A quick script to simulate dropping files with a Drag & Drop operation

drop-simulation.js

// drop simulation function
async function runDropSimulation(sources, path, options) {
    const { wait = 1000, shouldRelease = true } = options || {};

    // create the data transfer
    const dataTransfer = new DataTransfer();
    for (const src of sources) {
        const blob = await fetch(src).then((res) => res.blob());
        const file = new File([blob], src.split('/').pop(), { type: blob.type });
        dataTransfer.items.add(file);
    }

    // helper to wait for x milliseconds
    const sleep = (time) =>
        new Promise((resolve) => {
            setTimeout(() => {
                resolve();
            }, time);
        });

    // helper to dispatch drag events
    const dispatchDragEvent = (point, type, props) => {
        document.elementFromPoint(point.x, point.y).dispatchEvent(
            new DragEvent(type, {
                clientX: point.x,
                clientY: point.y,
                bubbles: true,
                ...props,
            })
        );
    };

    // we remember last point so we can fire drop when we're done
    let lastPoint;
    for (const [index, point] of path.entries()) {
        await sleep(wait);
        const type = index === 0 ? 'dragenter' : 'dragover';
        dispatchDragEvent(point, type);
        lastPoint = point;
    }

    // exit if should not drop
    if (!shouldRelease) return;

    // wait at end
    await sleep(wait);

    // fire pointerup on last event
    dispatchDragEvent(lastPoint, 'drop', {
        dataTransfer,
    });
}

// how to use
await runDropSimulation(
    // the files we are dragging and dropping
    [
      './my-package.zip', 
      './my-photo.jpeg'
    ],
    // the drag 'n drop path
    [
        // origin
        {
            x: 0,
            y: 0,
        },
        // move
        {
            x: 100,
            y: 100,
        },
        // drop
        {
            x: 200,
            y: 100,
        },
    ],
    {
        // wait time between coordinates
        wait: 1000,
      
        // should fire drop on last coordinate or hold
        shouldRelease: true,
    }
);