function checkDeviceSupport()

in tools/CCPConnectivityTestTools/scripts/detectRTC.js [693:842]
115 lines of code
43 McCabe index (conditional complexity)

    function checkDeviceSupport(callback) {
        if (!canEnumerate) {
            if (callback) {
                callback();
            }
            return;
        }

        if (!navigator.enumerateDevices && window.MediaStreamTrack && window.MediaStreamTrack.getSources) {
            navigator.enumerateDevices = window.MediaStreamTrack.getSources.bind(window.MediaStreamTrack);
        }

        if (!navigator.enumerateDevices && navigator.enumerateDevices) {
            navigator.enumerateDevices = navigator.enumerateDevices.bind(navigator);
        }

        if (!navigator.enumerateDevices) {
            if (callback) {
                callback();
            }
            return;
        }

        MediaDevices = [];

        audioInputDevices = [];
        audioOutputDevices = [];
        videoInputDevices = [];

        hasMicrophone = false;
        hasSpeakers = false;
        hasWebcam = false;

        isWebsiteHasMicrophonePermissions = false;
        isWebsiteHasWebcamPermissions = false;

        // to prevent duplication
        var alreadyUsedDevices = {};

        navigator.enumerateDevices(function(devices) {
            devices.forEach(function(_device) {
                var device = {};
                for (var d in _device) {
                    try {
                        if (typeof _device[d] !== 'function') {
                            device[d] = _device[d];
                        }
                    } catch (e) {}
                }

                if (alreadyUsedDevices[device.deviceId + device.label + device.kind]) {
                    return;
                }

                // if it is MediaStreamTrack.getSources
                if (device.kind === 'audio') {
                    device.kind = 'audioinput';
                }

                if (device.kind === 'video') {
                    device.kind = 'videoinput';
                }

                if (!device.deviceId) {
                    device.deviceId = device.id;
                }

                if (!device.id) {
                    device.id = device.deviceId;
                }

                if (!device.label) {
                    device.isCustomLabel = true;

                    if (device.kind === 'videoinput') {
                        device.label = 'Camera ' + (videoInputDevices.length + 1);
                    } else if (device.kind === 'audioinput') {
                        device.label = 'Microphone ' + (audioInputDevices.length + 1);
                    } else if (device.kind === 'audiooutput') {
                        device.label = 'Speaker ' + (audioOutputDevices.length + 1);
                    } else {
                        device.label = 'Please invoke getUserMedia once.';
                    }

                    if (typeof DetectRTC !== 'undefined' && DetectRTC.browser.isChrome && DetectRTC.browser.version >= 46 && !/^(https:|chrome-extension:)$/g.test(location.protocol || '')) {
                        if (typeof document !== 'undefined' && typeof document.domain === 'string' && document.domain.search && document.domain.search(/localhost|127.0./g) === -1) {
                            device.label = 'HTTPs is required to get label of this ' + device.kind + ' device.';
                        }
                    }
                } else {
                    // Firefox on Android still returns empty label
                    if (device.kind === 'videoinput' && !isWebsiteHasWebcamPermissions) {
                        isWebsiteHasWebcamPermissions = true;
                    }

                    if (device.kind === 'audioinput' && !isWebsiteHasMicrophonePermissions) {
                        isWebsiteHasMicrophonePermissions = true;
                    }
                }

                if (device.kind === 'audioinput') {
                    hasMicrophone = true;

                    if (audioInputDevices.indexOf(device) === -1) {
                        audioInputDevices.push(device);
                    }
                }

                if (device.kind === 'audiooutput') {
                    hasSpeakers = true;

                    if (audioOutputDevices.indexOf(device) === -1) {
                        audioOutputDevices.push(device);
                    }
                }

                if (device.kind === 'videoinput') {
                    hasWebcam = true;

                    if (videoInputDevices.indexOf(device) === -1) {
                        videoInputDevices.push(device);
                    }
                }

                // there is no 'videoouput' in the spec.
                MediaDevices.push(device);

                alreadyUsedDevices[device.deviceId + device.label + device.kind] = device;
            });

            if (typeof DetectRTC !== 'undefined') {
                // to sync latest outputs
                DetectRTC.MediaDevices = MediaDevices;
                DetectRTC.hasMicrophone = hasMicrophone;
                DetectRTC.hasSpeakers = hasSpeakers;
                DetectRTC.hasWebcam = hasWebcam;

                DetectRTC.isWebsiteHasWebcamPermissions = isWebsiteHasWebcamPermissions;
                DetectRTC.isWebsiteHasMicrophonePermissions = isWebsiteHasMicrophonePermissions;

                DetectRTC.audioInputDevices = audioInputDevices;
                DetectRTC.audioOutputDevices = audioOutputDevices;
                DetectRTC.videoInputDevices = videoInputDevices;
            }

            if (callback) {
                callback();
            }
        });
    }