Quick question, I create this File object, write content to disk using it, and then return it from inside an async function like so:

...
File file = await makeFileObject(filename);
return await file.writeAsString(content); 
// fyi writeAsString returns Future<File>

but I then I refactored it using the .. notation, and it says it doesn't need the await after return

That's weird. Does .. await the write?

Am I returning the File object before the write occurs or the File object returned by writeAsString?

...
return (await makeFileObject(filename))
    ..writeAsString(content);

Is the refactor functionally equivalent to the original?

CodePudding user response：

No, the refactor is not equivalent to the original. x..y evaluates to x and discards whatever y evaluates to. In your case, that means that you discard the Future returned by writeAsString, and it therefore would not be awaited. If you want your function to return only after writeAsString completes, you cannot use it with ...

If you want to avoid having the file variable, you would need to do:

return await (await makeFileObject(filename)).writeAsString(content);

However, I think that the original is more readable, and I would stick with that.