infer go_external_module targets

[ci skip-rust]

[ci skip-build-wheels]

src/python/pants/backend/go/tailor.py

@@ -1,9 +1,12 @@
 # Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
+import itertools
 import os
 from dataclasses import dataclass
 
-from pants.backend.go.target_types import GoModule, GoPackage
+from pants.backend.go.module import ResolvedGoModule, ResolveGoModuleRequest
+from pants.backend.go.target_types import GoExternalModule, GoModule, GoModuleSources, GoPackage
+from pants.base.specs import AddressSpecs, MaybeEmptyDescendantAddresses, MaybeEmptySiblingAddresses
 from pants.core.goals.tailor import (
     AllOwnedSources,
     PutativeTarget,
@@ -14,6 +17,7 @@
 from pants.engine.fs import PathGlobs, Paths
 from pants.engine.internals.selectors import Get
 from pants.engine.rules import collect_rules, rule
+from pants.engine.target import UnexpandedTargets
 from pants.engine.unions import UnionRule
 from pants.util.logging import LogLevel
 
@@ -70,9 +74,71 @@ async def find_putative_go_module_targets(
     return PutativeTargets(putative_targets)
 
 
+def compute_go_external_module_target_name(name: str, version: str) -> str:
+    return f"{name.replace('/', '_')}_{version}"
+
+
+@dataclass(frozen=True)
+class PutativeGoExternalModuleTargetsRequest(PutativeTargetsRequest):
+    pass
+
+
+@rule(level=LogLevel.DEBUG, desc="Determine candidate Go `go_external_module` targets to create")
+async def find_putative_go_external_module_targets(
+    request: PutativeGoExternalModuleTargetsRequest, _all_owned_sources: AllOwnedSources
+) -> PutativeTargets:
+    # Unlike ordinary tailor invocations, this rule looks at existing `go_module` targets and not at actual
+    # source files because it infers `go_external_module` targets based on go.mod contents. (This may require
+    # invoking `tailor` first to create `go_module` targets and then again to create `go_external_module`
+    # targets.)
+
+    addresses = itertools.chain.from_iterable(
+        [
+            [MaybeEmptySiblingAddresses(search_path), MaybeEmptyDescendantAddresses(search_path)]
+            for search_path in request.search_paths.dirs
+        ]
+    )
+    candidate_targets = await Get(UnexpandedTargets, AddressSpecs(addresses))
+    go_module_targets = [
+        tgt
+        for tgt in candidate_targets
+        if tgt.has_field(GoModuleSources) and not tgt.address.is_file_target
+    ]
+
+    putative_targets = []
+
+    for go_module_target in go_module_targets:
+        resolved_go_module = await Get(
+            ResolvedGoModule, ResolveGoModuleRequest(go_module_target.address)
+        )
+        for module_descriptor in resolved_go_module.modules:
+            putative_targets.append(
+                PutativeTarget.for_target_type(
+                    GoExternalModule,
+                    go_module_target.address.spec_path,
+                    compute_go_external_module_target_name(
+                        module_descriptor.module_path, module_descriptor.module_version
+                    ),
+                    [],
+                    kwargs={
+                        "path": module_descriptor.module_path,
+                        "version": module_descriptor.module_version,
+                        "import_path": module_descriptor.import_path,
+                    },
+                    build_file_name="BUILD.godeps",
+                    comments=(
+                        "Auto-generated by `./pants tailor`. Re-run `./pants tailor` if go.mod changes.",
+                    ),
+                )
+            )
+
+    return PutativeTargets(putative_targets)
+
+
 def rules():
     return [
         *collect_rules(),
         UnionRule(PutativeTargetsRequest, PutativeGoPackageTargetsRequest),
         UnionRule(PutativeTargetsRequest, PutativeGoModuleTargetsRequest),
+        UnionRule(PutativeTargetsRequest, PutativeGoExternalModuleTargetsRequest),
     ]

