Photoshop JavaScript - Arrange layers into a sprite sheet

Layers To Sprite.jsx

// Arrange layers into a sprite sheet.
if (documents.length > 0) {
    var doc = activeDocument;
    var activeLayer = doc.activeLayer; 
    var numLayers = doc.artLayers.length; 
    var spriteX = doc.width;
    var canvasWidth = numLayers * spriteX;
    var canvasHeight = doc.height;

    // Set units in pixels.
    app.preferences.rulerUnits = Units.PIXELS;

    doc.resizeCanvas(canvasWidth, canvasHeight, AnchorPosition.TOPLEFT); 

    // Move the layers around.
    for (i = 0; i < numLayers; i++){
        doc.artLayers[i].visible = 1;
        var movX = spriteX * i;
        doc.artLayers[i].translate(movX, 0);
    }
}