Errors in async code outside of a testsuite results in TypeError

[marconius]

Expected behavior

The actual Error is exposed in the results. e.g:

1) Uncaught error outside test suite

  0 passing (0ms)
  1 failing

  1) Uncaught error outside test suite:
     Uncaught Error: TEST TEST
      at Timeout.setTimeout (test/mocha-init.js:38:9)

Actual behavior

A TypeError is exposed:

  1) Uncaught error outside test suite                                                                                                                                                                                                                                           
/path/to/project/node_modules/mocha-junit-reporter/index.js:106                                                                                                                                                                                                      
    return testsuites[testsuites.length - 1].testsuite;                                                                                                                                                                                                                          
                                             ^                                                                                                                                                                                                                                   
                                                                                                                                                                                                                                                                                 
TypeError: Cannot read property 'testsuite' of undefined                                                                                                                                                                                                                         
    at lastSuite (/path/to/project/node_modules/mocha-junit-reporter/index.js:106:46)                                                                                                                                                                                
    at MochaJUnitReporter.<anonymous> (/path/to/project/node_modules/mocha-junit-reporter/index.js:131:5)                                                                                                                                                            
    at emitTwo (events.js:131:20)                                                                                                                                                                                                                                                
    at Runner.emit (events.js:214:7)                                                                                                                                                                                                                                             
    at Runner.fail (/path/to/project/node_modules/mocha/lib/runner.js:251:8)                                                                                                                                                                                         
    at Runner.uncaught (/path/to/project/node_modules/mocha/lib/runner.js:739:12)                                                                                                                                                                                    
    at process.uncaught (/path/to/project/node_modules/mocha/lib/runner.js:839:10)                                                                                                                                                                                   
    at emitOne (events.js:116:13)                                                                                                                                                                                                                                                
    at process.emit (events.js:211:7)                                                                                                                                                                                                                                            
    at process._fatalException (bootstrap_node.js:378:26)

Information about the Issue

Occurs when an error goes unhandled in async code outside of a testsuite.

Steps to reproduce the behavior

1. Throw an error asynchronously in mocha-init.js

// somewhere in mocha-init.js

setTimeout(() => {
  throw new Error("TEST TEST");
}, 1000);

2. run tests