thrift: add scrooge java backend

src/python/pants/backend/codegen/thrift/scrooge/java/BUILD

@@ -0,0 +1,6 @@
+# Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+python_sources()
+
+python_tests(name="tests")

src/python/pants/backend/codegen/thrift/scrooge/java/rules.py

@@ -0,0 +1,72 @@
+# Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+from pants.backend.codegen.thrift.scrooge.java.subsystem import ScroogeJavaSubsystem
+from pants.backend.codegen.thrift.scrooge.rules import (
+    GeneratedScroogeThriftSources,
+    GenerateScroogeThriftSourcesRequest,
+)
+from pants.backend.codegen.thrift.target_types import ThriftDependenciesField, ThriftSourceField
+from pants.backend.java.target_types import JavaSourceField
+from pants.engine.addresses import Addresses, UnparsedAddressInputs
+from pants.engine.fs import AddPrefix, Digest, Snapshot
+from pants.engine.internals.selectors import Get
+from pants.engine.rules import collect_rules, rule
+from pants.engine.target import (
+    GeneratedSources,
+    GenerateSourcesRequest,
+    InjectDependenciesRequest,
+    InjectedDependencies,
+)
+from pants.engine.unions import UnionRule
+from pants.source.source_root import SourceRoot, SourceRootRequest
+from pants.util.logging import LogLevel
+
+
+class GenerateJavaFromThriftRequest(GenerateSourcesRequest):
+    input = ThriftSourceField
+    output = JavaSourceField
+
+
+class InjectScroogeJavaDependencies(InjectDependenciesRequest):
+    inject_for = ThriftDependenciesField
+
+
+@rule(desc="Generate Java from Thrift with Scrooge", level=LogLevel.DEBUG)
+async def generate_java_from_thrift_with_scrooge(
+    request: GenerateJavaFromThriftRequest,
+) -> GeneratedSources:
+    result = await Get(
+        GeneratedScroogeThriftSources,
+        GenerateScroogeThriftSourcesRequest(
+            thrift_source_field=request.protocol_target[ThriftSourceField],
+            lang_id="java",
+            lang_name="Java",
+        ),
+    )
+
+    source_root = await Get(
+        SourceRoot, SourceRootRequest, SourceRootRequest.for_target(request.protocol_target)
+    )
+
+    source_root_restored = (
+        await Get(Snapshot, AddPrefix(result.snapshot.digest, source_root.path))
+        if source_root.path != "."
+        else await Get(Snapshot, Digest, result.snapshot.digest)
+    )
+    return GeneratedSources(source_root_restored)
+
+
+@rule
+async def inject_scrooge_java_dependencies(
+    _: InjectScroogeJavaDependencies, scrooge: ScroogeJavaSubsystem
+) -> InjectedDependencies:
+    addresses = await Get(Addresses, UnparsedAddressInputs, scrooge.runtime_dependencies)
+    return InjectedDependencies(addresses)
+
+
+def rules():
+    return (
+        *collect_rules(),
+        UnionRule(GenerateSourcesRequest, GenerateJavaFromThriftRequest),
+        UnionRule(InjectDependenciesRequest, InjectScroogeJavaDependencies),
+    )

