prototype implementation of interpreting PEP725 metadata

grayskull/strategy/py_toml.py

@@ -246,6 +246,52 @@ def add_flit_metadata(metadata: dict, toml_metadata: dict) -> dict:
     return metadata
 
 
+def is_pep725_present(toml_metadata: dict):
+    return 'external' in toml_metadata
+
+
+def get_pep725_mapping(purl: str):
+    '''This function maps a PURL to the name in the conda ecosystem. It is expected
+    that this will be provided on a per-ecosystem basis (such as by conda-forge)'''
+    # taken from
+
+    package_mapping = {
+        'virtual:compiler/c': '${{ compiler("c") }}',
+        'virtual:compiler/cpp': '${{ compiler("cxx") }}',
+        'virtual:compiler/fortran': '${{ compiler("fortran") }}',
+        'virtual:compiler/rust': '${{ compiler("rust") }}',
+        'virtual:interface/blas': '${{ blas }}',
+    }
+    return package_mapping.get(purl) or f'# WARNING: no matching mapping was found for PURL "{purl}". The dependency has been omitted here.'
+
+
+def add_pep725_metadata(metadata: dict, toml_metadata: dict):
+    if not is_pep725_present(toml_metadata):
+        return metadata
+
+    externals = toml_metadata['external']
+    # each of these is a list of PURLs. For each one we find,
+    # we need to map it to the the conda ecosystem
+    requirements = metadata.get('requirements', {})
+    section_map = (
+        ('build', 'build-requires'),
+        ('host', 'host-requires'),
+        ('run', 'dependencies')
+    )
+    for (conda_section, pep725_section) in section_map:
+        requirements[conda_section] = [get_pep725_mapping(purl) for purl in externals.get(pep725_section, [])]
+        # Conda doesn't really have a notion of optional dependencies. We just insert them all.
+        optional_features = toml_metadata.get(f'optional-{pep725_section}', {})
+        for feature_name, feature_deps in optional_features.items():
+            requirements[conda_section].append(f'# OPTIONAL dependencies from feature "{feature_name}"')
+            requirements[conda_section].extend(feature_deps)
+        if not requirements[conda_section]:
+            del requirements[conda_section]
+
+    if requirements:
+        metadata['requirements'] = requirements
+    return metadata
+
 def get_all_toml_info(path_toml: Union[Path, str]) -> dict:
     with open(path_toml, "rb") as f:
         toml_metadata = tomli.load(f)
@@ -288,5 +334,6 @@ def get_all_toml_info(path_toml: Union[Path, str]) -> dict:
 
     add_poetry_metadata(metadata, toml_metadata)
     add_flit_metadata(metadata, toml_metadata)
+    add_pep725_metadata(metadata, toml_metadata)
 
     return metadata

tests/test_poetry.py → tests/test_py_toml.py

@@ -9,6 +9,8 @@
 from grayskull.strategy.py_toml import (
     InvalidVersion,
     add_poetry_metadata,
+    add_flit_metadata,
+    add_pep725_metadata,
     encode_poetry_version,
     get_all_toml_info,
     get_caret_ceiling,
@@ -18,6 +20,14 @@
 )
 
 
+def test_add_flit_metadata():
+    metadata = {"build": {"entry_points": []}}
+    toml_metadata = {"tool": {"flit": {"scripts": {"key": "value"}}}}
+    result = add_flit_metadata(metadata, toml_metadata)
+    assert result == {"build": {"entry_points": ["key = value"]}}
+
+
+
 @pytest.mark.parametrize(
     "version, major, minor, patch",
     [
@@ -160,7 +170,7 @@ def test_poetry_langchain_snapshot(tmpdir):
     assert filecmp.cmp(snapshot_path, output_path, shallow=False)
 
 
-def test_get_constrained_dep_version_not_present():
+def test_poetry_get_constrained_dep_version_not_present():
     assert (
         get_constrained_dep(
             {"git": "https://codeberg.org/hjacobs/pytest-kind.git"}, "pytest-kind"
@@ -169,7 +179,7 @@ def test_get_constrained_dep_version_not_present():
     )
 
 
-def test_entrypoints():
+def test_poetry_entrypoints():
     poetry = {
         "requirements": {"host": ["setuptools"], "run": ["python"]},
         "build": {},
@@ -198,3 +208,27 @@ def test_entrypoints():
         },
         "test": {},
     }
+
+@pytest.mark.parametrize(
+    "conda_section, pep725_section",
+    [
+        ('build', 'build-requires'),
+        ('host', 'host-requires'),
+        ('run', 'dependencies')
+    ])
+@pytest.mark.parametrize(
+    "purl, purl_translated", [
+        ("virtual:compiler/c", '${{ compiler("c") }}'),
+        ("bob", '# WARNING: no matching mapping was found for PURL "bob". The dependency has been omitted here.')
+])
+def test_pep725_section_lookup(conda_section, pep725_section, purl, purl_translated):
+   toml_metadata = {
+        "external": {
+            pep725_section: [purl],
+        }
+   }
+   assert add_pep725_metadata({}, toml_metadata) == {
+        "requirements": {
+            conda_section: [purl_translated]
+        }
+    }