Add JSX support built on the JS backend

.gitignore

@@ -68,3 +68,4 @@ GTAGS
 /.venv
 .tool-versions
 TAGS
+node_modules

docs/notes/2.23.x.md

@@ -170,6 +170,9 @@ Pants now applies dependency inference according to the most permissive "bundler
 [jsconfig.json](https://code.visualstudio.com/docs/languages/jsconfig), when a jsconfig.json is
 part of your javascript workspace.
 
+Pants now ships with experimental JSX support, including Prettier formatting and JS testing as part of the
+JS backend.
+
 #### Shell
 
 The `tailor` goal now has independent options for tailoring `shell_sources` and `shunit2_tests` targets. The option was split from `tailor` into [`tailor_sources`](https://www.pantsbuild.org/2.23/reference/subsystems/shell-setup#tailor_sources) and [`tailor_shunit2_tests`](https://www.pantsbuild.org/2.23/reference/subsystems/shell-setup#tailor_shunit2_tests).

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

@@ -16,6 +16,13 @@
     JSTestsGeneratorTarget,
     JSTestTarget,
 )
+from pants.backend.jsx.goals import tailor as jsx_tailor
+from pants.backend.jsx.target_types import (
+    JSXSourcesGeneratorTarget,
+    JSXSourceTarget,
+    JSXTestsGeneratorTarget,
+    JSXTestTarget,
+)
 from pants.build_graph.build_file_aliases import BuildFileAliases
 from pants.engine.rules import Rule
 from pants.engine.target import Target
@@ -31,6 +38,7 @@ def rules() -> Iterable[Rule | UnionRule]:
         *run_rules(),
         *test.rules(),
         *export.rules(),
+        *jsx_tailor.rules(),
     )
 
 
@@ -40,6 +48,10 @@ def target_types() -> Iterable[type[Target]]:
         JSSourcesGeneratorTarget,
         JSTestTarget,
         JSTestsGeneratorTarget,
+        JSXSourceTarget,
+        JSXSourcesGeneratorTarget,
+        JSXTestTarget,
+        JSXTestsGeneratorTarget,
         *package_json.target_types(),
     )
 

src/python/pants/backend/javascript/dependency_inference/rules.py

@@ -25,9 +25,10 @@
 from pants.backend.javascript.subsystems.nodejs_infer import NodeJSInfer
 from pants.backend.javascript.target_types import (
     JS_FILE_EXTENSIONS,
-    JSDependenciesField,
-    JSSourceField,
+    JSRuntimeDependenciesField,
+    JSRuntimeSourceField,
 )
+from pants.backend.jsx.target_types import JSX_FILE_EXTENSIONS
 from pants.backend.typescript import tsconfig
 from pants.backend.typescript.tsconfig import ParentTSConfigRequest, TSConfig, find_parent_ts_config
 from pants.build_graph.address import Address
@@ -74,10 +75,10 @@ class InferNodePackageDependenciesRequest(InferDependenciesRequest):
 
 @dataclass(frozen=True)
 class JSSourceInferenceFieldSet(FieldSet):
-    required_fields = (JSSourceField, JSDependenciesField)
+    required_fields = (JSRuntimeSourceField, JSRuntimeDependenciesField)
 
-    source: JSSourceField
-    dependencies: JSDependenciesField
+    source: JSRuntimeSourceField
+    dependencies: JSRuntimeDependenciesField
 
 
 class InferJSDependenciesRequest(InferDependenciesRequest):
@@ -96,7 +97,9 @@ async def infer_node_package_dependencies(
     )
     candidate_js_files = await Get(Owners, OwnersRequest(tuple(entry_points.globs_from_root())))
     js_targets = await Get(Targets, Addresses(candidate_js_files))
-    return InferredDependencies(tgt.address for tgt in js_targets if tgt.has_field(JSSourceField))
+    return InferredDependencies(
+        tgt.address for tgt in js_targets if tgt.has_field(JSRuntimeSourceField)
+    )
 
 
 class NodePackageCandidateMap(FrozenDict[str, Address]):
@@ -155,7 +158,8 @@ async def _prepare_inference_metadata(address: Address, file_path: str) -> Infer
 
 
 def _add_extensions(file_imports: frozenset[str]) -> PathGlobs:
-    extensions = JS_FILE_EXTENSIONS + tuple(f"/index{ext}" for ext in JS_FILE_EXTENSIONS)
+    file_extensions = (*JS_FILE_EXTENSIONS, *JSX_FILE_EXTENSIONS)
+    extensions = file_extensions + tuple(f"/index{ext}" for ext in file_extensions)
     return PathGlobs(
         string
         for file_import in file_imports
@@ -227,12 +231,12 @@ async def infer_js_source_dependencies(
     request: InferJSDependenciesRequest,
     nodejs_infer: NodeJSInfer,
 ) -> InferredDependencies:
-    source: JSSourceField = request.field_set.source
+    source: JSRuntimeSourceField = request.field_set.source
     if not nodejs_infer.imports:
         return InferredDependencies(())
 