src/python/pants/backend/codegen/thrift/scrooge/java/rules_integration_test.py

@@ -0,0 +1,172 @@
+# Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+from __future__ import annotations
+
+from textwrap import dedent
+
+import pytest
+
+from pants.backend.codegen.thrift.rules import rules as thrift_rules
+from pants.backend.codegen.thrift.scrooge.java.rules import GenerateJavaFromThriftRequest
+from pants.backend.codegen.thrift.scrooge.java.rules import rules as scrooge_java_rules
+from pants.backend.codegen.thrift.scrooge.rules import rules as scrooge_rules
+from pants.backend.codegen.thrift.target_types import (
+    ThriftSourceField,
+    ThriftSourcesGeneratorTarget,
+)
+from pants.backend.scala import target_types
+from pants.backend.scala.compile.scalac import rules as scalac_rules
+from pants.backend.scala.target_types import ScalaSourcesGeneratorTarget, ScalaSourceTarget
+from pants.build_graph.address import Address
+from pants.core.util_rules import config_files, source_files, stripped_source_files
+from pants.core.util_rules.external_tool import rules as external_tool_rules
+from pants.engine.rules import QueryRule
+from pants.engine.target import GeneratedSources, HydratedSources, HydrateSourcesRequest
+from pants.jvm import classpath
+from pants.jvm.jdk_rules import rules as jdk_rules
+from pants.jvm.resolve.coursier_fetch import rules as coursier_fetch_rules
+from pants.jvm.resolve.coursier_setup import rules as coursier_setup_rules
+from pants.jvm.util_rules import rules as util_rules
+from pants.testutil.rule_runner import PYTHON_BOOTSTRAP_ENV, RuleRunner
+
+
+@pytest.fixture
+def rule_runner() -> RuleRunner:
+    rule_runner = RuleRunner(
+        rules=[
+            *thrift_rules(),
+            *scrooge_rules(),
+            *scrooge_java_rules(),
+            *config_files.rules(),
+            *classpath.rules(),
+            *coursier_fetch_rules(),
+            *coursier_setup_rules(),
+            *external_tool_rules(),
+            *source_files.rules(),
+            *scalac_rules(),
+            *util_rules(),
+            *jdk_rules(),
+            *target_types.rules(),
+            *stripped_source_files.rules(),
+            QueryRule(HydratedSources, [HydrateSourcesRequest]),
+            QueryRule(GeneratedSources, [GenerateJavaFromThriftRequest]),
+        ],
+        target_types=[
+            ScalaSourceTarget,
+            ScalaSourcesGeneratorTarget,
+            ThriftSourcesGeneratorTarget,
+        ],
+    )
+    rule_runner.set_options(
+        [],
+        env_inherit=PYTHON_BOOTSTRAP_ENV,
+    )
+    return rule_runner
+
+
+def assert_files_generated(
+    rule_runner: RuleRunner,
+    address: Address,
+    *,
+    expected_files: list[str],
+    source_roots: list[str],
+    extra_args: list[str] | None = None,
+) -> None:
+    args = [f"--source-root-patterns={repr(source_roots)}", *(extra_args or ())]
+    rule_runner.set_options(args, env_inherit={"PATH", "PYENV_ROOT", "HOME"})
+    tgt = rule_runner.get_target(address)
+    thrift_sources = rule_runner.request(
+        HydratedSources, [HydrateSourcesRequest(tgt[ThriftSourceField])]
+    )
+    generated_sources = rule_runner.request(
+        GeneratedSources,
+        [GenerateJavaFromThriftRequest(thrift_sources.snapshot, tgt)],
+    )
+    assert set(generated_sources.snapshot.files) == set(expected_files)
+
+
+def test_generates_java(rule_runner: RuleRunner) -> None:
+    # This tests a few things:
+    #  * We generate the correct file names.
+    #  * Thrift files can import other thrift files, and those can import others
+    #    (transitive dependencies). We'll only generate the requested target, though.
+    #  * We can handle multiple source roots, which need to be preserved in the final output.
+    rule_runner.write_files(
+        {
+            "src/thrift/dir1/f.thrift": dedent(
+                """\
+                namespace java org.pantsbuild.example
+                struct Person {
+                  1: string name
+                  2: i32 id
+                  3: string email
+                }
+                """
+            ),
+            "src/thrift/dir1/f2.thrift": dedent(
+                """\
+                namespace java org.pantsbuild.example
+                include "dir1/f.thrift"
+                struct ManagedPerson {
+                  1: f.Person employee
+                  2: f.Person manager
+                }
+                """
+            ),
+            "src/thrift/dir1/BUILD": "thrift_sources()",
+            "src/thrift/dir2/g.thrift": dedent(
+                """\
+                namespace java org.pantsbuild.example
+                include "dir1/f2.thrift"
+                struct ManagedPersonWrapper {
+                  1: f2.ManagedPerson managed_person
+                }
+                """
+            ),
+            "src/thrift/dir2/BUILD": "thrift_sources(dependencies=['src/thrift/dir1'])",
+            # Test another source root.
+            "tests/thrift/test_thrifts/f.thrift": dedent(
+                """\
+                namespace java org.pantsbuild.example
+                include "dir2/g.thrift"
+                struct Executive {
+                  1: g.ManagedPersonWrapper managed_person_wrapper
+                }
+                """
+            ),
+            "tests/thrift/test_thrifts/BUILD": "thrift_sources(dependencies=['src/thrift/dir2'])",
+        }
+    )
+
+    def assert_gen(addr: Address, expected: list[str]) -> None:
+        assert_files_generated(
+            rule_runner,
+            addr,
+            source_roots=["src/python", "/src/thrift", "/tests/thrift"],
+            expected_files=expected,
+        )
+
+    assert_gen(
+        Address("src/thrift/dir1", relative_file_path="f.thrift"),
+        [
+            "src/thrift/org/pantsbuild/example/Person.java",
+        ],
+    )
+    assert_gen(
+        Address("src/thrift/dir1", relative_file_path="f2.thrift"),
+        [
+            "src/thrift/org/pantsbuild/example/ManagedPerson.java",
+        ],
+    )
+    assert_gen(
+        Address("src/thrift/dir2", relative_file_path="g.thrift"),
+        [
+            "src/thrift/org/pantsbuild/example/ManagedPersonWrapper.java",
+        ],
+    )
+    assert_gen(
+        Address("tests/thrift/test_thrifts", relative_file_path="f.thrift"),
+        [
+            "tests/thrift/org/pantsbuild/example/Executive.java",
+        ],
+    )

