utils.link: add PEP 658 (metadata) support (python-poetry#333)

src/poetry/core/packages/utils/link.py

@@ -16,6 +16,7 @@ def __init__(
         url: str,
         comes_from: Any | None = None,
         requires_python: str | None = None,
+        metadata: str | bool | None = None,
     ) -> None:
         """
         Object representing a parsed link from https://pypi.python.org/simple/*
@@ -28,6 +29,11 @@ def __init__(
             String containing the `Requires-Python` metadata field, specified
             in PEP 345. This may be specified by a data-requires-python
             attribute in the HTML link tag, as described in PEP 503.
+        metadata:
+            String of the syntax `<hashname>=<hashvalue>` representing the hash
+            of the Core Metadata file. This may be specified by a
+            data-dist-info-metadata attribute in the HTML link tag, as described
+            in PEP 658.
         """
 
         # url can be a UNC windows share
@@ -38,6 +44,13 @@ def __init__(
         self.comes_from = comes_from
         self.requires_python = requires_python if requires_python else None
 
+        if isinstance(metadata, str):
+            metadata = {"true": True, "": False, "false": False}.get(
+                metadata.strip().lower(), metadata
+            )
+
+        self._metadata = metadata
+
     def __str__(self) -> str:
         if self.requires_python:
             rp = f" (requires-python:{self.requires_python})"
@@ -136,6 +149,34 @@ def subdirectory_fragment(self) -> str | None:
 
     _hash_re = re.compile(r"(sha1|sha224|sha384|sha256|sha512|md5)=([a-f0-9]+)")
 
+    @property
+    def has_metadata(self) -> bool:
+        if self._metadata is None:
+            return False
+        return bool(self._metadata) and (self.is_wheel or self.is_sdist)
+
+    @property
+    def metadata_url(self) -> str | None:
+        if self.has_metadata:
+            return f"{self.url_without_fragment.split('?', 1)[0]}.metadata"
+        return None
+
+    @property
+    def metadata_hash(self) -> str | None:
+        if self.has_metadata and isinstance(self._metadata, str):
+            match = self._hash_re.search(self._metadata)
+            if match:
+                return match.group(2)
+        return None
+
+    @property
+    def metadata_hash_name(self) -> str | None:
+        if self.has_metadata and isinstance(self._metadata, str):
+            match = self._hash_re.search(self._metadata)
+            if match:
+                return match.group(1)
+        return None
+
     @property
     def hash(self) -> str | None:
         match = self._hash_re.search(self.url)

tests/packages/utils/test_utils_link.py

@@ -4,20 +4,117 @@
 
 from hashlib import sha256
 
+import pytest
+
 from poetry.core.packages.utils.link import Link
 
 
-def make_url(ext: str) -> Link:
-    checksum = sha256(str(uuid.uuid4()).encode())
+def make_checksum() -> str:
+    return sha256(str(uuid.uuid4()).encode()).hexdigest()
+
+
+@pytest.fixture()
+def file_checksum() -> str:
+    return make_checksum()
+
+
+@pytest.fixture()
+def metadata_checksum() -> str:
+    return make_checksum()
+
+
+def make_url(
+    ext: str, file_checksum: str | None = None, metadata_checksum: str | None = None
+) -> Link:
+    file_checksum = file_checksum or make_checksum()
     return Link(
         "https://files.pythonhosted.org/packages/16/52/dead/"
-        f"demo-1.0.0.{ext}#sha256={checksum}"
+        f"demo-1.0.0.{ext}#sha256={file_checksum}",
+        metadata=f"sha256={metadata_checksum}" if metadata_checksum else None,
+    )
+
+
+def test_package_link_hash(file_checksum: str) -> None:
+    link = make_url(ext="whl", file_checksum=file_checksum)
+    assert link.hash_name == "sha256"
+    assert link.hash == file_checksum
+    assert link.show_url == "demo-1.0.0.whl"
+
+    # this is legacy PEP 503, no metadata hash is present
+    assert not link.has_metadata
+    assert not link.metadata_url
+    assert not link.metadata_hash
+    assert not link.metadata_hash_name
+
+
+@pytest.mark.parametrize(
+    ("ext", "check"),
+    [
+        ("whl", "wheel"),
+        ("egg", "egg"),
+        ("tar.gz", "sdist"),
+        ("zip", "sdist"),
+        ("cp36-cp36m-manylinux1_x86_64.whl", "wheel"),
+    ],
+)
+def test_package_link_is_checks(ext: str, check: str) -> None:
+    link = make_url(ext=ext)
+    assert getattr(link, f"is_{check}")
+
+
+@pytest.mark.parametrize(
+    ("ext", "has_metadata"),
+    [("whl", True), ("egg", False), ("tar.gz", True), ("zip", True)],
+)
+def test_package_link_pep658(
+    ext: str, has_metadata: bool, metadata_checksum: str
+) -> None:
+    link = make_url(ext=ext, metadata_checksum=metadata_checksum)
+
+    if has_metadata:
+        assert link.has_metadata
+        assert link.metadata_url == f"{link.url_without_fragment}.metadata"
+        assert link.metadata_hash == metadata_checksum
+        assert link.metadata_hash_name == "sha256"
+    else:
+        assert not link.has_metadata
+        assert not link.metadata_url
+        assert not link.metadata_hash
+        assert not link.metadata_hash_name
+
+
+def test_package_link_pep658_no_default_metadata() -> None:
+    link = make_url(ext="whl")
+
+    assert not link.has_metadata
+    assert not link.metadata_url
+    assert not link.metadata_hash
+    assert not link.metadata_hash_name
+
+
+@pytest.mark.parametrize(
+    ("metadata", "has_metadata"),
+    [
+        ("true", True),
+        ("false", False),
+        ("", False),
+    ],
+)
+def test_package_link_pep653_non_hash_metadata_value(
+    file_checksum: str, metadata: str | bool, has_metadata: bool
+) -> None:
+    link = Link(
+        "https://files.pythonhosted.org/packages/16/52/dead/"
+        f"demo-1.0.0.whl#sha256={file_checksum}",
+        metadata=metadata,
     )
 
+    if has_metadata:
+        assert link.has_metadata
+        assert link.metadata_url == f"{link.url_without_fragment}.metadata"
+    else:
+        assert not link.has_metadata
+        assert not link.metadata_url
 
-def test_package_link_is_checks() -> None:
-    assert make_url("egg").is_egg
-    assert make_url("tar.gz").is_sdist
-    assert make_url("zip").is_sdist
-    assert make_url("exe").is_wininst
-    assert make_url("cp36-cp36m-manylinux1_x86_64.whl").is_wheel
+    assert not link.metadata_hash
+    assert not link.metadata_hash_name