Wishes for FileIOException

[peter-ahe-google]

I'm currently looking at what dart2js reports when it cannot read a file and noticed a few things about FileIOException that I wish were different.

1. I wish that I could extract the file name directly from the exception object.
2. I wish the osError field had a less low-level feel to it.

Currently, this is how I deal with FileIOException:

...
    } catch (FileIOException ex) {
      print('Error reading ${relativize(cwd, uri)}: ${ex.osError}.');
      exit(1);
    }

This prints:

Error reading fiskefisk: OS Error: No such file or directory, errno = 2.

This message contains a lot of information that is nice for a developer, but to my user, I would like to simply print:

Error reading fiskefisk: No such file or directory.

[madsager]

Added this to the Later milestone.

[andersjohnsen]

By default, we want the exceptions to provide as much info as possible for quick debugging.

That said, it should be quite easy to customize the output of exceptions, as both FileException.message and OSError.message are available.

In the example above it be changed to:

print('Error reading ${relativize(cwd, uri)}: ${ex.osError.message}.');

If you are unable to extract the info needed, please open the issue again.

---

Added AsDesigned label.

[peter-ahe-google]

I don't think the class OSError existed when I wrote this request. OSError definitely satisfies my second wish (and enables me to produce a better error message). Thank you for that.

I still wish that FileException would contain the name of the file.

---

Added Triaged label.

[andersjohnsen]

Set owner to @Skabet.
Added Started label.

[andersjohnsen]

I've landed FileException.path in r24523.

---

Added Fixed label.

[peter-ahe-google]

Wow, I got two wishes granted! Thank you.

[kevmoo]

Removed Area-IO label.
Added Area-Library, Library-IO labels.