Add integration test for existing install behaviour

pre_commit/store.py

@@ -22,7 +22,10 @@ def _get_default_directory():
     `Store.get_default_directory` can be mocked in tests and
     `_get_default_directory` can be tested.
     """
-    return os.path.join(os.environ['HOME'], '.pre-commit')
+    return os.environ.get(
+        'PRE_COMMIT_HOME',
+        os.path.join(os.environ['HOME'], '.pre-commit'),
+    )
 
 
 class Store(object):

testing/fixtures.py

@@ -66,4 +66,7 @@ def make_consuming_repo(tmpdir_factory, repo_source):
     config = make_config_from_repo(path)
     git_path = git_dir(tmpdir_factory)
     write_config(git_path, config)
+    with local.cwd(git_path):
+        git('add', C.CONFIG_FILE)
+        git('commit', '-m', 'Add hooks config')
     return git_path

tests/commands/install_test.py

@@ -4,12 +4,38 @@ from __future__ import unicode_literals
 import io
 import os
 import os.path
+import re
 import pkg_resources
+import subprocess
 import stat
+from plumbum import local
 
 from pre_commit.commands.install import install
 from pre_commit.runner import Runner
 from testing.fixtures import git_dir
+from testing.fixtures import make_consuming_repo
+
+
+def _get_commit_output(tmpdir_factory):
+    # Don't want to write to home directory
+    env = dict(os.environ, **{'PRE_COMMIT_HOME': tmpdir_factory.get()})
+    return local['git'](
+        'commit', '-m', 'Commit!', '--allow-empty',
+        # git commit puts pre-commit to stderr
+        stderr=subprocess.STDOUT,
+        env=env,
+    )
+
+
+NORMAL_PRE_COMMIT_RUN = re.compile(
+    r'^\[INFO\] Installing environment for .+.\n'
+    r'\[INFO\] Once installed this environment will be reused.\n'
+    r'\[INFO\] This may take a few minutes...\n'
+    r'Bash hook'
+    r'\.+'
+    r'\(no files to check\) Skipped\n'
+    r'\[master [a-f0-9]{7}\] Commit!\n$'
+)
 
 
 def test_install_pre_commit(tmpdir_factory):
@@ -26,3 +52,22 @@ def test_install_pre_commit(tmpdir_factory):
     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_install_pre_commit_and_run(tmpdir_factory):
+    path = make_consuming_repo(tmpdir_factory, 'script_hooks_repo')
+    with local.cwd(path):
+        assert install(Runner(path)) == 0
+
+        output = _get_commit_output(tmpdir_factory)
+        assert NORMAL_PRE_COMMIT_RUN.match(output)
+
+
+def test_install_idempotent(tmpdir_factory):
+    path = make_consuming_repo(tmpdir_factory, 'script_hooks_repo')
+    with local.cwd(path):
+        assert install(Runner(path)) == 0
+        assert install(Runner(path)) == 0
+
+        output = _get_commit_output(tmpdir_factory)
+        assert NORMAL_PRE_COMMIT_RUN.match(output)

tests/store_test.py

@@ -31,6 +31,14 @@ def test_get_default_directory_defaults_to_home():
     assert ret == os.path.join(os.environ['HOME'], '.pre-commit')
 
 
+def test_uses_environment_variable_when_present():
+    with mock.patch.dict(
+        os.environ, {'PRE_COMMIT_HOME': '/tmp/pre_commit_home'}
+    ):
+        ret = _get_default_directory()
+        assert ret == '/tmp/pre_commit_home'
+
+
 def test_store_require_created(store):
     assert not os.path.exists(store.directory)
     store.require_created()