_.js

const sparseMap = {
        'O2': {
            'ExposureAlarm': {
                read: () => _.random(9, 19),
                isExposureAlarm: () => true
            },
            'ExposureWarning': {
                read: () => _.random(24, 27),
                isExposureWarning: () => true
            }
        },
        'COMB': {
            'ExposureAlarm': {
                read: () => _.random(21, 24),
                isExposureAlarm: () => true
            },
            'ExposureWarning': {
                read: () => _.random(14, 18),
                isExposureWarning: () => true
            }
        },
        'H2S': {
            'ExposureAlarm': {
                read: () => _.random(15, 20),
                isExposureAlarm: () => true
            },
            'ExposureWarning': {
                read: () => _.random(12, 15),
                isExposureWarning: () => true
            }
        }
    },
    sparseMapProbe = (gasName, alarmType) => (sparseMap[gasName] || {})[alarmType] || {read: () => 0},
    findByName = (statusConfig, gasName) => statusConfig.sensStatus.find((x) => x.name === gasName);

function Handler(statusConfig, gasName, alarmType) {
    const probe = sparseMapProbe(gasName, alarmType),
        ref = findByName(statusConfig, gasName) || {}; //TODO: make sure the object exists;

    Object.keys(probe).forEach((key) => ref[key] = probe[key]());
    
    return statusConfig;
}