Refactoring: Path API compatibility with pathlib

Refactored dupeGuru to make hscommon.path's API a bit close to pathlib's
API. It's not 100% compatible yet, but it's much better than before.

This is more of a hscommon refactoring than a dupeguru one, but since
duepGuru is the main user of Path, it was the driver behind the
refactoring.

This refactoring also see the introduction of @pathify, which ensure
Path arguments. Previously, we were often unsure of whether the caller
of a function was passing a Path or a str. This problem is now solved
and this allows us to remove hscommon.io, an ill-conceived attempt to
solve that same ambiguity problem.

Fixes #235.

core/tests/app_test.py

@@ -11,7 +11,6 @@ import os.path as op
 import logging
 
 from pytest import mark
-from hscommon import io
 from hscommon.path import Path
 import hscommon.conflict
 import hscommon.util
@@ -57,7 +56,7 @@ class TestCaseDupeGuru:
         # for this unit is pathetic. What's done is done. My approach now is to add tests for
         # every change I want to make. The blowup was caused by a missing import.
         p = Path(str(tmpdir))
-        io.open(p + 'foo', 'w').close()
+        p['foo'].open('w').close()
         monkeypatch.setattr(hscommon.conflict, 'smart_copy', log_calls(lambda source_path, dest_path: None))
         # XXX This monkeypatch is temporary. will be fixed in a better monkeypatcher.
         monkeypatch.setattr(app, 'smart_copy', hscommon.conflict.smart_copy)
@@ -73,14 +72,14 @@ class TestCaseDupeGuru:
     
     def test_copy_or_move_clean_empty_dirs(self, tmpdir, monkeypatch):
         tmppath = Path(str(tmpdir))
-        sourcepath = tmppath + 'source'
-        io.mkdir(sourcepath)
-        io.open(sourcepath + 'myfile', 'w')
+        sourcepath = tmppath['source']
+        sourcepath.mkdir()
+        sourcepath['myfile'].open('w')
         app = TestApp().app
         app.directories.add_path(tmppath)
         [myfile] = app.directories.get_files()
         monkeypatch.setattr(app, 'clean_empty_dirs', log_calls(lambda path: None))
-        app.copy_or_move(myfile, False, tmppath + 'dest', 0)
+        app.copy_or_move(myfile, False, tmppath['dest'], 0)
         calls = app.clean_empty_dirs.calls
         eq_(1, len(calls))
         eq_(sourcepath, calls[0]['path'])
@@ -104,8 +103,8 @@ class TestCaseDupeGuru:
         # If the ignore_hardlink_matches option is set, don't match files hardlinking to the same
         # inode.
         tmppath = Path(str(tmpdir))
-        io.open(tmppath + 'myfile', 'w').write('foo')
-        os.link(str(tmppath + 'myfile'), str(tmppath + 'hardlink'))
+        tmppath['myfile'].open('w').write('foo')
+        os.link(str(tmppath['myfile']), str(tmppath['hardlink']))
         app = TestApp().app
         app.directories.add_path(tmppath)
         app.scanner.scan_type = ScanType.Contents
@@ -171,8 +170,8 @@ class TestCaseDupeGuruWithResults:
         self.rtable.refresh()
         tmpdir = request.getfuncargvalue('tmpdir')
         tmppath = Path(str(tmpdir))
-        io.mkdir(tmppath + 'foo')
-        io.mkdir(tmppath + 'bar')
+        tmppath['foo'].mkdir()
+        tmppath['bar'].mkdir()
         self.app.directories.add_path(tmppath)
     
     def test_GetObjects(self, do_setup):
@@ -417,11 +416,11 @@ class TestCaseDupeGuru_renameSelected:
     def pytest_funcarg__do_setup(self, request):
         tmpdir = request.getfuncargvalue('tmpdir')
         p = Path(str(tmpdir))
-        fp = open(str(p + 'foo bar 1'),mode='w')
+        fp = open(str(p['foo bar 1']),mode='w')
         fp.close()
-        fp = open(str(p + 'foo bar 2'),mode='w')
+        fp = open(str(p['foo bar 2']),mode='w')
         fp.close()
-        fp = open(str(p + 'foo bar 3'),mode='w')
+        fp = open(str(p['foo bar 3']),mode='w')
         fp.close()
         files = fs.get_files(p)
         for f in files:
@@ -444,7 +443,7 @@ class TestCaseDupeGuru_renameSelected:
         g = self.groups[0]
         self.rtable.select([1])
         assert app.rename_selected('renamed')
-        names = io.listdir(self.p)
+        names = [p.name for p in self.p.listdir()]
         assert 'renamed' in names
         assert 'foo bar 2' not in names
         eq_(g.dupes[0].name, 'renamed')
@@ -457,7 +456,7 @@ class TestCaseDupeGuru_renameSelected:
         assert not app.rename_selected('renamed')
         msg = logging.warning.calls[0]['msg']
         eq_('dupeGuru Warning: list index out of range', msg)
-        names = io.listdir(self.p)
+        names = [p.name for p in self.p.listdir()]
         assert 'renamed' not in names
         assert 'foo bar 2' in names
         eq_(g.dupes[0].name, 'foo bar 2')
@@ -470,7 +469,7 @@ class TestCaseDupeGuru_renameSelected:
         assert not app.rename_selected('foo bar 1')
         msg = logging.warning.calls[0]['msg']
         assert msg.startswith('dupeGuru Warning: \'foo bar 1\' already exists in')
-        names = io.listdir(self.p)
+        names = [p.name for p in self.p.listdir()]
         assert 'foo bar 1' in names
         assert 'foo bar 2' in names
         eq_(g.dupes[0].name, 'foo bar 2')
@@ -480,9 +479,9 @@ class TestAppWithDirectoriesInTree:
     def pytest_funcarg__do_setup(self, request):
         tmpdir = request.getfuncargvalue('tmpdir')
         p = Path(str(tmpdir))
-        io.mkdir(p + 'sub1')
-        io.mkdir(p + 'sub2')
-        io.mkdir(p + 'sub3')
+        p['sub1'].mkdir()
+        p['sub2'].mkdir()
+        p['sub3'].mkdir()
         app = TestApp()
         self.app = app.app
         self.dtree = app.dtree