Expression Processor

Expression Processor - like its name - is an evaluator (or filter) for an input string. It can parse a string of condition and return true or false depend on key value of the choosen user in the database.

Installation

npm i expression-processor or yarn add expression-processor

Testing

EP provides some sample cases to be run with jest. For testing, please install jest by npm i jest --save-dev or yarn add jest --dev and then npm test or yarn test.

Usage

1. Write down a condition to check (with parentheses). For example, we want to check the type of the phone, the OS and email suffix: (deviceName == iPhone && phoneOs == IOS && email <matches-regex> @yahoo.com)
2. Import the suitable user info
3. Execute!!!

Example

Considered the mentioned condition. This is how we use it:

const Run = require("./index");

const condition =
  "(deviceName == iPhone && phoneOs == iOS && email <matches-regex> @yahoo.com)";
const userInfo = {
  deviceName: "iPhone",
  phoneOs: "iOS",
  email: "package_testing@gmail.com",
};

console.log(Run(userInfo, condition)); // return false

Supported operators/filters

Operator/Filter	Description
||	OR
&&	AND
!	NOT
()	Parentheses
==	EQUAL_TO
!=	NOT_EQUAL_TO
<	LESS_THAN
<=	LESS_THAN_OR_EQUAL_TO
>	GREATER_THAN
>=	GREATER_THAN_OR_EQUAL_TO
<contains>	CONTAINS:
<array-contains>	ARRAY_CONTAINS
<in>	IN
<begins-with>	BEGINS_WITH
<ends-with>	ENDS_WITH
<matches-regex>	MATCHES_REGEX

tags: expression, boolean, condition