Connect Google BigTable and Amazon S3 NDJSON file in our serverless environment

class GoogleBigtableSourceGetRows {
    async init() {
        // TODO: Create your google-bigtable credential
        // More info at https://yepcode.io/docs/integrations/google-bigtable/#credential-configuration
        const googleBigTable = yepcode.integration.googleBigTable(
            "your-google-bigquery-bigtable-name"
        );
        // TODO: Customize your instance and table names
        this.table = await googleBigTable
            .instance("your-instance-name")
            .table("your-table-name");
    }

    async fetch(publish, done) {
        // You can customize get options. eg: get matching keys
        // Look at: https://cloud.google.com/nodejs/docs/reference/bigtable/latest/bigtable/getrowsoptions
        const getRowsOptions = {};
        const [rows] = await this.table.getRows(getRowsOptions);

        for (const rowResponse of rows) {
            const [row] = await rowResponse.get();
            const item = this._mapRowToItem(row);
            await publish(item);
        }
        done();
    }

    _mapRowToItem(row) {
        const columnsAndLastValue = Object.entries(row.data).map(
            ([columnName, columnContent]) => [
                columnName,
                this._getLastColumnValue(columnContent),
            ]
        );
        return Object.fromEntries(columnsAndLastValue);
    }

    _getLastColumnValue(columnContent) {
        // The second [0] is to access the last value
        // You can access previous values by accessing the next
        // elements in the list
        return columnContent[0][0].value;
    }

    async close() {}
}

class AwsS3TargetUploadNdjson {
    async init() {
        // TODO: Create your aws-s3 credential
        // More info at https://yepcode.io/docs/integrations/aws-s3/#credential-configuration
        const awsS3 = yepcode.integration.awsS3("your-aws-s3-credential-name");
        // Transforms the items into a ndjson format
        this.stringifier = ndjson.stringify();
        const targetStream = new PassThrough();
        this.stringifier.pipe(targetStream);
        // TODO: customize the Upload content
        // More info at: https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/interfaces/_aws_sdk_lib_storage.options-1.html
        const upload = new Upload({
            client: awsS3,
            params: {
                Bucket: "your-bucket-name",
                Key: "your-file-name.ndjson",
                Body: targetStream,
            },
        });
        upload.on("httpUploadProgress", (progress) => {
            console.log(`Upload progress`, progress);
        });
        this.uploadPromise = upload.done();
    }

    async consume(item) {
        this.stringifier.write(item);
    }

    async close() {
        try {
            this.stringifier.end();
        } catch (error) {
            console.error(`Error ending stringifier`, error);
        }
        try {
            await this.uploadPromise;
        } catch (error) {
            console.error(`Error ending upload`, error);
        }
    }
}