New resolver config

src/fromager/packagesettings/__init__.py

@@ -28,6 +28,7 @@
     PyPIGitResolver,
     PyPIPrebuiltResolver,
     PyPISDistResolver,
+    SourceResolver,
     pep440_tag_matcher,
 )
 from ._settings import Settings, SettingsFile
@@ -84,6 +85,7 @@
     "SbomSettings",
     "Settings",
     "SettingsFile",
+    "SourceResolver",
     "Template",
     "Variant",
     "VariantChangelog",

src/fromager/packagesettings/_models.py

@@ -16,7 +16,7 @@
 from pydantic import AnyUrl, Field, PrivateAttr, StringConstraints
 from pydantic_core import core_schema
 
-# from ._resolver import SourceResolver
+from ._resolver import SourceResolver
 from ._typedefs import (
     MODEL_CONFIG,
     BuildDirectory,
@@ -480,9 +480,23 @@ class VariantInfo(pydantic.BaseModel):
     pre_built: bool = False
     """Use pre-built wheel from index server?"""
 
-    # TODO
-    # source: SourceResolver | None
-    # """Source resolver and downloader"""
+    source: SourceResolver | None = None
+    """Source resolver and downloader"""
+
+    @pydantic.model_validator(mode="after")
+    def validate_source_exclusivity(self) -> typing.Self:
+        """Validate that ``source`` is mutually exclusive with legacy fields."""
+        if self.source is None:
+            return self
+        legacy_fields = {"wheel_server_url", "pre_built"}
+        conflicts = legacy_fields & self.model_fields_set
+        if conflicts:
+            raise ValueError(
+                f"'source' is mutually exclusive with legacy settings: "
+                f"{sorted(conflicts)}. Use 'source' alone or remove it "
+                f"and use the legacy settings."
+            )
+        return self
 
 
 class GitOptions(pydantic.BaseModel):
@@ -608,9 +622,8 @@ class PackageSettings(pydantic.BaseModel):
     project_override: ProjectOverride = Field(default_factory=ProjectOverride)
     """Patch project settings"""
 
-    # TODO
-    # source: SourceResolver | None
-    # """Source resolver and downloader"""
+    source: SourceResolver | None = None
+    """Source resolver and downloader"""
 
     variants: Mapping[Variant, VariantInfo] = Field(default_factory=dict)
     """Variant configuration"""
@@ -626,6 +639,21 @@ def before_none_dict(
             v = {}
         return v
 
+    @pydantic.model_validator(mode="after")
+    def validate_source_exclusivity(self) -> typing.Self:
+        """Validate that ``source`` is mutually exclusive with legacy fields."""
+        if self.source is None:
+            return self
+        legacy_fields = {"download_source", "resolver_dist"}
+        conflicts = legacy_fields & self.model_fields_set
+        if conflicts:
+            raise ValueError(
+                f"'source' is mutually exclusive with legacy settings: "
+                f"{sorted(conflicts)}. Use 'source' alone or remove it "
+                f"and use the legacy settings."
+            )
+        return self
+
     @classmethod
     def from_mapping(
         cls,

src/fromager/packagesettings/_pbi.py

@@ -26,6 +26,7 @@
 
 if typing.TYPE_CHECKING:
     from .. import build_environment
+    from ._resolver import SourceResolver
     from ._settings import Settings
 
 logger = logging.getLogger(__name__)
@@ -176,6 +177,19 @@ def wheel_server_url(self) -> str | None:
             return str(vi.wheel_server_url)
         return None
 
+    @property
+    def source_resolver(self) -> SourceResolver | None:
+        """Source resolver for the package variant.
+
+        Returns the variant-level source resolver if configured,
+        otherwise falls back to the package-level source resolver,
+        or ``None`` if neither is set.
+        """
+        vi = self._ps.variants.get(self.variant)
+        if vi is not None and vi.source is not None:
+            return vi.source
+        return self._ps.source
+
     @property
     def override_module_name(self) -> str:
         """Override module name from package name"""

