https://github.com/paolosarti/expression2mongoquery

Transform javascript expression to mongo queries
https://github.com/paolosarti/expression2mongoquery

Last synced: 2 months ago
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Transform javascript expression to mongo queries

• Host: GitHub
• URL: https://github.com/paolosarti/expression2mongoquery
• Owner: PaoloSarti
• License: mit
• Created: 2018-10-13T18:00:26.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2023-03-02T10:36:12.000Z (almost 2 years ago)
• Last Synced: 2024-10-09T14:46:37.754Z (3 months ago)
• Language: JavaScript
• Homepage:
• Size: 887 KB
• Stars: 5
• Watchers: 3
• Forks: 0
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# expression2mongoquery

[![Build Status](https://travis-ci.org/PaoloSarti/expression2mongoquery.svg?branch=master)](https://travis-ci.org/PaoloSarti/expression2mongoquery)

[![Coverage Status](https://coveralls.io/repos/github/PaoloSarti/expression2mongoquery/badge.svg?branch=master)](https://coveralls.io/github/PaoloSarti/expression2mongoquery?branch=master)

[![JavaScript Style Guide](https://img.shields.io/badge/code_style-standard-brightgreen.svg)](https://standardjs.com)

## Description

This library compiles javascript expressions to MongoDB queries. In this way, filters can be expressed easily and in a more compact way, without having to write a ton of curly braces ;).

It could be used to specify filters in a plain text configuration.

## Installation

```bash

npm i --save expression2mongoquery

```

## Usage

### Simple Example

```js

const assert = require('assert')

const expressionToMongoQuery = require('expression2mongoquery')()

const query = expressionToMongoQuery('a == "value" && b > 42' )

assert.deepStrictEqual(query, {

  a: 'value',

  b: {

    $gt: 42

  }

})

```

### A More Complex Example

```js

const assert = require('assert')

const expressionToMongoQuery = require('expression2mongoquery')({

  converters: {

    birthDay: d => new Date(d),

  }

})

const query = expressionToMongoQuery('name == "John" && (birthDay > "1990-05-02" || info.id in [1,2,3])')

assert.deepStrictEqual(query, {

  name: 'John',

  $or: [

    {

      birthDay: {

        $gt: new Date('1990-05-02T00:00:00.000Z')

      }

    },

    {

      'info.id': {

        $in: [1, 2, 3]

      }

    }

  ]

})

```

More examples can be found by consulting the test cases.

## Features

This library considers `identifiers` (variables) as document properties, while literal values are treated as values.

It supports:

 - equal and not equal signs for direct equality comparisons

 - equal and not equal to `undefined` translated as `$exists`

 - inequalities such as `>` `<` `>=` and `<=` to `$gt` etc...

 - `in` translated as `$in` for arrays (differently from JavasScript)

 - logical `&&`, `||` and `!` operators to `$or`, `$and`, `$not`

 - arbitrarly nested logical operators expressions

 - parenthesized expressions

 - composite identifiers to query nested documents i.e. `a.b["c"] > 3` becomes `{ 'a.b.c': { $gt: 3 } }`

 - provide your favourite way to parse JavaScript in construction by passing `{ parseExpressionFunction:  }`

 - convert values according to the property name, by providing a `{ converters: { a: d => new Date(d) } }` map

 - regexes: `a == /^c.*/i` becomes `{ a: /^c.*/i }`

## How does it work?

This library parses JavaScript expressions with `acorn` (by default), then navigates the generated `AST` to transform it into `mongo` queries.

The JavaScript code is never evaluated or executed, so there aren't vulnerabilities caused by JavaScript code injection.

## Parser libraries tested

Every test case has passed using all the following parsers:

 - `acorn` (default)

 - `babylon`

 - `esprima`

 - `espree`

Refer to tests to see how you can use the above parsers.