Add test capturing expectation when metadata is not the common case.

Author: jaraco

tests/fixtures.py

@@ -1,5 +1,6 @@
 import os
 import sys
+import copy
 import shutil
 import pathlib
 import tempfile
@@ -108,6 +109,16 @@ def setUp(self):
         super(DistInfoPkg, self).setUp()
         build_files(DistInfoPkg.files, self.site_dir)
 
+    def make_uppercase(self):
+        """
+        Rewrite metadata with everything uppercase.
+        """
+        shutil.rmtree(self.site_dir / "distinfo_pkg-1.0.0.dist-info")
+        files = copy.deepcopy(DistInfoPkg.files)
+        info = files["distinfo_pkg-1.0.0.dist-info"]
+        info["METADATA"] = info["METADATA"].upper()
+        build_files(files, self.site_dir)
+
 
 class DistInfoPkgWithDot(OnSysPath, SiteDir):
     files: FilesDef = {

tests/test_api.py

@@ -262,6 +262,13 @@ def test_as_json_egg_info(self):
         assert desc.startswith('Once upon a time\nThere was')
         assert len(md['classifier']) == 2
 
+    def test_as_json_odd_case(self):
+        self.make_uppercase()
+        md = metadata('distinfo-pkg').json
+        assert 'name' in md
+        assert len(md['requires_dist']) == 2
+        assert md['keywords'] == ['SAMPLE', 'PACKAGE']
+
 
 class LegacyDots(fixtures.DistInfoPkgWithDotLegacy, unittest.TestCase):
     def test_name_normalization(self):