src/python/pants/backend/codegen/thrift/scrooge/java/subsystem.py

@@ -0,0 +1,33 @@
+# Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+from __future__ import annotations
+
+from pants.engine.addresses import UnparsedAddressInputs
+from pants.option.custom_types import target_option
+from pants.option.subsystem import Subsystem
+
+
+class ScroogeJavaSubsystem(Subsystem):
+    options_scope = "scrooge-java"
+    help = "Java-specific options for the Scrooge Thrift IDL compiler (https://twitter.github.io/scrooge/)."
+
+    @classmethod
+    def register_options(cls, register):
+        super().register_options(register)
+        register(
+            "--runtime-dependencies",
+            type=list,
+            member_type=target_option,
+            help=(
+                "A list of addresses to `jvm_artifact` targets for the runtime "
+                "dependencies needed for generated Java code to work. For example, "
+                "`['3rdparty/jvm:libthrift']`. These dependencies will "
+                "be automatically added to every `thrift_source` target. At the very least, "
+                "this option must be set to a `jvm_artifact` for the "
+                "`org.apache.thrift:libthrift` runtime library."
+            ),
+        )
+
+    @property
+    def runtime_dependencies(self) -> UnparsedAddressInputs:
+        return UnparsedAddressInputs(self.options.runtime_dependencies, owning_address=None)

src/python/pants/backend/codegen/thrift/scrooge/scala/rules_integration_test.py

@@ -96,7 +96,7 @@ def test_generates_python(rule_runner: RuleRunner) -> None:
         {
             "src/thrift/dir1/f.thrift": dedent(
                 """\
-                namespace py dir1
+                #@namespace scala org.pantsbuild.example
                 struct Person {
                   1: string name
                   2: i32 id
@@ -106,7 +106,7 @@ def test_generates_python(rule_runner: RuleRunner) -> None:
             ),
             "src/thrift/dir1/f2.thrift": dedent(
                 """\
-                namespace py dir1
+                #@namespace scala org.pantsbuild.example
                 include "dir1/f.thrift"
                 struct ManagedPerson {
                   1: f.Person employee
@@ -117,6 +117,7 @@ def test_generates_python(rule_runner: RuleRunner) -> None:
             "src/thrift/dir1/BUILD": "thrift_sources()",
             "src/thrift/dir2/g.thrift": dedent(
                 """\
+                #@namespace scala org.pantsbuild.example
                 include "dir1/f2.thrift"
                 struct ManagedPersonWrapper {
                   1: f2.ManagedPerson managed_person
@@ -127,6 +128,7 @@ def test_generates_python(rule_runner: RuleRunner) -> None:
             # Test another source root.
             "tests/thrift/test_thrifts/f.thrift": dedent(
                 """\
+                #@namespace scala org.pantsbuild.example
                 include "dir2/g.thrift"
                 struct Executive {
                   1: g.ManagedPersonWrapper managed_person_wrapper
@@ -145,30 +147,27 @@ def assert_gen(addr: Address, expected: list[str]) -> None:
             expected_files=expected,
         )
 
-    # TODO: Why is generated path `src/thrift/thrift`?
     assert_gen(
         Address("src/thrift/dir1", relative_file_path="f.thrift"),
         [
-            "src/thrift/thrift/Person.scala",
+            "src/thrift/org/pantsbuild/example/Person.scala",
         ],
     )
     assert_gen(
         Address("src/thrift/dir1", relative_file_path="f2.thrift"),
         [
-            "src/thrift/thrift/ManagedPerson.scala",
+            "src/thrift/org/pantsbuild/example/ManagedPerson.scala",
         ],
     )
-    # TODO: Fix package namespacing?
     assert_gen(
         Address("src/thrift/dir2", relative_file_path="g.thrift"),
         [
-            "src/thrift/thrift/ManagedPersonWrapper.scala",
+            "src/thrift/org/pantsbuild/example/ManagedPersonWrapper.scala",
         ],
     )
-    # TODO: Fix namespacing.
     assert_gen(
         Address("tests/thrift/test_thrifts", relative_file_path="f.thrift"),
         [
-            "tests/thrift/thrift/Executive.scala",
+            "tests/thrift/org/pantsbuild/example/Executive.scala",
         ],
     )

src/python/pants/backend/experimental/codegen/thrift/scrooge/java/BUILD

@@ -0,0 +1,4 @@
+# Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+python_sources()