_python_requirements_file target uses source: str field instead o…

…f `sources: list[str]` (pantsbuild#14082)

To minimize behavior changes while implementing pantsbuild#14075, we want to make sure that `--changed-since=HEAD --changed-dependees=direct` will still claim that all generated `python_requirement` targets are impacted if the `requirements.txt` changed.

This would happen naturally if a generated target depended on its target generator: pantsbuild#13118. But that will require a lot more design work and is a big change we're not ready to make.

So we can work around this by still having `_python_requirements_file` even with target generators. But before doing that, we should change to `source: str` to actually represent the expected API of the target.

Because this is a private API, we make a breaking change.

[ci skip-rust]
[ci skip-build-wheels]

src/python/pants/backend/python/dependency_inference/rules_test.py

@@ -19,7 +19,7 @@
 )
 from pants.backend.python.macros.python_requirements_caof import PythonRequirementsCAOF
 from pants.backend.python.target_types import (
-    PythonRequirementsFile,
+    PythonRequirementsFileTarget,
     PythonRequirementTarget,
     PythonSourceField,
     PythonSourcesGeneratorTarget,
@@ -265,7 +265,7 @@ def test_infer_python_strict(caplog) -> None:
         target_types=[
             PythonSourcesGeneratorTarget,
             PythonRequirementTarget,
-            PythonRequirementsFile,
+            PythonRequirementsFileTarget,
         ],
         context_aware_object_factories={"python_requirements": PythonRequirementsCAOF},
     )

src/python/pants/backend/python/macros/deprecation_fixers.py

@@ -8,7 +8,7 @@
 import tokenize
 from dataclasses import dataclass
 
-from pants.backend.python.target_types import PythonRequirementsFile, PythonRequirementTarget
+from pants.backend.python.target_types import PythonRequirementsFileTarget, PythonRequirementTarget
 from pants.build_graph.address import InvalidAddress
 from pants.core.goals.update_build_files import (
     DeprecationFixerRequest,
@@ -22,7 +22,7 @@
     Dependencies,
     DependenciesRequest,
     ExplicitlyProvidedDependencies,
-    MultipleSourcesField,
+    SingleSourceField,
     UnexpandedTargets,
 )
 from pants.engine.unions import UnionRule
@@ -83,13 +83,13 @@ async def determine_macro_changes(all_targets: AllTargets) -> MacroRenames:
     for python_req_deps_field, build_file_addr, deps in zip(
         python_requirement_dependencies_fields, build_file_addresses_per_tgt, deps_per_tgt
     ):
-        generator_tgt = next((tgt for tgt in deps if isinstance(tgt, PythonRequirementsFile)), None)
+        generator_tgt = next(
+            (tgt for tgt in deps if isinstance(tgt, PythonRequirementsFileTarget)), None
+        )
         if generator_tgt is None:
             continue
 
-        # Assume there is a single source. We should have changed this target to use
-        # `SingleSourceField`, alas.
-        generator_source = generator_tgt[MultipleSourcesField].value[0]  # type: ignore[index]
+        generator_source = generator_tgt[SingleSourceField].value
         if "Pipfile" in generator_source:
             generator_alias = "pipenv_requirements"
         elif "pyproject.toml" in generator_source:

src/python/pants/backend/python/macros/deprecation_fixers_test.py

@@ -17,7 +17,7 @@
 from pants.backend.python.macros.pipenv_requirements_caof import PipenvRequirementsCAOF
 from pants.backend.python.macros.poetry_requirements_caof import PoetryRequirementsCAOF
 from pants.backend.python.macros.python_requirements_caof import PythonRequirementsCAOF
-from pants.backend.python.target_types import PythonRequirementsFile, PythonRequirementTarget
+from pants.backend.python.target_types import PythonRequirementsFileTarget, PythonRequirementTarget
 from pants.core.goals.update_build_files import RewrittenBuildFile
 from pants.core.target_types import GenericTarget
 from pants.engine.addresses import Address
@@ -33,7 +33,7 @@ def rule_runner() -> RuleRunner:
             QueryRule(MacroRenames, []),
             QueryRule(RewrittenBuildFile, [UpdatePythonMacrosRequest]),
         ),
-        target_types=[GenericTarget, PythonRequirementsFile, PythonRequirementTarget],
+        target_types=[GenericTarget, PythonRequirementsFileTarget, PythonRequirementTarget],
         context_aware_object_factories={
             "python_requirements": PythonRequirementsCAOF,
             "poetry_requirements": PoetryRequirementsCAOF,

src/python/pants/backend/python/macros/pipenv_requirements_caof.py

@@ -66,7 +66,7 @@ def __call__(
             self._parse_context.create_object(
                 "_python_requirements_file",
                 name=requirements_file_target_name,
-                sources=[source],
+                source=source,
             )
             requirements_dep = f":{requirements_file_target_name}"
 

