Allow projects to drop 'python_version>=3.x' version specifier

For projects that have gone Python 3, having to keep the
'python_version' specifiers can add otherwise unnecessary noise. Special
case these until such a time as Python 2.7 is history and we can drop
all these Python version specifiers.

Change-Id: Ie6dba8bc78dcd5fa95c7ac15b0a3770cdef8ad95
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>
Co-Authored-By: Zane Bitter <zbitter@redhat.com>

openstack_requirements/check.py

@@ -15,6 +15,7 @@
 # under the License.
 
 import collections
+import re
 
 from packaging import markers
 from packaging import specifiers
@@ -23,6 +24,7 @@ from openstack_requirements import project
 from openstack_requirements import requirement
 
 MIN_PY_VERSION = '3.5'
+PY3_SPECIFIER_RE = re.compile(r'python_version(==|>=|>)[\'"]3\.\d+[\'"]')
 
 
 class RequirementsList(object):
@@ -85,7 +87,7 @@ def _get_exclusions(req):
     )
 
 
-def _is_requirement_in_global_reqs(local_req, global_reqs):
+def _is_requirement_in_global_reqs(local_req, global_reqs, allow_3_only=False):
     req_exclusions = _get_exclusions(local_req)
     for global_req in global_reqs:
 
@@ -94,6 +96,13 @@ def _is_requirement_in_global_reqs(local_req, global_reqs):
             local_req_val = getattr(local_req, aname)
             global_req_val = getattr(global_req, aname)
             if local_req_val != global_req_val:
+                # if global requirements specifies a python 3 version specifier
+                # but a project doesn't, allow it since python 3-only is okay
+                if (allow_3_only and matching and
+                        aname == 'markers' and not local_req_val):
+                    if PY3_SPECIFIER_RE.match(global_req_val):
+                        continue
+
                 print('WARNING: possible mismatch found for package '
                       '"{}"'.format(local_req.package))
                 print('   Attribute "{}" does not match'.format(aname))
@@ -183,7 +192,7 @@ def _validate_one(name, reqs, blacklist, global_reqs, allow_3_only=False):
         else:
             counts[''] = counts.get('', 0) + 1
         if not _is_requirement_in_global_reqs(
-                req, global_reqs[name]):
+                req, global_reqs[name], allow_3_only):
             return True
         # check for minimum being defined
         min = [s for s in req.specifiers.split(',') if '>' in s]

openstack_requirements/tests/test_check.py

@@ -55,6 +55,18 @@ class TestIsReqInGlobalReqs(testtools.TestCase):
             )
         )
 
+    def test_match_without_python3_markers(self):
+        req = requirement.parse(textwrap.dedent("""
+        withmarker>=1.5'
+        """))['withmarker'][0][0]
+        self.assertTrue(
+            check._is_requirement_in_global_reqs(
+                req,
+                self.global_reqs['withmarker'],
+                allow_3_only=True
+            )
+        )
+
     def test_name_mismatch(self):
         req = requirement.parse('wrongname>=1.2,!=1.4')['wrongname'][0][0]
         self.assertFalse(
@@ -358,6 +370,33 @@ class TestValidateOne(testtools.TestCase):
             )
         )
 
+    def test_new_item_matches_py3_allowed(self):
+        # If the global list has multiple entries for an item but the branch
+        # allows python 3 only, then only the py3 entries need to match.
+        # Requirements without a python_version marker should always be used.
+        r_content = textwrap.dedent("""
+        name>=1.5
+        other-name
+        """)
+        reqs = [
+            r
+            for r, line in requirement.parse(r_content)['name']
+        ]
+        global_reqs = check.get_global_reqs(textwrap.dedent("""
+        name>=1.5;python_version>='3.5'
+        name>=1.2,!=1.4;python_version=='2.6'
+        other-name
+        """))
+        self.assertFalse(
+            check._validate_one(
+                'name',
+                reqs=reqs,
+                blacklist=requirement.parse(''),
+                global_reqs=global_reqs,
+                allow_3_only=True,
+            )
+        )
+
     def test_new_item_matches_py3_allowed_with_py2(self):
         # If the global list has multiple entries for an item but the branch
         # allows python 3 only, then only the py3 entries need to match.