refactor: prepare for EmailMessage

README.md

@@ -30,7 +30,7 @@ metadata = StandardMetadata.from_pyproject(parsed_pyproject, allow_extra_keys =
 print(metadata.entrypoints)  # same fields as defined in PEP 621
 
 pkg_info = metadata.as_rfc822()
-print(str(pkg_info))  # core metadata
+print(bytes(pkg_info).decode("utf-8"))  # core metadata
 ```
 
 

pyproject_metadata/__init__.py

@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-import collections
 import copy
 import dataclasses
 import email.utils
@@ -117,35 +116,44 @@ class ConfigurationWarning(UserWarning):
 class RFC822Message:
     """Python-flavored RFC 822 message implementation."""
 
+    __slots__ = ('_headers', '_body')
+
     def __init__(self) -> None:
-        self.headers: collections.OrderedDict[str, list[str]] = (
-            collections.OrderedDict()
-        )
-        self.body: str | None = None
+        self._headers: list[tuple[str, str]] = []
+        self._body: str | None = None
+
+    def items(self) -> list[tuple[str, str]]:
+        return self._headers.copy()
+
+    def get_all(self, name: str) -> None | list[str]:
+        return [v for k, v in self.items() if k == name]
 
     def __setitem__(self, name: str, value: str | None) -> None:
         if not value:
             return
-        if name not in self.headers:
-            self.headers[name] = []
-        self.headers[name].append(value)
+        self._headers.append((name, value))
 
     def __str__(self) -> str:
         text = ''
-        for name, entries in self.headers.items():
-            for entry in entries:
-                lines = entry.strip('\n').split('\n')
-                text += f'{name}: {lines[0]}\n'
-                for line in lines[1:]:
-                    text += ' ' * 8 + line + '\n'
+        for name, entry in self.items():
+            lines = entry.strip('\n').split('\n')
+            text += f'{name}: {lines[0]}\n'
+            for line in lines[1:]:
+                text += ' ' * 8 + line + '\n'
         text += '\n'
-        if self.body:
-            text += self.body
+        if self._body:
+            text += self._body
         return text
 
     def __bytes__(self) -> bytes:
         return str(self).encode()
 
+    def get_payload(self) -> str | None:
+        return self._body
+
+    def set_payload(self, body: str) -> None:
+        self._body = body
+
 
 class DataFetcher:
     def __init__(self, data: Mapping[str, Any]) -> None:
@@ -603,7 +611,7 @@ def write_to_rfc822(self, message: RFC822Message) -> None:  # noqa: C901
         if self.readme:
             if self.readme.content_type:
                 message['Description-Content-Type'] = self.readme.content_type
-            message.body = self.readme.text
+            message.set_payload(self.readme.text)
         # Core Metadata 2.2
         if self.metadata_version != '2.1':
             for field in self.dynamic:

tests/test_rfc822.py

@@ -73,9 +73,9 @@
             ],
             """\
             ItemA: ValueA1
-            ItemA: ValueA2
             ItemB: ValueB
             ItemC: ValueC
+            ItemA: ValueA2
             """,
         ),
         (
@@ -112,7 +112,8 @@ def test_body() -> None:
     message['ItemB'] = 'ValueB'
     message['ItemC'] = 'ValueC'
 
-    message.body = textwrap.dedent("""
+    message.set_payload(
+        textwrap.dedent("""
         Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris congue semper
         fermentum. Nunc vitae tempor ante. Aenean aliquet posuere lacus non faucibus.
         In porttitor congue luctus. Vivamus eu dignissim orci. Donec egestas mi ac
@@ -126,6 +127,7 @@ def test_body() -> None:
         finibus nulla. Donec sit amet ante in neque pulvinar faucibus sed nec justo.
         Fusce hendrerit massa libero, sit amet pulvinar magna tempor quis.
     """)
+    )
 
     assert str(message) == textwrap.dedent("""\
         ItemA: ValueA
@@ -164,7 +166,7 @@ def test_convert_optional_dependencies() -> None:
         }
     )
     message = metadata.as_rfc822()
-    requires = message.headers['Requires-Dist']
+    requires = message.get_all('Requires-Dist')
     assert requires == [
         'foo; (os_name == "nt" or sys_platform == "win32") and extra == "test"',
         'bar; os_name == "posix" and sys_platform == "linux" and extra == "test"',
@@ -191,6 +193,6 @@ def test_convert_author_email() -> None:
