ffc-pay-etl-framework/dist/cjs/validators/uniqueValidator.js

A framework for creating ETL pipelines in node

const { Transform } = require("node:stream");
/**
 *
 * @param {Object} options
 * @param {String} options.message
 * @param {String} options.column
 * @returns Transform
 */
function UniqueValidator(options) {
    let self = this;
    self.column = options.column;
    self.message = options.message ? options.message : "Expected unique value is not unique";
    self.uniqueColumnRows = [];
    function checkIsUnique(data) {
        return self.uniqueColumnRows.indexOf(data) === -1;
    }
    return new Transform({
        readableObjectMode: true,
        writableObjectMode: true,
        decodeStrings: false,
        construct(callback) {
            callback();
        },
        transform(chunk, _, callback) {
            const { _columns } = chunk;
            const colIndex = _columns.indexOf(self.column);
            const uniqueValue = chunk[colIndex];
            if (checkIsUnique(uniqueValue)) {
                self.uniqueColumnRows.push(uniqueValue);
            }
            else {
                chunk.errors.push(`${self.message} ${self.column}`);
            }
            callback(null, chunk);
        }
    });
}
module.exports = {
    UniqueValidator
};