old_contents: 'use strict';
  
  var assert = require('assert');
  var eql = require('deep-eql');
  var extend = require('../');
  
  describe('extend', function() {
    it('should be a function', function() {
      assert(typeof extend === 'function');
    });
  
    it('should have an arity of 1', function() {
      assert(extend.length === 1);
    });
  
    it('should return the first argument', function() {
      var obj = { a: 'a' };
      var obj2 = { b: 'b' };
  
      assert(extend(obj, obj2) === obj);
    });
  
    it('should accept multiple source arguments', function() {
      var a = { a: 'a', aa: 'aa' };
      var b = { b: 'b' };
      var c = { c: 'c', cc: 'cc', ccc: 'ccc' };
      var expected = { a: 'a', aa: 'aa', b: 'b', c: 'c', cc: 'cc', ccc: 'ccc' };
  
      assert(eql(
        extend({}, a, b, c),
        expected
      ));
    });
  
    it('should not copy inherited properties from source objects', function() {
      var parent = { parent: true };
      var child = Object.create(parent);
      child.child = true;
  
      assert(eql(
        extend({}, child),
        { child: true }
      ));
    });
  
    it('should not copy non-enumerable properties from source objects', function() {
      var obj = { a: 'a' };
      Object.defineProperty(obj, 'ignore', { value: true, enumerable: false });
      var expected = { a: 'a', b: 'b' };
  
      assert(eql(
        extend({}, obj, { b: 'b' }),
        expected
      ));
    });
  
    it('should copy falsy values from source objects', function() {
      var obj = { a: 'a', b: null };
      var obj2 = { c: undefined };
      var obj3 = { d: false, e: 0 };
      var expected = { a: 'a', b: null, c: undefined, d: false, e: 0 };
  
      assert(eql(
        extend({}, obj, obj2, obj3),
        expected
      ));
    });
  
    it('should skip `null` and `undefined` values', function() {
      assert(eql(
        extend({ a: 'a' }, null, { b: 'b' }, undefined, { c: 'c' }),
        { a: 'a', b: 'b', c: 'c' }
      ));
    });
  });
  
new_contents: /* globals describe, it */
  
  'use strict';
  
  var assert = require('assert');
  var eql = require('deep-eql');
  var extend = require('../');
  
  describe('extend', function() {
    it('should be a function', function() {
      assert(typeof extend === 'function');
    });
  
    it('should have an arity of 1', function() {
      assert(extend.length === 1);
    });
  
    it('should return the first argument', function() {
      var obj = { a: 'a' };
      var obj2 = { b: 'b' };
  
      assert(extend(obj, obj2) === obj);
    });
  
    it('should accept multiple source arguments', function() {
      var a = { a: 'a', aa: 'aa' };
      var b = { b: 'b' };
      var c = { c: 'c', cc: 'cc', ccc: 'ccc' };
      var expected = { a: 'a', aa: 'aa', b: 'b', c: 'c', cc: 'cc', ccc: 'ccc' };
  
      assert(eql(
        extend({}, a, b, c),
        expected
      ));
    });
  
    it('should not copy inherited properties from source objects', function() {
      var parent = { parent: true };
      var child = Object.create(parent);
      child.child = true;
  
      assert(eql(
        extend({}, child),
        { child: true }
      ));
    });
  
    it('should not copy non-enumerable properties from source objects', function() {
      var obj = { a: 'a' };
      Object.defineProperty(obj, 'ignore', { value: true, enumerable: false });
      var expected = { a: 'a', b: 'b' };
  
      assert(eql(
        extend({}, obj, { b: 'b' }),
        expected
      ));
    });
  
    it('should copy falsy values from source objects', function() {
      var obj = { a: 'a', b: null };
      var obj2 = { c: undefined };
      var obj3 = { d: false, e: 0 };
      var expected = { a: 'a', b: null, c: undefined, d: false, e: 0 };
  
      assert(eql(
        extend({}, obj, obj2, obj3),
        expected
      ));
    });
  
    it('should skip `null` and `undefined` values', function() {
      assert(eql(
        extend({ a: 'a' }, null, { b: 'b' }, undefined, { c: 'c' }),
        { a: 'a', b: 'b', c: 'c' }
      ));
    });
  });
  
subject: Fix linting errors