[internal] java: add debug goal to dump first-party dep map (pantsbui…

…ld#13314)

Add `java-dump-first-party-dep-map` goal to dump the `FirstPartyJavaPackageMapping` type used in dependency inference mapping for Java.

This is gated behind the `pants.backend.experimental.java.debug_goals` backend package so ordinary users won't see it.

build-support/bin/generate_docs.py

@@ -199,7 +199,11 @@ def create_parser() -> argparse.ArgumentParser:
 
 
 def run_pants_help_all() -> dict[str, Any]:
-    deactivated_backends = ["internal_plugins.releases", "pants.backend.experimental.java"]
+    deactivated_backends = [
+        "internal_plugins.releases",
+        "pants.backend.experimental.java",
+        "pants.backend.experimental.java.debug_goals",
+    ]
     activated_backends = [
         "pants.backend.codegen.protobuf.python",
         "pants.backend.awslambda.python",

pants.toml

@@ -18,6 +18,7 @@ backend_packages.add = [
   "pants.backend.experimental.docker",
   "pants.backend.experimental.go",
   "pants.backend.experimental.java",
+  "pants.backend.experimental.java.debug_goals",
   "pants.backend.experimental.python",
   "internal_plugins.releases",
 ]

src/python/pants/backend/experimental/java/debug_goals/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()

src/python/pants/backend/experimental/java/debug_goals/register.py

@@ -0,0 +1,7 @@
+# Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+from pants.backend.java.goals import debug_goals
+
+
+def rules():
+    return [*debug_goals.rules()]

src/python/pants/backend/java/goals/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()

src/python/pants/backend/java/goals/debug_goals.py

@@ -0,0 +1,36 @@
+# Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+import json
+
+from pants.backend.experimental.java.register import rules as java_rules
+from pants.backend.java.dependency_inference.package_mapper import FirstPartyJavaPackageMapping
+from pants.engine.console import Console
+from pants.engine.goal import Goal, GoalSubsystem
+from pants.engine.rules import collect_rules, goal_rule
+
+
+class DumpFirstPartyDepMapSubsystem(GoalSubsystem):
+    name = "java-dump-first-party-dep-map"
+    help = "Dump dependency inference data for Java dep inference."
+
+
+class DumpFirstPartyDepMap(Goal):
+    subsystem_cls = DumpFirstPartyDepMapSubsystem
+
+
+@goal_rule
+async def dump_dep_inference_data(
+    console: Console, first_party_dep_map: FirstPartyJavaPackageMapping
+) -> DumpFirstPartyDepMap:
+    console.write_stdout(
+        json.dumps(first_party_dep_map.package_rooted_dependency_map.to_json_dict())
+    )
+    return DumpFirstPartyDepMap(exit_code=0)
+
+
+def rules():
+    return [
+        *collect_rules(),
+        *java_rules(),
+    ]

src/python/pants/init/BUILD

@@ -13,6 +13,7 @@ target(
         "src/python/pants/backend/experimental/docker/lint/hadolint",
         "src/python/pants/backend/experimental/go",
         "src/python/pants/backend/experimental/java",
+        "src/python/pants/backend/experimental/java/debug_goals",
         "src/python/pants/backend/experimental/python",
         "src/python/pants/backend/experimental/terraform",
         "src/python/pants/backend/google_cloud_function/python",