serverless-spy
Version:
CDK-based library for writing elegant integration tests on AWS serverless architecture and an additional web console to monitor events in real time.
28 lines (27 loc) • 988 B
JavaScript
import { fromBase64 } from "@smithy/util-base64";
export function blobReader(blob, onChunk, chunkSize = 1024 * 1024) {
return new Promise((resolve, reject) => {
const fileReader = new FileReader();
fileReader.onerror = reject;
fileReader.onabort = reject;
const size = blob.size;
let totalBytesRead = 0;
const read = () => {
if (totalBytesRead >= size) {
resolve();
return;
}
fileReader.readAsDataURL(blob.slice(totalBytesRead, Math.min(size, totalBytesRead + chunkSize)));
};
fileReader.onload = (event) => {
const result = event.target.result;
const dataOffset = result.indexOf(",") + 1;
const data = result.substring(dataOffset);
const decoded = fromBase64(data);
onChunk(decoded);
totalBytesRead += decoded.byteLength;
read();
};
read();
});
}