From b893995cbc672664703854de34bfa33d66777fbd Mon Sep 17 00:00:00 2001
From: Manuel Barkhau <mbarkhau@gmail.com>
Date: Tue, 9 Jul 2019 08:21:57 +0200
Subject: [PATCH] fix gitlab #4: make {release} tag optional

---
 src/pycalver/patterns.py |  2 +-
 test/test_patterns.py    |  4 ++--
 test/test_rewrite.py     | 28 ++++++++++++++++++++++++++++
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/src/pycalver/patterns.py b/src/pycalver/patterns.py
index b7527c7..f3c6f49 100644
--- a/src/pycalver/patterns.py
+++ b/src/pycalver/patterns.py
@@ -78,7 +78,7 @@ COMPOSITE_PART_PATTERNS = {
     'semver'         : r"{MAJOR}\.{MINOR}\.{PATCH}",
     'release_tag'    : r"{tag}",
     'build'          : r"\.{bid}",
-    'release'        : r"-{tag}",
+    'release'        : r"(?:-{tag})?",
     # depricated
     'pep440_version': r"{year}{month}\.{BID}(?:{pep440_tag})?",
 }
diff --git a/test/test_patterns.py b/test/test_patterns.py
index f0d0716..dfb31d4 100644
--- a/test/test_patterns.py
+++ b/test/test_patterns.py
@@ -37,8 +37,8 @@ PATTERN_PART_CASES = [
     ("release"        , "-dev"               , "-dev"),
     ("release"        , "-rc"                , "-rc"),
     ("release"        , "-post"              , "-post"),
-    ("release"        , "-pre"               , None),
-    ("release"        , "alpha"              , None),
+    ("release"        , "-pre"               , ""),
+    ("release"        , "alpha"              , ""),
 ]
 
 
diff --git a/test/test_rewrite.py b/test/test_rewrite.py
index d9d4613..3b698f2 100644
--- a/test/test_rewrite.py
+++ b/test/test_rewrite.py
@@ -100,3 +100,31 @@ def test_error_bad_pattern():
             assert False, "expected rewrite.NoPatternMatch"
         except rewrite.NoPatternMatch as ex:
             assert "setup.py" in str(ex)
+
+
+OPTIONAL_RELEASE_FIXTURE = """
+# SPDX-License-Identifier: BSD
+__version__ = "2018.0002-beta"
+"""
+
+
+def test_optional_release():
+    old_lines = OPTIONAL_RELEASE_FIXTURE.splitlines()
+    pattern   = "{year}.{build_no}{release}"
+    patterns  = ['__version__ = "{year}.{build_no}{release}"']
+
+    new_vinfo = version.parse_version_info("2019.0003", pattern)
+    new_lines = rewrite.rewrite_lines(patterns, new_vinfo, old_lines)
+
+    assert len(new_lines) == len(old_lines)
+    assert "2019.0003" not in "\n".join(old_lines)
+    new_text = "\n".join(new_lines)
+    assert "2019.0003" in new_text
+
+    new_vinfo = version.parse_version_info("2019.0004-beta", pattern)
+    new_lines = rewrite.rewrite_lines(patterns, new_vinfo, old_lines)
+
+    # make sure optional release tag is added back on
+    assert len(new_lines) == len(old_lines)
+    assert "2019.0004-beta" not in "\n".join(old_lines)
+    assert "2019.0004-beta" in "\n".join(new_lines)