     sources = await Get(
-        HydratedSources, HydrateSourcesRequest(source, for_sources_types=[JSSourceField])
+        HydratedSources, HydrateSourcesRequest(source, for_sources_types=[JSRuntimeSourceField])
     )
     metadata = await _prepare_inference_metadata(request.field_set.address, source.file_path)
 

src/python/pants/backend/javascript/goals/test.py

@@ -22,13 +22,7 @@
     OwningNodePackageRequest,
 )
 from pants.backend.javascript.subsystems.nodejstest import NodeJSTest
-from pants.backend.javascript.target_types import (
-    JSSourceField,
-    JSTestBatchCompatibilityTagField,
-    JSTestExtraEnvVarsField,
-    JSTestSourceField,
-    JSTestTimeoutField,
-)
+from pants.backend.javascript.target_types import JSRuntimeSourceField, JSTestRuntimeSourceField
 from pants.base.glob_match_error_behavior import GlobMatchErrorBehavior
 from pants.build_graph.address import Address
 from pants.core.goals.test import (
@@ -37,10 +31,13 @@
     CoverageReports,
     FilesystemCoverageReport,
     TestExtraEnv,
+    TestExtraEnvVarsField,
     TestFieldSet,
     TestRequest,
     TestResult,
+    TestsBatchCompatibilityTagField,
     TestSubsystem,
+    TestTimeoutField,
 )
 from pants.core.target_types import AssetSourceField
 from pants.core.util_rules import source_files
@@ -88,13 +85,13 @@ class JSCoverageDataCollection(CoverageDataCollection[JSCoverageData]):
 
 @dataclass(frozen=True)
 class JSTestFieldSet(TestFieldSet):
-    required_fields = (JSTestSourceField,)
+    required_fields = (JSTestRuntimeSourceField,)
 
-    batch_compatibility_tag: JSTestBatchCompatibilityTagField
-    source: JSTestSourceField
+    batch_compatibility_tag: TestsBatchCompatibilityTagField
+    source: JSTestRuntimeSourceField
     dependencies: Dependencies
-    timeout: JSTestTimeoutField
-    extra_env_vars: JSTestExtraEnvVarsField
+    timeout: TestTimeoutField
+    extra_env_vars: TestExtraEnvVarsField
 
 
 class JSTestRequest(TestRequest):
@@ -174,7 +171,7 @@ async def run_javascript_tests(
         SourceFilesRequest(
             (tgt.get(SourcesField) for tgt in transitive_tgts.closure),
             enable_codegen=True,
-            for_sources_types=[JSSourceField, AssetSourceField],
+            for_sources_types=[JSRuntimeSourceField, AssetSourceField],
         ),
     )
     merged_digest = await Get(Digest, MergeDigests([sources.snapshot.digest, installation.digest]))

src/python/pants/backend/javascript/install_node_package.py

@@ -20,7 +20,7 @@
 )
 from pants.backend.javascript.package_manager import PackageManager
 from pants.backend.javascript.subsystems import nodejs
-from pants.backend.javascript.target_types import JSSourceField
+from pants.backend.javascript.target_types import JSRuntimeSourceField
 from pants.build_graph.address import Address
 from pants.core.target_types import FileSourceField, ResourceSourceField
 from pants.core.util_rules.source_files import SourceFiles, SourceFilesRequest
@@ -71,7 +71,7 @@ async def _get_relevant_source_files(
         SourceFilesRequest(
             sources,
             for_sources_types=(PackageJsonSourceField, FileSourceField)
-            + ((ResourceSourceField, JSSourceField) if with_js else ()),
+            + ((ResourceSourceField, JSRuntimeSourceField) if with_js else ()),
             enable_codegen=True,
         ),
     )

src/python/pants/backend/javascript/lint/prettier/rules.py

@@ -11,7 +11,7 @@
 from pants.backend.javascript.lint.prettier.subsystem import Prettier
 from pants.backend.javascript.subsystems import nodejs_tool
 from pants.backend.javascript.subsystems.nodejs_tool import NodeJSToolRequest
-from pants.backend.javascript.target_types import JSSourceField
+from pants.backend.javascript.target_types import JSRuntimeSourceField
 from pants.core.goals.fmt import FmtResult, FmtTargetsRequest
 from pants.core.util_rules.config_files import ConfigFiles, ConfigFilesRequest
 from pants.core.util_rules.partitions import PartitionerType
@@ -28,9 +28,9 @@
 
