fast-csv
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[FEATURE] allow async event handler functions
Is your feature request related to a problem? Please describe. Using async event handlers. Most of my code uses sync function and need to be called with await.
Describe the solution you'd like If an event handler returns a promise, wait on it.
Describe alternatives you've considered Calling async functions from sync code, ...
Any update on this @doug-martin or @dustinsmith1024 - seems like an easy addition but something that would help using standard await/async construncts in modern js. Thanks a lot. Or maybe not that easy because you're not using async functions where you'd need to await event handlers?
@andrisi You can pause the stream while waiting for async operations, like this:
const csvStream = fs.createReadStream('file.csv')
.pipe(csv.parse({ headers: true }))
.on('data', async (row) => {
try {
csvStream.pause();
await doSomethingAsync(row);
} finally {
csvStream.resume();
}
})
.on('end', () => {
});
Thanks @pigpudle good workaround, will use it! Handling async event handlers properly on the other hand - with all events -would be cleaner and in line with what you'd expect when you add an async event handler. It's easy to detect that the result of the event handler function is a promise. Or it's handled outside of your code? I got to learn more about streams...