key.js

class Key {
    constructor(name, value) {
        this.filters = {
            eq: '=',
            lt: '<',
            lte: '<=',
            gt: '>',
            gte: '>=',
            like: 'LIKE',
            isnull: null
        }
        const parts = name.split('__')
        this.name = parts[0]
        this.value = value
        this.filter = (parts.length > 1 ? parts[1] : 'eq').toLowerCase()
        this.isParameter = this.filter !== 'isnull'
        this.operator = this.filters[this.filter]
        if (this.operator === undefined) {
            this.operator = '='
            this.filter = 'eq'
        }
        if (this.isParameter) {
            this.string = `"${this.name}" ${this.operator} ?`
        } else {
            if (this.value === false) {
                this.string = `"${this.name}" IS NOT NULL`
            } else {
                this.string = `"${this.name}" IS NULL`
            }
        }
    }
}

module.exports = Key