src/python/pants/backend/python/macros/pipenv_requirements_caof_test.py

@@ -9,7 +9,7 @@
 
 from pants.backend.python.macros.pipenv_requirements_caof import PipenvRequirementsCAOF
 from pants.backend.python.pip_requirement import PipRequirement
-from pants.backend.python.target_types import PythonRequirementsFile, PythonRequirementTarget
+from pants.backend.python.target_types import PythonRequirementsFileTarget, PythonRequirementTarget
 from pants.engine.addresses import Address
 from pants.engine.target import AllTargets
 from pants.testutil.rule_runner import RuleRunner
@@ -18,7 +18,7 @@
 @pytest.fixture
 def rule_runner() -> RuleRunner:
     return RuleRunner(
-        target_types=[PythonRequirementTarget, PythonRequirementsFile],
+        target_types=[PythonRequirementTarget, PythonRequirementsFileTarget],
         context_aware_object_factories={"pipenv_requirements": PipenvRequirementsCAOF},
     )
 
@@ -28,7 +28,7 @@ def assert_pipenv_requirements(
     build_file_entry: str,
     pipfile_lock: dict,
     *,
-    expected_file_dep: PythonRequirementsFile,
+    expected_file_dep: PythonRequirementsFileTarget,
     expected_targets: Iterable[PythonRequirementTarget],
     pipfile_lock_relpath: str = "Pipfile.lock",
 ) -> None:
@@ -53,8 +53,8 @@ def test_pipfile_lock(rule_runner: RuleRunner) -> None:
             "default": {"ansicolors": {"version": ">=1.18.0"}},
             "develop": {"cachetools": {"markers": "python_version ~= '3.5'", "version": "==4.1.1"}},
         },
-        expected_file_dep=PythonRequirementsFile(
-            {"sources": ["Pipfile.lock"]}, Address("", target_name="Pipfile.lock")
+        expected_file_dep=PythonRequirementsFileTarget(
+            {"source": "Pipfile.lock"}, Address("", target_name="Pipfile.lock")
         ),
         expected_targets=[
             PythonRequirementTarget(
@@ -93,8 +93,8 @@ def test_properly_creates_extras_requirements(rule_runner: RuleRunner) -> None:
                 }
             },
         },
-        expected_file_dep=PythonRequirementsFile(
-            {"sources": ["Pipfile.lock"]}, Address("", target_name="Pipfile.lock")
+        expected_file_dep=PythonRequirementsFileTarget(
+            {"source": "Pipfile.lock"}, Address("", target_name="Pipfile.lock")
         ),
         expected_targets=[
             PythonRequirementTarget(
@@ -132,13 +132,13 @@ def test_supply_python_requirements_file(rule_runner: RuleRunner) -> None:
 
             _python_requirements_file(
                 name='custom_pipfile_target',
-                sources=['custom/pipfile/Pipfile.lock']
+                source='custom/pipfile/Pipfile.lock'
             )
             """
         ),
         {"default": {"ansicolors": {"version": ">=1.18.0"}}},
-        expected_file_dep=PythonRequirementsFile(
-            {"sources": ["custom/pipfile/Pipfile.lock"]},
+        expected_file_dep=PythonRequirementsFileTarget(
+            {"source": "custom/pipfile/Pipfile.lock"},
             Address("", target_name="custom_pipfile_target"),
         ),
         expected_targets=[

src/python/pants/backend/python/macros/poetry_requirements_caof.py

@@ -409,7 +409,7 @@ def __call__(
         req_file_tgt = self._parse_context.create_object(
             "_python_requirements_file",
             name=source.replace(os.path.sep, "_"),
-            sources=[source],
+            source=source,
         )
         requirements_dep = f":{req_file_tgt.name}"
 

src/python/pants/backend/python/macros/poetry_requirements_caof_test.py

@@ -23,7 +23,7 @@
     parse_str_version,
 )
 from pants.backend.python.pip_requirement import PipRequirement
-from pants.backend.python.target_types import PythonRequirementsFile, PythonRequirementTarget
+from pants.backend.python.target_types import PythonRequirementsFileTarget, PythonRequirementTarget
 from pants.engine.addresses import Address
 from pants.engine.internals.scheduler import ExecutionError
 from pants.engine.target import AllTargets
@@ -391,7 +391,7 @@ def test_parse_multi_reqs() -> None:
 @pytest.fixture
 def rule_runner() -> RuleRunner:
     return RuleRunner(
-        target_types=[PythonRequirementTarget, PythonRequirementsFile],
+        target_types=[PythonRequirementTarget, PythonRequirementsFileTarget],
         context_aware_object_factories={"poetry_requirements": PoetryRequirementsCAOF},
     )
 
