How to use

isNull

function

in

lodash

export function onNullSwitch(trigger) {

  return function (node, newValue, oldValue) {

    if (isNull(newValue) === isNull(oldValue))
      return;

    trigger(node, newValue, oldValue);

  };

}

export function parseSelector(selector) {

  if (isNull(selector))
    return new Set();

  if (!isString(selector))
    throw new Error(`Failed to execute 'parseSelector': Parameter 1 is not a string.`);

  if (!selector.match(/^(:[a-z]+([A-Z][a-z]+)*)+$/))
    throw new Error(`Failed to execute 'parseSelector': '${selector}' is not a valid selector.`);

  return new Set(selector.match(/[a-zA-Z]+/g));

}

if (!isNull(child.style.$.zIndex)) {
  subContexts.push(child);
} else if (child.style.$.position.isAbsolutelyPositioned) {

describe('Test the exercise function', () => {
  it('should generate 10 integers', () => {
    expect(s.exercise(isInteger)).to.have.length(10);
  });

  it('should generate 10 booleans', () => {
    expect(s.exercise(isBoolean)).to.have.length(10).to.satisfy(sample => every(sample, ([b]) => isBoolean(b)));
  });

  it('should generate 5 random values from a set', () => {
    s.def('::color', ['Red', 'Blue', 'Dun']);
    expect(s.exercise('::color', 5)).to.have.length(5);
  });

  it('should generate 7 random values from a named spec', () => {
    s.def('::pairs', s.cat(':n', isInteger, ':s', isString));
    expect(s.exercise('::pairs', 7)).to.have.length(7).to.satisfy(sample => every(sample, ([[n, s]]) =>
                                           isInteger(n) && isString(s)));
  });

  it('should generate 10 random values from a spec object', () => {
    expect(s.exercise(s.nilable(isString))).to.have.length(10).to.satisfy(sample => every(sample, ([s]) => isNull(s) || isString(s)));
  });

  it('should throw an exception', () => {
    s.def('::impossible', s.and(isInteger, isString));
    expect(() => s.exercise('::impossible')).to.throw(Error, /sampleFromSpec failed.*/);
  });
});

case 'biginteger':
case 'decimal':
 return !isNull(value) ? toString(value) : '-';
case 'boolean':
 return value !== null ? toString(value) : '-';

const entryLink = (isNull(value) || isUndefined(value) || excludeModel ? 
 '' : 
   onSelectResetsInput={false}
   simpleValue
   value={isNull(value) || isUndefined(value) ? null : {
    value: isFunction(value.toJS) ? value.toJS() : value,
    label: templateObject({ mainField: this.props.relation.displayedAttribute }, isFunction(value.toJS) ? value.toJS() : value).mainField || (isFunction(value.toJS) ? get(value.toJS(), 'id') : get(value, 'id')),

return isNull(value) || isString(value);

/**
 * Converts value to hex representation
 *
 * @public
 * @static
 * @method numberToHex
 * @param {String|Number|BN} value
 * @returns {String}
 */
const numberToHex = value => {
 if (isNull(value) || typeof value === 'undefined') {
  return value;
 }

 // eslint-disable-next-line no-restricted-globals
 if (!isFinite(value) && !isHex(value)) {
  throw new Error(`Given input "${value}" is not a number.`);
 }

 const number = toBN(value);
 const result = number.toString(16);

 return number.lt(new BN(0)) ? `-0x${result.substr(1)}` : `0x${result}`;
}

 isFunction(payloadCreator) || isNull(payloadCreator),
 'Expected payloadCreator to be a function, undefined or null.',
);
let finalPayloadCreator = isNull(payloadCreator)
 ? identity
 : payloadCreator;

if (validationValue === 'json') {
 try {
  if (isObject(value) || isBoolean(value) || isNumber(value) || isArray(value) || isNaN(value) || isNull(value)) {
   value = JSON.parse(JSON.stringify(value));
  } else {

    .to.satisfy(sample => _.every(sample, ([v]) => isNull(v) || isString(v)));
});

if (!isNull(name) && isUndefined(this.grammar.registry.get(name)))
  throw new Error(`Failed to execute 'grammar.use': '${name}' is not a valid grammar name.`);
if (!isNull(name))
  this.grammar.active = this.grammar.registry.get(name);
else
if (!isNull(name) && isUndefined(this.theme.registry.get(name)))
  throw new Error(`Failed to execute 'theme.use': '${name}' is not a valid theme name.`);
if (!isNull(name))
  this.theme.active = this.theme.registry.get(name);
else
let props = isNull(this.theme.active) ? {} : merge({}, ... this.theme.active.settings.filter(({ scope }) => {
  return isNil(scope) || scopes.some(other => scope === other || other.startsWith(`${scope}.`));
}).map(({ settings }) => {

<SortableList
 items={
  isNull(value) || isUndefined(value) || value.size === 0
   ? null
   : value.map(item => {

 isFunction(mapProps) || isNull(mapProps),
 'Expected mapProps to be a function, undefined or null.',
);

if (isNull(this.name))
  return;
if (isNull(this.name))
  return;
return isNull(value) || isString(value);
if (!isNull(value)) {
if (!isNull(this.name)) {