Weird error message when calling yield from a standard function

[babel-bot]

Issue originally reported by @msageryd in babel/babylon#530

I made the mistake of calling yield from a non-generator function. Actually an anonymous function. I would probably have understood my mistake sooner if I'd got a better error message.

It would be great with a better error message so the next generator-newbie doesn't have to struggle as much :)

I got "SyntaxError: yield is a reserved word".

Here is the code that got me the error:

function* saveUnsavedJournalItemsToServer() {
  const journalItemsToSave = yield select(selectCompletedUnsavedJournalItems);
  journalItemsToSave.map(journalItem => {
    yield fork(saveJournalItemToServer, journalItem);
  }); 
}

Here is the complete output.

journalSagas.js: SyntaxError: yield is a reserved word (177:4)
  175 |
  176 |   journalItemsToSave.map(journalItem => {
> 177 |     yield fork(saveJournalItemToServer, journalItem);
      |     ^
  178 |   });
  179 | }
  180 |

[babel-bot]

Comment originally made by @hzoo

This is a similar issue to babel/babylon#113 (await in a non async function)

[xtuc]

Is this still the case or can we close it?

[msageryd]

To me it's not an issue, since I've learned my lesson. I can't try this out right now. The "issue" is just a heads-up, go ahead and close it if you don't want it in open issues.