src/python/pants/backend/go/tailor_test.py

@@ -1,33 +1,61 @@
 # Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
-from pants.backend.go.tailor import PutativeGoModuleTargetsRequest, PutativeGoPackageTargetsRequest
+import textwrap
+
+import pytest
+
+from pants.backend.go import module, target_type_rules
+from pants.backend.go.module import ResolvedGoModule, ResolveGoModuleRequest
+from pants.backend.go.tailor import (
+    PutativeGoExternalModuleTargetsRequest,
+    PutativeGoModuleTargetsRequest,
+    PutativeGoPackageTargetsRequest,
+)
 from pants.backend.go.tailor import rules as go_tailor_rules
-from pants.backend.go.target_types import GoModule, GoPackage
+from pants.backend.go.target_types import GoExternalModule, GoModule, GoPackage
 from pants.core.goals.tailor import (
     AllOwnedSources,
     PutativeTarget,
     PutativeTargets,
     PutativeTargetsSearchPaths,
 )
 from pants.core.goals.tailor import rules as core_tailor_rules
+from pants.core.util_rules import external_tool, source_files
+from pants.engine.addresses import Addresses
 from pants.engine.rules import QueryRule
+from pants.engine.target import DependenciesRequest, UnexpandedTargets
 from pants.testutil.rule_runner import RuleRunner
 
 
-def test_find_putative_go_package_targets() -> None:
+@pytest.fixture
+def rule_runner() -> RuleRunner:
     rule_runner = RuleRunner(
         rules=[
             *core_tailor_rules(),
             *go_tailor_rules(),
+            *external_tool.rules(),
+            *source_files.rules(),
+            *module.rules(),
+            *target_type_rules.rules(),
             QueryRule(PutativeTargets, [PutativeGoPackageTargetsRequest, AllOwnedSources]),
+            QueryRule(PutativeTargets, [PutativeGoModuleTargetsRequest, AllOwnedSources]),
+            QueryRule(PutativeTargets, [PutativeGoExternalModuleTargetsRequest, AllOwnedSources]),
             QueryRule(AllOwnedSources, ()),
+            QueryRule(Addresses, (DependenciesRequest,)),
+            QueryRule(UnexpandedTargets, (Addresses,)),
+            QueryRule(ResolvedGoModule, [ResolveGoModuleRequest]),
         ],
         target_types=[
             GoPackage,
+            GoModule,
+            GoExternalModule,
         ],
     )
     rule_runner.set_options(["--backend-packages=pants.backend.experimental.go"])
+    return rule_runner
+
 
+def test_find_putative_go_package_targets(rule_runner: RuleRunner) -> None:
     rule_runner.write_files(
         {
             "src/go/owned/BUILD": "go_package()\n",
@@ -60,20 +88,7 @@ def test_find_putative_go_package_targets() -> None:
     )
 
 
-def test_find_putative_go_module_targets() -> None:
-    rule_runner = RuleRunner(
-        rules=[
-            *core_tailor_rules(),
-            *go_tailor_rules(),
-            QueryRule(PutativeTargets, [PutativeGoModuleTargetsRequest, AllOwnedSources]),
-            QueryRule(AllOwnedSources, ()),
-        ],
-        target_types=[
-            GoModule,
-        ],
-    )
-    rule_runner.set_options(["--backend-packages=pants.backend.experimental.go"])
-
+def test_find_putative_go_module_targets(rule_runner: RuleRunner) -> None:
     rule_runner.write_files(
         {
             "src/go/owned/BUILD": "go_module()\n",
@@ -104,3 +119,50 @@ def test_find_putative_go_module_targets() -> None:
             ),
         ]
     )
+
+
+def test_find_putative_go_external_module_targets(rule_runner: RuleRunner) -> None:
+    rule_runner.write_files(
+        {
+            "src/go/BUILD": "go_module()\n",
+            "src/go/go.mod": textwrap.dedent(
+                """\
+            module example.com/src/go
+            go 1.16
+            require (
+                github.com/google/uuid v1.2.0
+            )
+            """
+            ),
+        }
+    )
+    putative_targets = rule_runner.request(
+        PutativeTargets,
+        [
+            PutativeGoExternalModuleTargetsRequest(PutativeTargetsSearchPaths(("src/",))),
+            AllOwnedSources(
+                [
+                    "src/go/go.mod",
+                ]
+            ),
+        ],
+    )
+    assert putative_targets == PutativeTargets(
+        [
+            PutativeTarget.for_target_type(
+                GoExternalModule,
+                "src/go",
+                "github.com_google_uuid_v1.2.0",
+                [],
+                kwargs={
+                    "path": "github.com/google/uuid",
+                    "version": "v1.2.0",
+                    "import_path": "github.com/google/uuid",
+                },
+                build_file_name="BUILD.godeps",
+                comments=(
+                    "Auto-generated by `./pants tailor`. Re-run `./pants tailor` if go.mod changes.",
+                ),
+            ),
+        ]
+    )