Test pre-commit hook with black and flake8 #142

jupytext/formats.py

@@ -408,8 +408,8 @@ def long_form_one_format(jupytext_format, metadata=None):
     if not ext.startswith('.'):
         ext = '.' + ext
 
-    if ext == '.auto' and metadata:
-        ext = auto_ext_from_metadata(metadata)
+    if ext == '.auto':
+        ext = auto_ext_from_metadata(metadata) or '.py'
 
     fmt['extension'] = ext
     return fmt

tests/test_black.py

@@ -3,24 +3,13 @@
 from shutil import copyfile
 from testfixtures import compare
 from nbformat.v4.nbbase import new_notebook, new_code_cell
-from .utils import list_notebooks
+from .utils import list_notebooks, requires_black, requires_flake8, requires_autopep8
+
 from jupytext import readf, writef
 from jupytext.cli import system, jupytext, pipe_notebook
 from jupytext.combine import black_invariant
 
 
-def tool_version(tool):
-    try:
-        return system(tool, '--version')
-    except OSError:  # pragma: no cover
-        return None
-
-
-requires_black = pytest.mark.skipif(not tool_version('black'), reason='black not found')
-requires_flake8 = pytest.mark.skipif(not tool_version('flake8'), reason='flake8 not found')
-requires_autopep8 = pytest.mark.skipif(not tool_version('autopep8'), reason='autopep8 not found')
-
-
 @requires_black
 @pytest.mark.parametrize('nb_file', list_notebooks('ipynb_py'))
 def test_apply_black_on_python_notebooks(nb_file, tmpdir):

tests/test_cli.py

@@ -5,13 +5,13 @@
 from shutil import copyfile
 from testfixtures import compare
 from argparse import ArgumentTypeError
-from nbformat.v4.nbbase import new_notebook, new_markdown_cell
+from nbformat.v4.nbbase import new_notebook, new_markdown_cell, new_code_cell
 from jupytext import __version__
 from jupytext import readf, writef, writes
 from jupytext.cli import parse_jupytext_args, jupytext, jupytext_cli, system, str2bool
 from jupytext.compare import compare_notebooks
 from jupytext.paired_paths import paired_paths
-from .utils import list_notebooks
+from .utils import list_notebooks, requires_black, requires_flake8
 
 
 def test_str2bool():
@@ -350,6 +350,47 @@ def git(*args):
     assert os.path.isfile(tmp_md)
 
 
+@requires_black
+@requires_flake8
+def test_pre_commit_hook_sync_black_flake8(tmpdir):
+    def git(*args):
+        print(system('git', *args, cwd=str(tmpdir)))
+
+    git('init')
+    git('status')
+    hook = str(tmpdir.join('.git/hooks/pre-commit'))
+    with open(hook, 'w') as fp:
+        fp.write('#!/bin/sh\n'
+                 '# Pair ipynb notebooks to a python file, reformat content with black, and run flake8\n'
+                 '# Note: this hook only acts on ipynb files. When pulling, run jupytext --sync manually to '
+                 'update the ipynb file.\n'
+                 'jupytext --pre-commit --from ipynb --set-formats ipynb,py --sync --pipe black --check flake8\n')
+
+    st = os.stat(hook)
+    os.chmod(hook, st.st_mode | stat.S_IEXEC)
+
+    tmp_ipynb = str(tmpdir.join('notebook.ipynb'))
+    tmp_py = str(tmpdir.join('notebook.py'))
+    nb = new_notebook(cells=[new_code_cell(source='1+    1')])
+
+    writef(nb, tmp_ipynb)
+    git('add', 'notebook.ipynb')
+    git('status')
+    git('commit', '-m', 'created')
+    git('status')
+    assert os.path.isfile(tmp_py)
+    assert os.path.isfile(tmp_ipynb)
+    with open(tmp_py) as fp:
+        assert fp.read().splitlines()[-1] == '1 + 1'
+
+    nb = new_notebook(cells=[new_code_cell(source='"""trailing   \nwhitespace"""')])
+    writef(nb, tmp_ipynb)
+    git('add', 'notebook.ipynb')
+    git('status')
+    with pytest.raises(SystemExit):  # not flake8
+        git('commit', '-m', 'created')
+
+
 def test_manual_call_of_pre_commit_hook(tmpdir):
     tmp_ipynb = str(tmpdir.join('notebook.ipynb'))
     tmp_py = str(tmpdir.join('notebook.py'))

tests/utils.py

@@ -2,12 +2,25 @@
 import sys
 import re
 import pytest
+from jupytext.cli import system
 
 skip_if_dict_is_not_ordered = pytest.mark.skipif(
     sys.version_info < (3, 6),
     reason="unordered dict result in changes in chunk options")
 
 
+def tool_version(tool):
+    try:
+        return system(tool, '--version')
+    except OSError:  # pragma: no cover
+        return None
+
+
+requires_black = pytest.mark.skipif(not tool_version('black'), reason='black not found')
+requires_flake8 = pytest.mark.skipif(not tool_version('flake8'), reason='flake8 not found')
+requires_autopep8 = pytest.mark.skipif(not tool_version('autopep8'), reason='autopep8 not found')
+
+
 def list_notebooks(path='ipynb', skip='World'):
     """All notebooks in the directory notebooks/path,
     or in the package itself"""