From ebe5132576b9f84859e018b2430fa9a21e307716 Mon Sep 17 00:00:00 2001
From: Anthony Sottile <asottile@umich.edu>
Date: Sun, 14 Oct 2018 12:24:59 -0700
Subject: [PATCH] Replace pkg_resources.get_distribution with
 importlib-metadata

---
 pre_commit/constants.py  | 5 ++---
 pre_commit/repository.py | 8 ++++----
 pre_commit/util.py       | 5 +++++
 setup.py                 | 2 ++
 tests/util_test.py       | 7 +++++++
 5 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/pre_commit/constants.py b/pre_commit/constants.py
index 48ba2cb9..a8cdc2e5 100644
--- a/pre_commit/constants.py
+++ b/pre_commit/constants.py
@@ -1,7 +1,7 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
-import pkg_resources
+import importlib_metadata  # TODO: importlib.metadata py38?
 
 CONFIG_FILE = '.pre-commit-config.yaml'
 MANIFEST_FILE = '.pre-commit-hooks.yaml'
@@ -18,8 +18,7 @@ INSTALLED_STATE_VERSION = '1'
 # Bump when modifying `empty_template`
 LOCAL_REPO_VERSION = '1'
 
-VERSION = pkg_resources.get_distribution('pre-commit').version
-VERSION_PARSED = pkg_resources.parse_version(VERSION)
+VERSION = importlib_metadata.version('pre_commit')
 
 # `manual` is not invoked by any installed git hook.  See #719
 STAGES = ('commit', 'commit-msg', 'manual', 'push')
diff --git a/pre_commit/repository.py b/pre_commit/repository.py
index 278f31a2..d718c2ff 100644
--- a/pre_commit/repository.py
+++ b/pre_commit/repository.py
@@ -8,7 +8,6 @@ import pipes
 import shutil
 import sys
 
-import pkg_resources
 from cached_property import cached_property
 from cfgv import apply_defaults
 from cfgv import validate
@@ -23,6 +22,7 @@ from pre_commit.clientlib import MANIFEST_HOOK_DICT
 from pre_commit.languages.all import languages
 from pre_commit.languages.helpers import environment_dir
 from pre_commit.prefix import Prefix
+from pre_commit.util import parse_version
 
 
 logger = logging.getLogger('pre_commit')
@@ -110,13 +110,13 @@ def _hook(*hook_dicts):
     for dct in rest:
         ret.update(dct)
 
-    version = pkg_resources.parse_version(ret['minimum_pre_commit_version'])
-    if version > C.VERSION_PARSED:
+    version = ret['minimum_pre_commit_version']
+    if parse_version(version) > parse_version(C.VERSION):
         logger.error(
             'The hook `{}` requires pre-commit version {} but version {} '
             'is installed.  '
             'Perhaps run `pip install --upgrade pre-commit`.'.format(
-                ret['id'], version, C.VERSION_PARSED,
+                ret['id'], version, C.VERSION,
             ),
         )
         exit(1)
diff --git a/pre_commit/util.py b/pre_commit/util.py
index bcb47c3f..55210f10 100644
--- a/pre_commit/util.py
+++ b/pre_commit/util.py
@@ -211,3 +211,8 @@ def copy_tree_to_path(src_dir, dest_dir):
             shutil.copytree(srcname, destname)
         else:
             shutil.copy(srcname, destname)
+
+
+def parse_version(s):
+    """poor man's version comparison"""
+    return tuple(int(p) for p in s.split('.'))
diff --git a/setup.py b/setup.py
index 3eb04d8a..82a70371 100644
--- a/setup.py
+++ b/setup.py
@@ -40,6 +40,8 @@ setup(
         'cached-property',
         'cfgv>=1.0.0',
         'identify>=1.0.0',
+        # if this makes it into python3.8 move to extras_require
+        'importlib-metadata',
         'nodeenv>=0.11.1',
         'pyyaml',
         'six',
diff --git a/tests/util_test.py b/tests/util_test.py
index 967163e4..56eb5aaa 100644
--- a/tests/util_test.py
+++ b/tests/util_test.py
@@ -9,6 +9,7 @@ from pre_commit.util import CalledProcessError
 from pre_commit.util import clean_path_on_failure
 from pre_commit.util import cmd_output
 from pre_commit.util import memoize_by_cwd
+from pre_commit.util import parse_version
 from pre_commit.util import tmpdir
 from testing.util import cwd
 
@@ -117,3 +118,9 @@ def test_cmd_output_exe_not_found():
     ret, out, _ = cmd_output('i-dont-exist', retcode=None)
     assert ret == 1
     assert out == 'Executable `i-dont-exist` not found'
+
+
+def test_parse_version():
+    assert parse_version('0.0') == parse_version('0.0')
+    assert parse_version('0.1') > parse_version('0.0')
+    assert parse_version('2.1') >= parse_version('2')