bind(null, `_.findIndex(users, function(o) { return o.user == 'barney'; })`)).toThrow('Parse error');

// support ordinary input params

expect(interpret(`_.findIndex(users, { 'user': 'fred', 'active': false })`, {users: arr})).toBe(1);

```

# license

MIT