tests/test_packagesettings.py

@@ -18,9 +18,12 @@
     Package,
     PackageBuildInfo,
     PackageSettings,
+    PyPIPrebuiltResolver,
+    PyPISDistResolver,
     ResolverDist,
     Settings,
     SettingsFile,
+    SourceResolver,
     Variant,
     substitute_template,
 )
@@ -90,6 +93,7 @@
         "use_pypi_org_metadata": True,
         "min_release_age": None,
     },
+    "source": None,
     "variants": {
         "cpu": {
             "annotations": {
@@ -98,6 +102,7 @@
             "env": {"EGG": "spam ${EGG}", "EGG_AGAIN": "$EGG"},
             "wheel_server_url": "https://wheel.test/simple",
             "pre_built": False,
+            "source": None,
         },
         "rocm": {
             "annotations": {
@@ -106,12 +111,14 @@
             "env": {"SPAM": ""},
             "wheel_server_url": None,
             "pre_built": True,
+            "source": None,
         },
         "cuda": {
             "annotations": None,
             "env": {},
             "wheel_server_url": None,
             "pre_built": False,
+            "source": None,
         },
     },
 }
@@ -152,6 +159,7 @@
         "use_pypi_org_metadata": None,
         "min_release_age": None,
     },
+    "source": None,
     "variants": {},
 }
 
