Make scala_xxx rules declare that they provide JavaInfo (bazel-contrib#1643)

* make scala_xxx declare that they provide JavaInfo
- Made scala_xxx rules declare they provide JavaInfo by setting the provides attribute.
- This allows aspects to visit them when the aspect uses required_providers.
- This matches functionality of java_xxx rules

* lint fix

Author: crt-31

scala/private/rules/scala_binary.bzl

@@ -92,6 +92,7 @@ def make_scala_binary(*extras):
         ],
         cfg = scala_version_transition,
         incompatible_use_toolchain_transition = True,
+        provides = [JavaInfo],
         implementation = _scala_binary_impl,
     )
 

scala/private/rules/scala_junit_test.bzl

@@ -145,6 +145,7 @@ def make_scala_junit_test(*extras):
         ],
         cfg = scala_version_transition,
         incompatible_use_toolchain_transition = True,
+        provides = [JavaInfo],
         implementation = _scala_junit_test_impl,
     )
 

scala/private/rules/scala_library.bzl

@@ -108,6 +108,7 @@ def make_scala_library(*extras):
         ],
         cfg = scala_version_transition,
         incompatible_use_toolchain_transition = True,
+        provides = [JavaInfo],
         implementation = _scala_library_impl,
     )
 
@@ -209,6 +210,7 @@ def make_scala_library_for_plugin_bootstrapping(*extras):
         ],
         cfg = scala_version_transition,
         incompatible_use_toolchain_transition = True,
+        provides = [JavaInfo],
         implementation = _scala_library_for_plugin_bootstrapping_impl,
     )
 
@@ -284,6 +286,7 @@ def make_scala_macro_library(*extras):
         ],
         cfg = scala_version_transition,
         incompatible_use_toolchain_transition = True,
+        provides = [JavaInfo],
         implementation = _scala_macro_library_impl,
     )
 

scala/private/rules/scala_repl.bzl

@@ -87,6 +87,7 @@ def make_scala_repl(*extras):
         ],
         cfg = scala_version_transition,
         incompatible_use_toolchain_transition = True,
+        provides = [JavaInfo],
         implementation = _scala_repl_impl,
     )
 

scala/private/rules/scala_test.bzl

@@ -131,6 +131,7 @@ def make_scala_test(*extras):
         ],
         cfg = scala_version_transition,
         incompatible_use_toolchain_transition = True,
+        provides = [JavaInfo],
         implementation = _scala_test_impl,
     )
 

scala/scala_import.bzl

@@ -150,4 +150,5 @@ scala_import = rule(
         ),
     },
     toolchains = ["@bazel_tools//tools/jdk:toolchain_type"],
+    provides = [JavaInfo],
 )

test/aspect/A.scala

@@ -0,0 +1,7 @@
+package scalarules.test
+
+object A {
+  def main(args: Array[String]) {
+    println("4 8 15 16 23 42")
+  }
+}

test/aspect/B.scala

@@ -0,0 +1,7 @@
+package scalarules.test
+
+object B {
+  def main(args: Array[String]) {
+    println("4 8 15 16 23 42")
+  }
+}

test/aspect/BUILD

@@ -1,11 +1,13 @@
 load(":aspect.bzl", "aspect_testscript")
+load(":javainfo_from_aspect_test.bzl", "javainfo_from_aspect_test")
 load(
     "//scala:scala.bzl",
     "scala_junit_test",
     "scala_library",
     "scala_specs2_junit_test",
     "scala_test",
 )
+load("//scala:scala_import.bzl", "scala_import")
 
 aspect_testscript(
     name = "aspect_testscript",
@@ -39,3 +41,35 @@ scala_specs2_junit_test(
     srcs = ["FakeJunitTest.scala"],
     suffixes = ["Test"],
 )
+
+#####################################
+#use ensure_javainfo_from_aspect_test() to make sure scala_xxx can be visited in an aspect that has required_aspects=[JavaInfo]
+
+scala_import(
+    name = "com_google_guava_guava_21_0",
+    jars = ["@com_google_guava_guava_21_0_with_file//:guava-21.0.jar"],
+)
+
+scala_library(
+    name = "A",
+    srcs = ["A.scala"],
+)
+
+#This library depends on a scala_library and a scala_import
+scala_library(
+    name = "B",
+    deps = [
+        "A",
+        "com_google_guava_guava_21_0",
+    ],
+)
+
+javainfo_from_aspect_test(
+    name = "javainfo_from_aspect_test",
+    expected = [
+        "A",
+        "com_google_guava_guava_21_0",
+    ],
+    target = "B",
+    target_under_test = "B",
+)

test/aspect/javainfo_from_aspect_test.bzl

@@ -0,0 +1,36 @@
+load("@bazel_skylib//lib:unittest.bzl", "analysistest")
+
+_VisitedRulesInfo = provider()
+
+def _aspect_with_javainfo_required_imp(target, ctx):
+    visited = dict([(target.label.name, "")])
+    for dep in ctx.rule.attr.deps:
+        visited.update(dep[_VisitedRulesInfo].visited)
+
+    return [
+        _VisitedRulesInfo(visited = visited),
+    ]
+
+#An aspect that has "required_providers = [JavaInfo]."
+#This is used to test that an aspect that has required_providers can access the JavaInfo provided by the scala_xxx targets
+_aspect_with_javainfo_required = aspect(
+    attr_aspects = ["deps"],
+    required_providers = [JavaInfo],
+    implementation = _aspect_with_javainfo_required_imp,
+)
+
+def _javainfo_from_aspect_test_imp(ctx):
+    testenv = analysistest.begin(ctx)
+
+    for expected in ctx.attr.expected:
+        if (expected not in ctx.attr.target[_VisitedRulesInfo].visited):
+            analysistest.fail(testenv, "Aspect did not visit expected target %s" % ctx.attr.expected)
+    return analysistest.end(testenv)
+
+javainfo_from_aspect_test = analysistest.make(
+    impl = _javainfo_from_aspect_test_imp,
+    attrs = {
+        "target": attr.label(aspects = [_aspect_with_javainfo_required]),
+        "expected": attr.string_list(),  #The targets we expect to be visited by the aspect
+    },
+)