mime-controller/src/validate/index.ts

Helps you find the file type easily.

import {supported_file_types} from '../types/supported-file-types';
import {signatures} from '../signatures';
import {check_start} from './check-start';
import 'syncforeachloop';
import { check_end } from './check-end';
import { check_magic } from './check-magic'

export function validate(data:Buffer,format:supported_file_types){
    
    return new Promise<boolean>(async (resolve, reject) => {

        if (Buffer.isBuffer(data)) {
            var data_hex = data.toString('hex').toUpperCase();
        }else{
            console.error('The value must be of type buffer.');
            return reject(new Error('The value must be of type buffer.'));
        }

        var properties = signatures[format];

        if (properties.magic_numbers) {

            if (properties.magic_numbers.start_with) {
                if (!await check_start(properties.magic_numbers.start_with,data_hex)) {
                    return resolve(false);            
                } 
            }
        
            if (properties.magic_numbers.ends_with) {
                if (!await check_end(properties.magic_numbers.ends_with,data_hex)) {
                    return resolve(false);            
                } 
            }
    
            if (properties.magic_numbers.contain) {
                if (!await check_magic(properties.magic_numbers.contain,data_hex)) {
                    return resolve(false);            
                }  
            }

        }

        if (properties.controller) {
            if(!properties.controller(data.toString('ascii'))){
                return resolve(false);
            };
        }

        return resolve(true);

    });

}