Add unit tests for manual SOABI detection

tests/unit/test_wheel.py

@@ -294,6 +294,50 @@ def test_version_underscore_conversion(self):
 
 class TestPEP425Tags(object):
 
+    def mock_get_config_var(self, **kwd):
+        """
+        Patch sysconfig.get_config_var for arbitrary keys.
+        """
+        import pip.pep425tags
+
+        get_config_var = pip.pep425tags.sysconfig.get_config_var
+
+        def _mock_get_config_var(var):
+            if var in kwd:
+                return kwd[var]
+            return get_config_var(var)
+        return _mock_get_config_var
+
+    def abi_tag_unicode(self, flags, config_vars):
+        """
+        Used to test ABI tags, verify correct use of the `u` flag
+        """
+        import pip.pep425tags
+
+        config_vars.update({'SOABI': None})
+        base = pip.pep425tags.get_abbr_impl() + pip.pep425tags.get_impl_ver()
+
+        config_vars.update({'Py_UNICODE_SIZE': 2})
+        mock_gcf = self.mock_get_config_var(**config_vars)
+        with patch('pip.pep425tags.sysconfig.get_config_var', mock_gcf):
+            abi_tag = pip.pep425tags.get_abi_tag()
+            assert abi_tag == base + flags
+
+        config_vars.update({'Py_UNICODE_SIZE': 4})
+        mock_gcf = self.mock_get_config_var(**config_vars)
+        with patch('pip.pep425tags.sysconfig.get_config_var', mock_gcf):
+            abi_tag = pip.pep425tags.get_abi_tag()
+            assert abi_tag == base + flags + 'u'
+
+        # On Python >= 3.3, UCS-4 is essentially permanently enabled, and
+        # Py_UNICODE_SIZE is None. SOABI on these builds does not include the
+        # 'u' so manual SOABI detection should not do so either.
+        config_vars.update({'Py_UNICODE_SIZE': None})
+        mock_gcf = self.mock_get_config_var(**config_vars)
+        with patch('pip.pep425tags.sysconfig.get_config_var', mock_gcf):
+            abi_tag = pip.pep425tags.get_abi_tag()
+            assert abi_tag == base + flags
+
     def test_broken_sysconfig(self):
         """
         Test that pep425tags still works when sysconfig is broken.
@@ -314,21 +358,40 @@ def test_no_hyphen_tag(self):
         """
         import pip.pep425tags
 
-        get_config_var = pip.pep425tags.sysconfig.get_config_var
-
-        def mock_soabi(var):
-            if var == 'SOABI':
-                return 'cpython-35m-darwin'
-            return get_config_var(var)
+        mock_gcf = self.mock_get_config_var(SOABI='cpython-35m-darwin')
 
-        with patch('pip.pep425tags.sysconfig.get_config_var', mock_soabi):
+        with patch('pip.pep425tags.sysconfig.get_config_var', mock_gcf):
             supported = pip.pep425tags.get_supported()
 
         for (py, abi, plat) in supported:
             assert '-' not in py
             assert '-' not in abi
             assert '-' not in plat
 
+    def test_manual_abi_noflags(self):
+        """
+        Test that no flags are set on a non-PyDebug, non-Pymalloc ABI tag.
+        """
+        self.abi_tag_unicode('', {'Py_DEBUG': False, 'WITH_PYMALLOC': False})
+
+    def test_manual_abi_d_flag(self):
+        """
+        Test that the `d` flag is set on a PyDebug, non-Pymalloc ABI tag.
+        """
+        self.abi_tag_unicode('d', {'Py_DEBUG': True, 'WITH_PYMALLOC': False})
+
+    def test_manual_abi_m_flag(self):
+        """
+        Test that the `m` flag is set on a non-PyDebug, Pymalloc ABI tag.
+        """
+        self.abi_tag_unicode('m', {'Py_DEBUG': False, 'WITH_PYMALLOC': True})
+
+    def test_manual_abi_dm_flags(self):
+        """
+        Test that the `dm` flags are set on a PyDebug, Pymalloc ABI tag.
+        """
+        self.abi_tag_unicode('dm', {'Py_DEBUG': True, 'WITH_PYMALLOC': True})
+
 
 class TestMoveWheelFiles(object):
     """