 @dataclass(frozen=True)
 class PrettierFmtFieldSet(FieldSet):
-    required_fields = (JSSourceField,)
+    required_fields = (JSRuntimeSourceField,)
 
-    sources: JSSourceField
+    sources: JSRuntimeSourceField
 
 
 class PrettierFmtRequest(FmtTargetsRequest):

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

@@ -25,11 +25,23 @@
 JS_TEST_FILE_EXTENSIONS = tuple(f"*.test{ext}" for ext in JS_FILE_EXTENSIONS)
 
 
-class JSDependenciesField(Dependencies):
+class JSRuntimeDependenciesField(Dependencies):
+    """Dependencies of a target that is javascript at runtime."""
+
+
+class JSDependenciesField(JSRuntimeDependenciesField):
     pass
 
 
-class JSSourceField(SingleSourceField):
+class JSRuntimeSourceField(SingleSourceField):
+    """A source that is javascript at runtime."""
+
+
+class JSTestRuntimeSourceField(SingleSourceField):
+    """A source that is runnable by javascript test-runners at runtime."""
+
+
+class JSSourceField(JSRuntimeSourceField):
     expected_file_extensions = JS_FILE_EXTENSIONS
 
 
@@ -86,7 +98,7 @@ class JSTestDependenciesField(JSDependenciesField):
     pass
 
 
-class JSTestSourceField(JSSourceField):
+class JSTestSourceField(JSSourceField, JSTestRuntimeSourceField):
     expected_file_extensions = JS_FILE_EXTENSIONS
 
 

src/python/pants/backend/jsx/BUILD

@@ -0,0 +1,11 @@
+# Copyright 2024 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+# NOTE: Sources restricted from the default for python_sources due to conflict with
+#   - //:all-__init__.py-files
+#   - //src/python/pants/backend/jsx/__init__.py:../../../../../all-__init__.py-files
+python_sources(
+    sources=[
+        "target_types.py",
+    ],
+)

src/python/pants/backend/jsx/goals/BUILD

@@ -0,0 +1,6 @@
+# Copyright 2024 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/jsx/goals/tailor.py

@@ -0,0 +1,62 @@
+# Copyright 2024 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+from __future__ import annotations
+
+import dataclasses
+from dataclasses import dataclass
+from typing import Iterable
+
+from pants.backend.jsx.target_types import (
+    JSX_FILE_EXTENSIONS,
+    JSXSourcesGeneratorTarget,
+    JSXTestsGeneratorSourcesField,
+    JSXTestsGeneratorTarget,
+)
+from pants.core.goals.tailor import (
+    AllOwnedSources,
+    PutativeTarget,
+    PutativeTargets,
+    PutativeTargetsRequest,
+)
+from pants.core.util_rules.ownership import get_unowned_files_for_globs
+from pants.core.util_rules.source_files import classify_files_for_sources_and_tests
+from pants.engine.rules import Rule, collect_rules, rule
+from pants.engine.unions import UnionRule
+from pants.util.dirutil import group_by_dir
+from pants.util.logging import LogLevel
+
+
+@dataclass(frozen=True)
+class PutativeJSXTargetsRequest(PutativeTargetsRequest):
+    pass
+
+
+@rule(level=LogLevel.DEBUG, desc="Determine candidate JSX targets to create")
+async def find_putative_jsx_targets(
+    req: PutativeJSXTargetsRequest, all_owned_sources: AllOwnedSources
+) -> PutativeTargets:
+    unowned_jsx_files = await get_unowned_files_for_globs(
+        req, all_owned_sources, (f"*{ext}" for ext in JSX_FILE_EXTENSIONS)
+    )
+    classified_unowned_js_files = classify_files_for_sources_and_tests(
+        paths=unowned_jsx_files,
+        test_file_glob=JSXTestsGeneratorSourcesField.default,
+        sources_generator=JSXSourcesGeneratorTarget,
+        tests_generator=JSXTestsGeneratorTarget,
+    )
+
+    return PutativeTargets(
+        PutativeTarget.for_target_type(
+            tgt_type, path=dirname, name=name, triggering_sources=sorted(filenames)
+        )
+        for tgt_type, paths, name in (dataclasses.astuple(f) for f in classified_unowned_js_files)
+        for dirname, filenames in group_by_dir(paths).items()
+    )
+
+
+def rules() -> Iterable[Rule | UnionRule]:
+    return (
+        *collect_rules(),
+        UnionRule(PutativeTargetsRequest, PutativeJSXTargetsRequest),
+    )