Issue description or question

Everything works fine when Wallaby is first started and all the unit tests pass.

However, if you make any change to domainLogicTests.ts (say, press space on an empty line) then the unit test will instantly fail with the following error:

Cannot read property '1' of undefined
	at test/mockInterfaceImpl.ts:14
	at lib/domainLogic.ts:29
	at test/domainLogicTests.ts:38

The unit tests work just fine in Mocha from the command line, even with 'mocha --watch'.

Wallaby.js configuration file

// See: http://wallabyjs.com/docs/config/overview.html
// See: http://wallabyjs.com/docs/intro/config.html
// and  http://wallabyjs.com/docs/config/files.html
module.exports = function (wallaby) {
    return {
        'files': [
            'lib/**/*.ts'
        ],

        'tests': [
            'test/*.ts',
            'test/**/*.ts'
        ],

        'testFramework': 'mocha',

        // http://wallabyjs.com/docs/integration/typescript.html
        compilers: {
            '**/*.ts': wallaby.compilers.typeScript({
                module: 5,  // 1 for CommonJs, 5 for ES6
                target: 2,  // ES6
                typescript: require('typescript')   // use Node typescript version
            })
        },

        // Allow TypeScript to ES6, and then Babel to ES5:
        // From https://github.com/wallabyjs/public/issues/355#issuecomment-159764077
        preprocessors: {
            '**/*.js':
                (file) =>
                    require('babel-core').transform(file.content, { sourceMap: true, presets: ['es2015'] } )
        },

        env: {
            type : 'node',
            runner: 'node'
        },
        
        // I added this after reading through your troubleshooting guide - made no difference
        workers: {
            initial: 1,
            regular: 1,
            recycle: true
        }
    };
};

Code editor or IDE name and version

WebStorm v11
or
Visual Studio Code v0.10.11

OS name and version

Windows 10 - Version 1511 - OS Build 10586.164 (two different computers - but both with similar configuration)