fix gitlab #4: make {release} tag optional

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})?",
 }

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"              , ""),
 ]
 
 

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)