Sort-Imports fails when 'none' is first sort option

[worldlee78]

tslint and typescript versions

$ tslint --version
5.11.0
$ tsc --version
Version 3.2.1

tslint.json configuration

{
  extends: [
    'tslint-react',
    'tslint-eslint-rules',
    'tslint-config-prettier'
  ],
  defaultSeverity: 'error',
  rulesDirectory: 'tslint-microsoft-contrib',
  rules: {
    'sort-imports': [true, { 'member-syntax-sort-order': ['none', 'all', 'single', 'multiple', 'alias'], 'ignore-case': true }],
  }
};

Typescript code being linted:

import './index.css';
import * as React from 'react';
import App from './App';
import ReactDOM from 'react-dom';

ReactDOM.render(<App />, document.getElementById('root'));

Actual Behavior:
ERROR: src/index.tsx[1, 1]: All imports of type "None" must occur before all imports of type "All"

Expected Behavior:
Should not have any errors

[worldlee78]

If you look at the code, inside the _processMemberSyntaxSortOrder method, the sortOptions does not add the 'none' option to the order array because the if statement of (memberSyntaxTypeMap['none']) evaluates to 0, which is false, and thus is skips adding the option. Changing this to explicitly check for undefined instead of using the "evaluates to false" shortcut should resolve this issue.

It was causing sort-imports to incorrectly state that none must occur before all imports of type all in the above member-syntax-sort-order: ['none', 'all', 'single', 'multiple', 'alias'] even though all none imports were above all imports.