node.js lazy parser

csv.js

const fs = require('fs');

async function* lineSplitter(filepath) {
    const content = fs.createReadStream(filepath, {
        encoding: 'utf8',
    });
    let previous = '';
    for await (const chunk of content) {
        const lines = (previous + chunk).split('\n');
        for (const line of lines.slice(0, lines.length - 1)) {
            yield line;
        }
        previous = lines[lines.length];
    }
    if (previous) {
        yield previous;
    }
}

async function main() {
    const content = lineSplitter('../resources/stop_times.csv');
    for await (const line of content) {
        console.log(line);
    }
}

main().then(() => process.exit(0));

An example of how to use Node.js async generator api (v10.x) to process big chunks of data lazily