BD local orm

local-orm.js

class Sql {
  repository;

  constructor() {
    this.repository = [];
  }

  createTable(tableName, values) {
    this.repository.push({
      [tableName]: {
        format: [values],
        rows: []
      }
    });

    return this.repository;
  }

  getTable(tableName) {
    const getFreshCopy = () => this.repository.filter(t => {
      return Object.keys(t)[0] === tableName
    });

    const table = getFreshCopy();

    if (table.length < 1) return [];

    return {
      insertRecord: (item) => {
        const Table = table[0][tableName];

        if (this.checkFormat(Table.format, item)) {

          Table.rows.push(item);
          
          return table;
        }
        
        console.log(`ERROR: Could not insert object: ${ JSON.stringify(item) } in table ${ tableName }. Check object types`)
      },

      getRecords: (args) =>  {
        const db = getFreshCopy()[0][tableName].rows;
        const checkProp = (row, prop) => args[prop] ? row[prop] === args[prop] : true

        return db.filter(r => checkProp(r, 'name') && checkProp(r, 'quantity')) || []
      },

      getAllRecords: () => {
        return getFreshCopy()[0][tableName].rows;
      }
    }
  }

  checkFormat(format, values) {
    if (format.length < 1 || values.length < 1) return;

    return Object.keys(values).every(key => typeof values[key] === format[0][key]);
  }
}

const SQL = new Sql();

SQL.createTable('fruit', { name: 'string', quantity: 'number' });
const table = SQL.getTable('fruit');

table.insertRecord({ name: 'Apple', quantity: 20 });
table.insertRecord({ name: 'Orange', quantity: 20 });
table.insertRecord({ name: 'Pineapple', quantity: '20' });
table.insertRecord({ name: 'Grape', quantity: 12 });

console.log('get apples:', table.getRecords({ name: 'Apple', quantity: 20 }));
console.log('get quantity 20:', table.getRecords({ quantity: 20 }));
console.log('get quantity 12:', table.getRecords({ quantity: 12 }));
console.log('get oranges:', table.getRecords({ name: 'Orange' }));
console.log('get bananas:', table.getRecords({ name: 'Bananas' }));

console.log('all records:', table.getAllRecords());