Make nbdiff without arguments work with a hg repo

[tmbb]

This pull request uses python-hglib instead of raw hg commands. This adds another depencency to the project but makes the code much simpler.

I haven't written any tests yet. I might write them in the future, when I have more time.

[tmbb]

(only works when called in the root folder of the repository)

[bpipev]

Good work! It's working. There's one small problem though. It tries to diff unmerged notebooks as well, which it shouldn't.

[tmbb]

I have to study more about hg to fix that (in fact, I usually program solo, and as such I don't understand much about merging changes). Thanks for noticing the issue.

[tmbb]

I've read hg's documentation and aparently, a file is unmerged if and only if the command 'hg resolve --list' returns something like: U filename

Is this right? If it is right, then I know how to fix the problem.

[bpipev]

Yes, I think that is correct.

[tmbb]

How are you testing my pull request? Do you have a repo with unmerged files I could use? I can create it myself, of course. I was just wondering if you have a particulary hairy repository I could test my patch with.

[tarmstrong]

@tmbb : our manual testing scripts aren't terribly documented -- sorry about that -- but you can find them in scripts/.

./make_merge_conflict.py (not the .sh) will create a folder with a git repository in it that you can test with. The examples are very gentle but they do save you the hassle of creating your own merge conflicts.

[tarmstrong]

Strike my last, they are actually reasonably well-documented :) . See the readme at https://github.com/tarmstrong/nbdiff/tree/master/scripts

[tmbb]

nbdiff no longer tries to diff unmerged notebooks

[bpipev]

I've tested your latest changes and here are some bugs I found:

• When running nbdiff not inside a git folder, I get an error:

bobi@bobi-VirtualBox:~/git$ nbdiff
Traceback (most recent call last):
  File "/usr/local/bin/nbdiff", line 9, in <module>
    load_entry_point('nbdiff==1.0.4', 'console_scripts', 'nbdiff')()
  File "/home/bobi/git/nbdiff_other/nbdiff/nbdiff/commands.py", line 120, in diff
    modified_notebooks = vcs.get_modified_notebooks()
  File "/home/bobi/git/nbdiff_other/nbdiff/nbdiff/adapter/hg_adapter.py", line 79, in get_modified_notebooks
    unmerged = [path for (status, path) in client.resolve(listfiles=True)
  File "/usr/local/lib/python2.7/dist-packages/hglib/client.py", line 1257, in resolve
    out = self.rawcommand(args)
  File "/usr/local/lib/python2.7/dist-packages/hglib/client.py", line 179, in rawcommand
    raise error.CommandError(args, ret, out, err)
hglib.error.CommandError: (255, '', "abort: no repository found in '/home/bobi/git' (.hg not found)!")

• When you have a folder structure like hg_diff_root/First_inner/Second_inner/User_Interface.ipynb and run nbdiff inside First_inner, I get an error:

bobi@bobi-VirtualBox:~/git/tests/hg_diff_root/First_inner$ nbdiff
Traceback (most recent call last):
  File "/usr/local/bin/nbdiff", line 9, in <module>
    load_entry_point('nbdiff==1.0.4', 'console_scripts', 'nbdiff')()
  File "/home/bobi/git/nbdiff_other/nbdiff/nbdiff/commands.py", line 120, in diff
    modified_notebooks = vcs.get_modified_notebooks()
  File "/home/bobi/git/nbdiff_other/nbdiff/nbdiff/adapter/hg_adapter.py", line 87, in get_modified_notebooks
    current_local_notebook = open(abspath)
IOError: [Errno 2] No such file or directory: '/home/bobi/git/tests/hg_diff_root/First_inner/First_inner/Second_inner/User_Interface.ipynb'

[tmbb]

@bpipev I can't reproduce your errors, and in my setup the tests pass (the Travis CI build tool says one test fails). Any ideas? (sorry for my inexperience with git, github and version control in general)

[bpipev]

The build error was not your fault. Sometimes it randomly fails for some reason. I just rebuilt it and it's fine. I'm not sure why you can't reproduce the errors though...

[tmbb]

About the error, are you sure you are using either revisions af290f9 or 83b75d6? In one of the older revisions I got those errors, but not anymore

[bpipev]

I'm sure I have the latest revision. When you do hglib.open(dirpath) where dirpath is a path that doesn't have a repo, do you get an exception? Because I don't.

[tmbb]

I get a ServerError exception.

[tmbb]

Well, if you supply an empty string or None it opens the same repo as calling hg in the same repo would open. But if you call it on an invalid nonempty string it raises a ServerError

[bpipev]

No matter what string I give it, I don't get any exception.

[bpipev]

Anyway, for now can you add something like

client = hglib.open(dirpath)
client.root() 
return client, dirpath

to check if it's inside hg repo?

[tmbb]

So, when you run hglib.open(), you don't get an error, but when you run client.root() you get an error. Is that right?

Also, you seem to be testing this in a virtual box. What OS is it emulating? (I can't test it myself in a virtualbox because my computer seems to be far too slow to run it)

[bpipev]

So, when you run hglib.open(), you don't get an error, but when you run client.root() you get an error. Is that right?

That is correct. I think that any function except open would give me that error.

Also, you seem to be testing this in a virtual box. What OS is it emulating? (I can't test it myself in a virtualbox because my computer seems to be far too slow to run it)

I'm running Ubuntu 14.04 64bit.

[tmbb]

The code should work now. The error we depend on is now raised by client.root() instead of hglib.open(path). The code is also much simpler now, because hglib does all the work of trying to find out if we are inside a hg repo and getting its root.

[bpipev]

Looks good to me. Good work!