function startCameraPreview()

in src/windows/CaptureProxy.js [109:156]
4 lines of code
5 McCabe index (conditional complexity)

    function startCameraPreview (takeCallback, errorCallback, selectCallback, retakeCallback) {
        // try to select appropriate device for capture
        // rear camera is preferred option
        const expectedPanel = Windows.Devices.Enumeration.Panel.back;
        Windows.Devices.Enumeration.DeviceInformation.findAllAsync(Windows.Devices.Enumeration.DeviceClass.videoCapture).done(function (
            devices
        ) {
            if (devices.length > 0) {
                devices.forEach(function (currDev) {
                    if (currDev.enclosureLocation && currDev.enclosureLocation.panel && currDev.enclosureLocation.panel === expectedPanel) {
                        captureSettings.videoDeviceId = currDev.id;
                    }
                });

                capture.initializeAsync(captureSettings).done(
                    function () {
                        // This is necessary since WP8.1 MediaCapture outputs video stream rotated 90 degrees CCW
                        // TODO: This can be not consistent across devices, need additional testing on various devices
                        // msdn.microsoft.com/en-us/library/windows/apps/hh452807.aspx
                        capture.setPreviewRotation(Windows.Media.Capture.VideoRotation.clockwise90Degrees);
                        capturePreview.msZoom = true;

                        capturePreview.src = URL.createObjectURL(capture); // eslint-disable-line no-undef
                        capturePreview.play();

                        previewContainer.style.display = 'block';

                        // Bind events to controls
                        capturePreview.onclick = takeCallback;
                        document.getElementById('takePicture').onclick = takeCallback;
                        document.getElementById('cancelCapture').onclick = function () {
                            errorCallback(CaptureError.CAPTURE_NO_MEDIA_FILES);
                        };
                        document.getElementById('selectPicture').onclick = selectCallback;
                        document.getElementById('retakePicture').onclick = retakeCallback;
                    },
                    function (err) {
                        destroyCameraPreview();
                        errorCallback(CaptureError.CAPTURE_INTERNAL_ERR, err);
                    }
                );
            } else {
                // no appropriate devices found
                destroyCameraPreview();
                errorCallback(CaptureError.CAPTURE_INTERNAL_ERR);
            }
        });
    }