@@ -401,7 +401,7 @@ def assert_poetry_requirements(
     build_file_entry: str,
     pyproject_toml: str,
     *,
-    expected_file_dep: PythonRequirementsFile,
+    expected_file_dep: PythonRequirementsFileTarget,
     expected_targets: Iterable[PythonRequirementTarget],
     pyproject_toml_relpath: str = "pyproject.toml",
 ) -> None:
@@ -438,8 +438,8 @@ def test_pyproject_toml(rule_runner: RuleRunner) -> None:
             ansicolors = ">=1.18.0"
             """
         ),
-        expected_file_dep=PythonRequirementsFile(
-            {"sources": ["pyproject.toml"]},
+        expected_file_dep=PythonRequirementsFileTarget(
+            {"source": "pyproject.toml"},
             address=Address("", target_name="pyproject.toml"),
         ),
         expected_targets=[
@@ -489,8 +489,8 @@ def test_source_override(rule_runner: RuleRunner) -> None:
             """
         ),
         pyproject_toml_relpath="subdir/pyproject.toml",
-        expected_file_dep=PythonRequirementsFile(
-            {"sources": ["subdir/pyproject.toml"]},
+        expected_file_dep=PythonRequirementsFileTarget(
+            {"source": "subdir/pyproject.toml"},
             address=Address("", target_name="subdir_pyproject.toml"),
         ),
         expected_targets=[
@@ -515,8 +515,8 @@ def test_non_pep440_error(rule_runner: RuleRunner, caplog: Any) -> None:
             foo = "~r62b"
             [tool.poetry.dev-dependencies]
             """,
-            expected_file_dep=PythonRequirementsFile(
-                {"sources": ["pyproject.toml"]},
+            expected_file_dep=PythonRequirementsFileTarget(
+                {"source": "pyproject.toml"},
                 address=Address("", target_name="pyproject.toml"),
             ),
             expected_targets=[],
@@ -532,8 +532,8 @@ def test_no_req_defined_warning(rule_runner: RuleRunner, caplog: Any) -> None:
         [tool.poetry.dependencies]
         [tool.poetry.dev-dependencies]
         """,
-        expected_file_dep=PythonRequirementsFile(
-            {"sources": ["pyproject.toml"]},
+        expected_file_dep=PythonRequirementsFileTarget(
+            {"source": "pyproject.toml"},
             address=Address("", target_name="pyproject.toml"),
         ),
         expected_targets=[],
@@ -551,8 +551,8 @@ def test_bad_dict_format(rule_runner: RuleRunner) -> None:
             foo = {bad_req = "test"}
             [tool.poetry.dev-dependencies]
             """,
-            expected_file_dep=PythonRequirementsFile(
-                {"sources": ["pyproject.toml"]},
+            expected_file_dep=PythonRequirementsFileTarget(
+                {"source": "pyproject.toml"},
                 address=Address("", target_name="pyproject.toml"),
             ),
             expected_targets=[],
@@ -570,8 +570,8 @@ def test_bad_req_type(rule_runner: RuleRunner) -> None:
             foo = 4
             [tool.poetry.dev-dependencies]
             """,
-            expected_file_dep=PythonRequirementsFile(
-                {"sources": ["pyproject.toml"]},
+            expected_file_dep=PythonRequirementsFileTarget(
+                {"source": "pyproject.toml"},
                 address=Address("", target_name="pyproject.toml"),
             ),
             expected_targets=[],
@@ -587,8 +587,8 @@ def test_no_tool_poetry(rule_runner: RuleRunner) -> None:
             """
             foo = 4
             """,
-            expected_file_dep=PythonRequirementsFile(
-                {"sources": ["pyproject.toml"]},
+            expected_file_dep=PythonRequirementsFileTarget(
+                {"source": "pyproject.toml"},
                 address=Address("", target_name="pyproject.toml"),
             ),
             expected_targets=[],

src/python/pants/backend/python/macros/python_requirements_caof.py

@@ -70,7 +70,7 @@ def __call__(
         req_file_tgt = self._parse_context.create_object(
             "_python_requirements_file",
             name=source.replace(os.path.sep, "_"),
-            sources=[source],
+            source=source,
         )
         requirements_dep = f":{req_file_tgt.name}"
 

src/python/pants/backend/python/macros/python_requirements_caof_test.py

@@ -8,7 +8,7 @@
 
 from pants.backend.python.macros.python_requirements_caof import PythonRequirementsCAOF
 from pants.backend.python.pip_requirement import PipRequirement
-from pants.backend.python.target_types import PythonRequirementsFile, PythonRequirementTarget
+from pants.backend.python.target_types import PythonRequirementsFileTarget, PythonRequirementTarget
 from pants.engine.addresses import Address
 from pants.engine.internals.scheduler import ExecutionError
 from pants.engine.target import AllTargets
@@ -18,7 +18,7 @@
 @pytest.fixture
 def rule_runner() -> RuleRunner:
     return RuleRunner(
-        target_types=[PythonRequirementTarget, PythonRequirementsFile],
+        target_types=[PythonRequirementTarget, PythonRequirementsFileTarget],
         context_aware_object_factories={"python_requirements": PythonRequirementsCAOF},
     )
 
