Simplify the install and uninstall commands and improve tests.

tests/commands_test.py

@@ -0,0 +1,37 @@
+
+import os
+import os.path
+import pkg_resources
+import stat
+
+from pre_commit.commands import install
+from pre_commit.commands import uninstall
+from pre_commit.runner import Runner
+
+
+def test_install_pre_commit(empty_git_dir):
+    runner = Runner(empty_git_dir)
+    ret = install(runner)
+    assert ret == 0
+    assert os.path.exists(runner.pre_commit_path)
+    pre_commit_contents = open(runner.pre_commit_path).read()
+    pre_commit_sh = pkg_resources.resource_filename('pre_commit', 'resources/pre-commit.sh')
+    expected_contents = open(pre_commit_sh).read()
+    assert pre_commit_contents == expected_contents
+    stat_result = os.stat(runner.pre_commit_path)
+    assert stat_result.st_mode & (stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)
+
+
+def test_uninstall_pre_commit_does_not_blow_up_when_not_there(empty_git_dir):
+    runner = Runner(empty_git_dir)
+    ret = uninstall(runner)
+    assert ret == 0
+
+
+def test_uninstall(empty_git_dir):
+    runner = Runner(empty_git_dir)
+    assert not os.path.exists(runner.pre_commit_path)
+    install(runner)
+    assert os.path.exists(runner.pre_commit_path)
+    uninstall(runner)
+    assert not os.path.exists(runner.pre_commit_path)