Polyfill for Blob.stream

Blob.stream-polyfill.js

if (!Blob.prototype.stream) {
    Blob.prototype.stream = function () {
        let offset = 0;
        const chunkSize = 64 * 1024;

        const blob = this;

        return new ReadableStream({
            pull(controller) {
                return new Promise((resolve) => {
                    if (offset < blob.size) {
                        const blobChunk = blob.slice(offset, offset + chunkSize);
                        const reader = new FileReader();
                        reader.onload = (event) => {
                            controller.enqueue(event.currentTarget.result);
                            offset += chunkSize;
                            if (offset >= blob.size) {
                                controller.close();
                            }
                            resolve();
                        };
                        reader.readAsArrayBuffer(blobChunk);
                    }
                });
            },
        });
    };
};