@@ -28,7 +28,7 @@ def assert_python_requirements(
     build_file_entry: str,
     requirements_txt: str,
     *,
-    expected_file_dep: PythonRequirementsFile,
+    expected_file_dep: PythonRequirementsFileTarget,
     expected_targets: Iterable[PythonRequirementTarget],
     requirements_txt_relpath: str = "requirements.txt",
 ) -> None:
@@ -68,8 +68,8 @@ def test_requirements_txt(rule_runner: RuleRunner) -> None:
             pip@ git+https://github.com/pypa/pip.git
             """
         ),
-        expected_file_dep=PythonRequirementsFile(
-            {"sources": ["requirements.txt"]},
+        expected_file_dep=PythonRequirementsFileTarget(
+            {"source": "requirements.txt"},
             Address("", target_name="requirements.txt"),
         ),
         expected_targets=[
@@ -132,8 +132,8 @@ def test_multiple_versions(rule_runner: RuleRunner) -> None:
             repletewateringcan>=7
             """
         ),
-        expected_file_dep=PythonRequirementsFile(
-            {"sources": ["requirements.txt"]},
+        expected_file_dep=PythonRequirementsFileTarget(
+            {"source": "requirements.txt"},
             Address("", target_name="requirements.txt"),
         ),
         expected_targets=[
@@ -167,7 +167,9 @@ def test_multiple_versions(rule_runner: RuleRunner) -> None:
 
 def test_invalid_req(rule_runner: RuleRunner) -> None:
     """Test that we give a nice error message."""
-    fake_file_tgt = PythonRequirementsFile({"sources": ["doesnt matter"]}, Address("doesnt_matter"))
+    fake_file_tgt = PythonRequirementsFileTarget(
+        {"source": "doesnt matter"}, Address("doesnt_matter")
+    )
     with pytest.raises(ExecutionError) as exc:
         assert_python_requirements(
             rule_runner,
@@ -198,8 +200,8 @@ def test_source_override(rule_runner: RuleRunner) -> None:
         "python_requirements(source='subdir/requirements.txt')",
         "ansicolors>=1.18.0",
         requirements_txt_relpath="subdir/requirements.txt",
-        expected_file_dep=PythonRequirementsFile(
-            {"sources": ["subdir/requirements.txt"]},
+        expected_file_dep=PythonRequirementsFileTarget(
+            {"source": "subdir/requirements.txt"},
             Address("", target_name="subdir_requirements.txt"),
         ),
         expected_targets=[

src/python/pants/backend/python/register.py

@@ -28,7 +28,7 @@
     PexBinariesGeneratorTarget,
     PexBinary,
     PythonDistribution,
-    PythonRequirementsFile,
+    PythonRequirementsFileTarget,
     PythonRequirementTarget,
     PythonSourcesGeneratorTarget,
     PythonSourceTarget,
@@ -91,7 +91,7 @@ def target_types():
         PexBinary,
         PexBinariesGeneratorTarget,
         PythonDistribution,
-        PythonRequirementsFile,
+        PythonRequirementsFileTarget,
         PythonRequirementTarget,
         PythonSourcesGeneratorTarget,
         PythonSourceTarget,

src/python/pants/backend/python/target_types.py

@@ -1073,15 +1073,19 @@ def parse_requirements_file(content: str, *, rel_path: str) -> Iterator[PipRequi
             )
 
 
-class PythonRequirementsFileSourcesField(MultipleSourcesField):
-    required = True
+class PythonRequirementsFileSourcesField(SingleSourceField):
     uses_source_roots = False
 
 
-class PythonRequirementsFile(Target):
+# This allows us to work around https://github.com/pantsbuild/pants/issues/13118. Because a
+# generated target does not depend on its target generator, `--changed-since --changed-dependees`
+# would not mark the generated targets as changing when the `requirements.txt` changes, even though
+# it may be impacted. Fixing that will be A Thing and requires design work, so instead we can
+# depend on this private target type that owns `requirements.txt` to get `--changed-since` working.
+class PythonRequirementsFileTarget(Target):
     alias = "_python_requirements_file"
     core_fields = (*COMMON_TARGET_FIELDS, PythonRequirementsFileSourcesField)
-    help = "A private helper target type for requirements.txt files."
+    help = "A private helper target type used by `python_requirement` target generators."
 
 
 # -----------------------------------------------------------------------------------------------