refactor: remove JSON output option

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

src/packaging/metadata.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import builtins
-import dataclasses
 import email.feedparser
 import email.header
 import email.message
@@ -280,35 +279,6 @@ def _get_payload(msg: email.message.Message, source: bytes | str) -> str:
     "version": "version",
 }
 _RAW_TO_EMAIL_MAPPING = {raw: email for email, raw in _EMAIL_TO_RAW_MAPPING.items()}
-_MULTI_FIELDS = {_RAW_TO_EMAIL_MAPPING[x] for x in _LIST_FIELDS | _DICT_FIELDS}
-
-
-@dataclasses.dataclass
-class _JSonMessageSetter:
-    """
-    This provides an API to build a JSON message output in the same way as the
-    classic Message. Line breaks are preserved this way.
-    """
-
-    data: dict[str, str | list[str]]
-
-    def __setitem__(self, name: str, value: str | None) -> None:
-        key = name.replace("-", "_")
-        if value is None:
-            return
-
-        if name == "keywords":
-            values = (x.strip() for x in value.split(","))
-            self.data[key] = [x for x in values if x]
-        elif name in _MULTI_FIELDS:
-            entry = self.data.setdefault(key, [])
-            assert isinstance(entry, list)
-            entry.append(value)
-        else:
-            self.data[key] = value
-
-    def set_payload(self, payload: str) -> None:
-        self["description"] = payload
 
 
 # This class is for writing RFC822 messages
@@ -935,16 +905,7 @@ def as_rfc822(self) -> RFC822Message:
         self._write_metadata(message)
         return message
 
-    def as_json(self) -> dict[str, str | list[str]]:
-        """
-        Return a JSON message with the metadata.
-        """
-        message: dict[str, str | list[str]] = {}
-        smart_message = _JSonMessageSetter(message)
-        self._write_metadata(smart_message)
-        return message
-
-    def _write_metadata(self, message: RFC822Message | _JSonMessageSetter) -> None:
+    def _write_metadata(self, message: RFC822Message) -> None:
         """
         Return an RFC822 message with the metadata.
         """

tests/test_metadata.py

@@ -764,6 +764,7 @@ def test_invalid_license_files(self, license_files):
         with pytest.raises(metadata.InvalidMetadata):
             meta.license_files  # noqa: B018
 
+
 class TestMetadataWriting:
     def test_write_metadata(self):
         meta = metadata.Metadata.from_raw(_RAW_EXAMPLE)
@@ -855,42 +856,6 @@ def test_large(self):
             }
         )
 
-        assert meta.as_json() == {
-            "author": "Example!",
-            "author_email": "Unknown <example@example.com>",
-            "classifier": [
-                "Development Status :: 4 - Beta",
-                "Programming Language :: Python",
-            ],
-            "description": "some readme 👋\n",
-            "description_content_type": "text/markdown",
-            "keywords": ["trampolim", "is", "interesting"],
-            "license": "some license text",
-            "maintainer_email": "Other Example <other@example.com>",
-            "metadata_version": "2.1",
-            "name": "full_metadata",
-            "project_url": [
-                "homepage, example.com",
-                "documentation, readthedocs.org",
-                "repository, github.com/some/repo",
-                "changelog, github.com/some/repo/blob/master/CHANGELOG.rst",
-            ],
-            "provides_extra": ["test"],
-            "requires_dist": [
-                "dependency1",
-                "dependency2>1.0.0",
-                "dependency3[extra]",
-                'dependency4; os_name != "nt"',
-                'dependency5[other-extra]>1.0; os_name == "nt"',
-                'test_dependency; extra == "test"',
-                'test_dependency[test_extra]; extra == "test"',
-                'test_dependency[test_extra2]>3.0; os_name == "nt" and extra == "test"',
-            ],
-            "requires_python": ">=3.8",
-            "summary": "A package with all the metadata :)",
-            "version": "3.2.1",
-        }
-
         core_metadata = meta.as_rfc822()
         assert core_metadata.items() == [
             ("metadata-version", "2.1"),
@@ -928,3 +893,26 @@ def test_large(self):
         ]
 
         assert core_metadata.get_payload() == "some readme 👋\n"
+
+    def test_modern_license(self):
+        meta = metadata.Metadata.from_raw(
+            {
+                "metadata_version": "2.4",
+                "name": "full_metadata",
+                "version": "3.2.1",
+                "license_expression": "MIT",
+                "license_files": ["LICENSE.txt", "LICENSE"],
+            }
+        )
+
+        core_metadata = meta.as_rfc822()
+        assert core_metadata.items() == [
+            ("metadata-version", "2.4"),
+            ("name", "full_metadata"),
+            ("version", "3.2.1"),
+            ("license-expression", "MIT"),
+            ("license-file", "LICENSE.txt"),
+            ("license-file", "LICENSE"),
+        ]
+
+        assert core_metadata.get_payload() is None