Parse error on destructured object parameter with defaults

[bryanburgers]

I have a function defined as follows in my code:

function thing({ one: localOne = 1 } = {}) {
  return localOne;
}

This bit of code is causing Istanbul to fail.

Error message

$ npm run coverage > istanbul-test@0.0.0 coverage /Users/bburgers/projects/tmp > istanbul cover --include-all-sources -i 'lib/**' _mocha 'test/**/*.js' No coverage information was collected, exit without writing coverage information /Users/bburgers/projects/tmp/lib/thing.js:9 function thing({localOne=1:localOne=1}={}){__cov_xOmAt4oxzoE9o4mYWd1f7w.f['1']++;__cov_xOmAt4oxzoE9o4mYWd1f7w.s['2']++;return localOne;}__cov_xOmAt4oxzoE9o4mYWd1f7w.s['3']++;module.exports=thing; ^ SyntaxError: Unexpected token : at Object.exports.runInThisContext (vm.js:76:16) at Module._compile (module.js:542:28) at Object.Module._extensions.(anonymous function) [as .js] (/Users/bburgers/projects/tmp/node_modules/istanbul/lib/hook.js:107:24) at Module.load (module.js:487:32) at tryModuleLoad (module.js:446:12) at Function.Module._load (module.js:438:3) at Module.require (module.js:497:17) at require (internal/module.js:20:19) at Object. (/Users/bburgers/projects/tmp/test/thing.test.js:2:15) at Module._compile (module.js:570:32) at Object.Module._extensions..js (module.js:579:10) at Object.Module._extensions.(anonymous function) [as .js] (/Users/bburgers/projects/tmp/node_modules/istanbul/lib/hook.js:109:37) at Module.load (module.js:487:32) at tryModuleLoad (module.js:446:12) at Function.Module._load (module.js:438:3) at Module.require (module.js:497:17) at require (internal/module.js:20:19) at /Users/bburgers/projects/tmp/node_modules/mocha/lib/mocha.js:222:27 at Array.forEach (native) at Mocha.loadFiles (/Users/bburgers/projects/tmp/node_modules/mocha/lib/mocha.js:219:14) at Mocha.run (/Users/bburgers/projects/tmp/node_modules/mocha/lib/mocha.js:487:10) at Object. (/Users/bburgers/projects/tmp/node_modules/mocha/bin/_mocha:458:18) at Module._compile (module.js:570:32) at Object.Module._extensions..js (module.js:579:10) at Object.Module._extensions.(anonymous function) [as .js] (/Users/bburgers/projects/tmp/node_modules/istanbul/lib/hook.js:109:37) at Module.load (module.js:487:32) at tryModuleLoad (module.js:446:12) at Function.Module._load (module.js:438:3) at Function.Module.runMain (module.js:604:10) at runFn (/Users/bburgers/projects/tmp/node_modules/istanbul/lib/command/common/run-with-cover.js:122:16) at /Users/bburgers/projects/tmp/node_modules/istanbul/lib/command/common/run-with-cover.js:251:17 at /Users/bburgers/projects/tmp/node_modules/istanbul/lib/util/file-matcher.js:68:16 at /Users/bburgers/projects/tmp/node_modules/async/lib/async.js:52:16 at /Users/bburgers/projects/tmp/node_modules/async/lib/async.js:361:13 at /Users/bburgers/projects/tmp/node_modules/async/lib/async.js:52:16 at done (/Users/bburgers/projects/tmp/node_modules/async/lib/async.js:246:17) at /Users/bburgers/projects/tmp/node_modules/async/lib/async.js:44:16 at /Users/bburgers/projects/tmp/node_modules/async/lib/async.js:358:17 at LOOP (fs.js:1758:14) at _combinedTickCallback (internal/process/next_tick.js:67:7) at process._tickCallback (internal/process/next_tick.js:98:9)

This does not seem to be an issue with esprima; this bit of code is correctly parsed by esprima@2.7.x.

It also seems to happen only with the combination of the two es6 features. Both of these bits of code seem to not bother Istanbul:

function thing2({ one: localOne } = {}) {
  return localOne;
}

function thing3({ one = 1 } = {}) {
  return one;
}

I pushed up a repo that replicates this issue: https://github.com/bryanburgers/istanbul-error-reproduction

Run tests with npm test. Run istanbul with npm run coverage.

Running on node 6.8.1.

[darrennolan]

Is this a similar issue? Due to the logger = default to a new instance of the function?

The tests exhaustedly try all combinations of the init function, and then I get 'yellow' for the rest of the method - which seems highly odd as they are indeed run through.

Either that or I'm missing what the feedback here is properly providing.

[airbinder]

Hi, I noticed an error also happened on my codes. The error is:

SyntaxError: Unexpected token :
    at createScript (vm.js:53:10)
    at Object.runInThisContext (vm.js:95:10)
    at Module._compile (module.js:543:28)
    at Object.Module._extensions.(anonymous function) [as .js] (/home/user/.nvm/versions/node/v7.9.0/lib/node_modules/istanbul/lib/hook.js:107:24)
    at Module.load (module.js:488:32)
    at tryModuleLoad (module.js:447:12)
    at Function.Module._load (module.js:439:3)
    at Module.require (module.js:498:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (/home/user/codes/projects/myproject/index.js:9:552)
    at Module._compile (module.js:571:32)
    at Object.Module._extensions.(anonymous function) [as .js] (/home/user/.nvm/versions/node/v7.9.0/lib/node_modules/istanbul/lib/hook.js:107:24)
    at Module.load (module.js:488:32)
    at tryModuleLoad (module.js:447:12)
    at Function.Module._load (module.js:439:3)
    at Module.require (module.js:498:17)

After much commenting and uncommenting the code, I have located the error happened when using destructuring object with default, much like this issue.

Cheers.

[jy95]

Same for me ^^ You can find it there : https://coveralls.io/builds/13109007/source?filename=src%2FTorrentLibrary.js#L190

EDIT : If anyone wants a quick fix , use / istanbul ignore next /

[avocadee]

same for me