@@ -193,11 +201,13 @@
         "use_pypi_org_metadata": None,
         "min_release_age": None,
     },
+    "source": None,
     "variants": {
         "cpu": {
             "annotations": None,
             "env": {},
             "pre_built": True,
+            "source": None,
             "wheel_server_url": None,
         },
     },
@@ -1152,3 +1162,190 @@ def test_filter_env(
 ) -> None:
     ec = ExternalCommands(keep_env=keep, delete_env=delete)
     assert ec.filter_env(env) == expected
+
+
+# -- source field and source_resolver PBI property ----------------------------
+
+
+def test_source_resolver_importable() -> None:
+    """``SourceResolver`` is importable from ``fromager.packagesettings``."""
+    args = typing.get_args(SourceResolver)
+    assert len(args) == 2
+    union_members = typing.get_args(args[0])
+    assert PyPISDistResolver in union_members
+    assert PyPIPrebuiltResolver in union_members
+
+
+def test_package_settings_with_source() -> None:
+    """``PackageSettings`` loads YAML with ``source:`` correctly."""
+    yaml_str = "source:\n  provider: pypi-sdist\n"
+    ps = PackageSettings.from_string("test-source-pkg", yaml_str)
+    assert ps.source is not None
+    assert isinstance(ps.source, PyPISDistResolver)
+    assert ps.source.provider == "pypi-sdist"
+
+
+def test_variant_info_with_source() -> None:
+    """``VariantInfo`` with ``source:`` works."""
+    yaml_str = "variants:\n  cpu:\n    source:\n      provider: pypi-prebuilt\n"
+    ps = PackageSettings.from_string("test-variant-source-pkg", yaml_str)
+    vi = ps.variants[Variant("cpu")]
+    assert vi.source is not None
+    assert isinstance(vi.source, PyPIPrebuiltResolver)
+
+
+def test_package_settings_without_source() -> None:
+    """``PackageSettings`` without ``source:`` has ``source=None``."""
+    ps = PackageSettings.from_default("test-pkg")
+    assert ps.source is None
+
+
+def test_pbi_source_resolver_none(tmp_path: pathlib.Path) -> None:
+    """``pbi.source_resolver`` returns ``None`` when no source configured."""
+    ps = PackageSettings.from_default("test-pkg")
+    settings = Settings(
+        settings=SettingsFile(),
+        package_settings=[ps],
+        variant="cpu",
+        patches_dir=tmp_path,
+        max_jobs=1,
+    )
+    pbi = settings.package_build_info("test-pkg")
+    assert pbi.source_resolver is None
+
+
+def test_pbi_source_resolver_package_level(tmp_path: pathlib.Path) -> None:
+    """``pbi.source_resolver`` returns package-level source."""
+    yaml_str = "source:\n  provider: pypi-sdist\n"
+    ps = PackageSettings.from_string("test-pkg", yaml_str)
+    settings = Settings(
+        settings=SettingsFile(),
+        package_settings=[ps],
+        variant="cpu",
+        patches_dir=tmp_path,
+        max_jobs=1,
+    )
+    pbi = settings.package_build_info("test-pkg")
+    assert pbi.source_resolver is not None
+    assert isinstance(pbi.source_resolver, PyPISDistResolver)
+
+
+def test_pbi_source_resolver_variant_overrides_package(
+    tmp_path: pathlib.Path,
+) -> None:
+    """``pbi.source_resolver`` returns variant source over package source."""
+    yaml_str = (
+        "source:\n"
+        "  provider: pypi-sdist\n"
+        "variants:\n"
+        "  cpu:\n"
+        "    source:\n"
+        "      provider: pypi-prebuilt\n"
+    )
+    ps = PackageSettings.from_string("test-pkg", yaml_str)
+    settings = Settings(
+        settings=SettingsFile(),
+        package_settings=[ps],
+        variant="cpu",
+        patches_dir=tmp_path,
+        max_jobs=1,
+    )
+    pbi = settings.package_build_info("test-pkg")
+    assert isinstance(pbi.source_resolver, PyPIPrebuiltResolver)
+
+
+# -- source vs legacy mutual exclusivity validation --------------------------
+
+
+@pytest.mark.parametrize(
+    "yaml_str",
+    [
+        pytest.param(
+            "source:\n  provider: pypi-sdist\n"
+            "download_source:\n  url: https://egg.test/pkg-${version}.tar.gz\n",
+            id="source-with-download-source",
+        ),
+        pytest.param(
+            "source:\n  provider: pypi-sdist\n"
+            "resolver_dist:\n  sdist_server_url: https://sdist.test/simple\n",
+            id="source-with-resolver-dist",
+        ),
+        pytest.param(
+            "source:\n  provider: pypi-sdist\n"
+            "download_source:\n  url: https://egg.test/pkg.tar.gz\n"
+            "resolver_dist:\n  sdist_server_url: https://sdist.test/simple\n",
+            id="source-with-both-legacy-fields",
+        ),
+        pytest.param(
+            "source:\n  provider: pypi-sdist\ndownload_source:\n",
+            id="source-with-empty-download-source",
+        ),
+    ],
+)
+def test_package_source_exclusivity_invalid(yaml_str: str) -> None:
+    """Setting ``source`` alongside legacy package fields raises."""
+    with pytest.raises(RuntimeError, match="mutually exclusive"):
+        PackageSettings.from_string("conflict-pkg", yaml_str)
+
+
+@pytest.mark.parametrize(
+    "yaml_str",
+    [
+        pytest.param(
+            "variants:\n  cpu:\n    source:\n      provider: pypi-prebuilt\n"
+            "    wheel_server_url: https://wheel.test/simple\n",
+            id="source-with-wheel-server-url",
+        ),
+        pytest.param(
+            "variants:\n  cpu:\n    source:\n      provider: pypi-prebuilt\n"
+            "    pre_built: true\n",
+            id="source-with-pre-built",
+        ),
+    ],
+)
+def test_variant_source_exclusivity_invalid(yaml_str: str) -> None:
+    """Setting ``source`` alongside legacy variant fields raises."""
+    with pytest.raises(RuntimeError, match="mutually exclusive"):
+        PackageSettings.from_string("conflict-pkg", yaml_str)
+
+
+def test_legacy_only_config_valid() -> None:
+    """Legacy-only config loads without error."""
+    yaml_str = (
+        "download_source:\n  url: https://egg.test/pkg-${version}.tar.gz\n"
+        "resolver_dist:\n  sdist_server_url: https://sdist.test/simple\n"
+    )
+    ps = PackageSettings.from_string("legacy-pkg", yaml_str)
+    assert ps.source is None
+    assert ps.download_source.url is not None
+
+
+def test_source_only_config_valid() -> None:
+    """Source-only config loads without error."""
+    yaml_str = "source:\n  provider: pypi-sdist\n"
+    ps = PackageSettings.from_string("new-pkg", yaml_str)
+    assert ps.source is not None
+    assert ps.download_source.url is None
+
+
+def test_variant_legacy_only_valid() -> None:
+    """Variant with only legacy fields loads without error."""
+    yaml_str = "variants:\n  cpu:\n    pre_built: true\n    wheel_server_url: https://wheel.test/simple\n"
+    ps = PackageSettings.from_string("legacy-variant-pkg", yaml_str)
+    vi = ps.variants[Variant("cpu")]
+    assert vi.source is None
+    assert vi.pre_built is True
+
+
+def test_source_exclusivity_error_lists_fields() -> None:
+    """Error message includes the specific conflicting field names."""
+    yaml_str = (
+        "source:\n  provider: pypi-sdist\n"
+        "download_source:\n  url: https://egg.test/a.tar.gz\n"
+        "resolver_dist:\n  sdist_server_url: https://sdist.test\n"
+    )
+    with pytest.raises(RuntimeError) as exc_info:
+        PackageSettings.from_string("conflict-pkg", yaml_str)
+    error_str = str(exc_info.value)
+    assert "download_source" in error_str
+    assert "resolver_dist" in error_str