Add dotfile class rework

This version of the dotfile class uses py.path.local and removes much of
the cruft of using os.path and it's associated requirements.

There are still a few things missing, namely dry_run mode where commands
are printed instead of executed and force sync.  They will be included
as required.

2 files changed, 155 insertions, 0 deletions

diff --git a/dotfiles/dotfile.py b/dotfiles/dotfile.py
new file mode 100644
index 0000000..ed0b2cb
--- /dev/null
+++ b/dotfiles/dotfile.py
@@ -0,0 +1,43 @@
+import errno
+
+
+class Dotfile:
+    """
+    This class implements the 'dotfile' abstraction.
+
+    A dotfile has two primary attributes:
+
+    name -- name of dotfile in the home directory (~/.vimrc)
+    target -- target the dotfile should point to (~/Dotfiles/vimrc)
+
+    The above attributes are both py.path.local objects.
+
+    The goal is for there to be no special logic or stored global state.  Only
+    the implementation of three operations made available to the caller:
+
+    add -- moves a dotfile into the repository and replaces it with a symlink
+    remove -- the opposite of add
+    sync -- ensure that each repository file has a corresponding symlink
+
+    This is where most filesystem operaitons (link, delete, etc) should be
+    called, and not in the layers above.
+    """
+
+    def __init__(self, name, target):
+        self.name = name
+        self.target = target
+
+    def add(self):
+        if self.target.check(exists=1):
+            raise OSError(errno.EEXIST, self.target)
+        self.name.move(self.target)
+        self.sync()
+
+    def remove(self):
+        if self.target.check(exists=0):
+            raise OSError(errno.ENOENT, self.target)
+        self.name.remove()
+        self.target.move(self.name)
+
+    def sync(self):
+        self.name.mksymlinkto(self.target)
diff --git a/tests/test_dotfile.py b/tests/test_dotfile.py
new file mode 100644
index 0000000..b854859
--- /dev/null
+++ b/tests/test_dotfile.py
@@ -0,0 +1,112 @@
+import pytest
+import py.error
+from dotfiles.dotfile import Dotfile
+
+
+class TestAdd:
+
+    def test_add(self, tmpdir):
+
+        repo = tmpdir.ensure("Dotfiles", dir=1)
+        name = tmpdir.ensure(".vimrc")
+        target = repo.join("vimrc")
+
+        dotfile = Dotfile(name, target)
+        dotfile.add()
+
+        assert target.check(file=1, link=0)
+        assert name.check(file=1, link=1)
+        assert name.samefile(target)
+
+    def test_add_twice(self, tmpdir):
+
+        repo = tmpdir.ensure("Dotfiles", dir=1)
+        name = tmpdir.ensure(".vimrc")
+        target = repo.join("vimrc")
+
+        dotfile = Dotfile(name, target)
+        dotfile.add()
+
+        assert target.check(file=1, link=0)
+        assert name.check(file=1, link=1)
+        assert name.samefile(target)
+
+        with pytest.raises(OSError):
+            dotfile.add()
+
+        assert target.check(file=1, link=0)
+        assert name.check(file=1, link=1)
+        assert name.samefile(target)
+
+
+class TestRemove:
+
+    def test_remove(self, tmpdir):
+
+        repo = tmpdir.ensure("Dotfiles", dir=1)
+        name = tmpdir.join(".vimrc")
+        target = repo.ensure("vimrc")
+
+        name.mksymlinkto(target)
+
+        dotfile = Dotfile(name, target)
+        dotfile.remove()
+
+        assert False == target.check()
+        assert name.check(file=1, link=0)
+
+    def test_remove_twice(self, tmpdir):
+
+        repo = tmpdir.ensure("Dotfiles", dir=1)
+        name = tmpdir.join(".vimrc")
+        target = repo.ensure("vimrc")
+
+        name.mksymlinkto(target)
+
+        dotfile = Dotfile(name, target)
+        dotfile.remove()
+
+        assert False == target.check()
+        assert name.check(file=1, link=0)
+
+        with pytest.raises(OSError):
+            dotfile.remove()
+
+        assert False == target.check()
+        assert name.check(file=1, link=0)
+
+
+class TestSync:
+
+    def test_sync(self, tmpdir):
+
+        repo = tmpdir.ensure("Dotfiles", dir=1)
+        name = tmpdir.join(".vimrc")
+        target = repo.ensure("vimrc")
+
+        dotfile = Dotfile(name, target)
+        dotfile.sync()
+
+        assert target.check(file=1, link=0)
+        assert name.check(file=1, link=1)
+        assert name.samefile(target)
+
+    def test_sync_twice(self, tmpdir):
+
+        repo = tmpdir.ensure("Dotfiles", dir=1)
+        name = tmpdir.join(".vimrc")
+        target = repo.ensure("vimrc")
+
+        dotfile = Dotfile(name, target)
+        dotfile.sync()
+
+        assert target.check(file=1, link=0)
+        assert name.check(file=1, link=1)
+        assert name.samefile(target)
+
+        with pytest.raises(py.error.EEXIST):
+            dotfile.sync()
+
+        assert target.check(file=1, link=0)
+        assert name.check(file=1, link=1)
+        assert name.samefile(target)