         }
     )
     message = metadata.as_rfc822()
-    assert message.headers['Author-Email'] == [
+    assert message.get_all('Author-Email') == [
         '"John Doe, Inc." <[email protected]>, "Kate Doe, LLC." <[email protected]>'
     ]

tests/test_standard_metadata.py

@@ -713,42 +713,39 @@ def test_as_rfc822(monkeypatch: pytest.MonkeyPatch) -> None:
     with open('pyproject.toml', 'rb') as f:
         metadata = pyproject_metadata.StandardMetadata.from_pyproject(tomllib.load(f))
     core_metadata = metadata.as_rfc822()
-    assert core_metadata.headers == {
-        'Metadata-Version': ['2.1'],
-        'Name': ['full_metadata'],
-        'Summary': ['A package with all the metadata :)'],
-        'Version': ['3.2.1'],
-        'Keywords': ['trampolim,is,interesting'],
-        'Home-page': ['example.com'],
-        'Author': ['Example!'],
-        'Author-Email': ['Unknown <[email protected]>'],
-        'Maintainer-Email': ['Other Example <[email protected]>'],
-        'License': ['some license text'],
-        'Classifier': [
-            'Development Status :: 4 - Beta',
-            'Programming Language :: Python',
-        ],
-        'Project-URL': [
-            'Homepage, example.com',
-            'Documentation, readthedocs.org',
-            'Repository, github.com/some/repo',
-            'Changelog, github.com/some/repo/blob/master/CHANGELOG.rst',
-        ],
-        'Requires-Python': ['>=3.8'],
-        '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"',
+    assert core_metadata.items() == [
+        ('Metadata-Version', '2.1'),
+        ('Name', 'full_metadata'),
+        ('Version', '3.2.1'),
+        ('Summary', 'A package with all the metadata :)'),
+        ('Keywords', 'trampolim,is,interesting'),
+        ('Home-page', 'example.com'),
+        ('Author', 'Example!'),
+        ('Author-Email', 'Unknown <[email protected]>'),
+        ('Maintainer-Email', 'Other Example <[email protected]>'),
+        ('License', 'some license text'),
+        ('Classifier', 'Development Status :: 4 - Beta'),
+        ('Classifier', 'Programming Language :: Python'),
+        ('Project-URL', 'Homepage, example.com'),
+        ('Project-URL', 'Documentation, readthedocs.org'),
+        ('Project-URL', 'Repository, github.com/some/repo'),
+        ('Project-URL', 'Changelog, github.com/some/repo/blob/master/CHANGELOG.rst'),
+        ('Requires-Python', '>=3.8'),
+        ('Requires-Dist', 'dependency1'),
+        ('Requires-Dist', 'dependency2>1.0.0'),
+        ('Requires-Dist', 'dependency3[extra]'),
+        ('Requires-Dist', 'dependency4; os_name != "nt"'),
+        ('Requires-Dist', 'dependency5[other-extra]>1.0; os_name == "nt"'),
+        ('Provides-Extra', 'test'),
+        ('Requires-Dist', 'test_dependency; extra == "test"'),
+        ('Requires-Dist', 'test_dependency[test_extra]; extra == "test"'),
+        (
+            'Requires-Dist',
             'test_dependency[test_extra2]>3.0; os_name == "nt" and extra == "test"',
-        ],
-        'Description-Content-Type': ['text/markdown'],
-    }
-    assert core_metadata.body == 'some readme 👋\n'
+        ),
+        ('Description-Content-Type', 'text/markdown'),
+    ]
+    assert core_metadata.get_payload() == 'some readme 👋\n'
 
 
 def test_as_rfc822_dynamic(monkeypatch: pytest.MonkeyPatch) -> None:
@@ -757,12 +754,12 @@ def test_as_rfc822_dynamic(monkeypatch: pytest.MonkeyPatch) -> None:
     with open('pyproject.toml', 'rb') as f:
         metadata = pyproject_metadata.StandardMetadata.from_pyproject(tomllib.load(f))
     core_metadata = metadata.as_rfc822()
-    assert dict(core_metadata.headers) == {
-        'Metadata-Version': ['2.2'],
-        'Name': ['dynamic-description'],
-        'Version': ['1.0.0'],
-        'Dynamic': ['description'],
-    }
+    assert core_metadata.items() == [
+        ('Metadata-Version', '2.2'),
+        ('Name', 'dynamic-description'),
+        ('Version', '1.0.0'),
+        ('Dynamic', 'description'),
+    ]
 
 
 @pytest.mark.parametrize('metadata_version', ['2.1', '2.2', '2.3'])
@@ -784,7 +781,7 @@ def test_as_rfc822_set_metadata(metadata_version: str) -> None:
     )
     assert metadata.metadata_version == metadata_version
 
-    rfc822 = str(metadata.as_rfc822())
+    rfc822 = bytes(metadata.as_rfc822()).decode('utf-8')
 
     assert f'Metadata-Version: {metadata_version}' in rfc822