WIP: mostly scratch code still

src/pycalver/vcs.py

@@ -0,0 +1,111 @@
+# This file is part of the pycalver project
+# https://github.com/mbarkhau/pycalver
+#
+# (C) 2018 Manuel Barkhau (@mbarkhau)
+# SPDX-License-Identifier: MIT
+#
+# pycalver/vcs.py (this file) is based on code from the
+# bumpversion project: https://github.com/peritus/bumpversion
+# MIT License - (C) 2013-2014 Filip Noetzel
+
+import os
+import logging
+import tempfile
+import subprocess as sp
+
+
+log = logging.getLogger("pycalver.vcs")
+
+
+class WorkingDirectoryIsDirtyException(Exception):
+
+    def __init__(self, message):
+        self.message = message
+
+
+class BaseVCS:
+
+    @classmethod
+    def commit(cls, message):
+        f = tempfile.NamedTemporaryFile("wb", delete=False)
+        f.write(message.encode("utf-8"))
+        f.close()
+        cmd = cls._COMMIT_COMMAND + [f.name]
+        env_items = list(os.environ.items()) + [(b"HGENCODING", b"utf-8")]
+        sp.check_output(cmd, env=dict(env_items))
+        os.unlink(f.name)
+
+    @classmethod
+    def is_usable(cls):
+        try:
+            return sp.call(
+                cls._TEST_USABLE_COMMAND,
+                stderr=sp.PIPE,
+                stdout=sp.PIPE,
+            ) == 0
+        except OSError as e:
+            if e.errno == 2:
+                # mercurial is not installed then, ok.
+                return False
+            raise
+
+    @classmethod
+    def assert_nondirty(cls):
+        status_output = sp.check_output(cls._STATUS_COMMAND)
+        lines = [
+            line.strip()
+            for line in status_output.splitlines()
+            if not line.strip().startswith(b"??")
+        ]
+
+        if lines:
+            cleaned_output = b"\n".join(lines)
+            cls_name = cls.__name__
+            raise WorkingDirectoryIsDirtyException(
+                f"{cls_name} working directory is not clean:\n{cleaned_output}"
+            )
+
+
+class Git(BaseVCS):
+
+    _TEST_USABLE_COMMAND = ["git", "rev-parse", "--git-dir"]
+    _COMMIT_COMMAND = ["git", "commit", "-F"]
+    _STATUS_COMMAND = ["git", "status", "--porcelain"]
+
+    @classmethod
+    def tag(cls, name):
+        sp.check_output(["git", "tag", name])
+
+
+class Mercurial(BaseVCS):
+
+    _TEST_USABLE_COMMAND = ["hg", "root"]
+    _COMMIT_COMMAND = ["hg", "commit", "--logfile"]
+    _STATUS_COMMAND = ["hg", "status", "-mard"]
+
+    @classmethod
+    def tag(cls, name):
+        sp.check_output(["hg", "tag", name])
+
+
+VCS = [Git, Mercurial]
+
+
+def get_vcs(allow_dirty=False):
+    for vcs in VCS:
+        if not vcs.is_usable():
+            continue
+
+        if not allow_dirty:
+            try:
+                vcs.assert_nondirty()
+            except WorkingDirectoryIsDirtyException as e:
+                log.warn(
+                    f"{e.message}\n\n"
+                    f"Use --allow-dirty to override this if you know what you're doing."
+                )
+                raise
+
+        return vcs
+
+    return None