Fix Intellij Bazel Plugin support for scrooge_scala_library rule (#562)

* Thread output jars thru so IntelliJ can pick them up.

* Fix linting errors.

* Add todo to remove scala field/provider

* Do not collect exported jars.

Author: beala-stripe

twitter_scrooge/twitter_scrooge.bzl

@@ -218,15 +218,13 @@ def _compile_scala(ctx, label, output, scrooge_jar, deps_java_info,
       scalac_jvm_flags = [],
       scalac_provider = ctx.attr._scalac[_ScalacProvider])
 
-  return java_common.create_provider(
-      use_ijar = False,
-      source_jars = [scrooge_jar],
-      compile_time_jars = depset(
-          [output], transitive = [merged_deps.compile_jars]),
-      transitive_compile_time_jars = depset(
-          [output], transitive = [merged_deps.transitive_compile_time_jars]),
-      transitive_runtime_jars = depset(
-          [output], transitive = [merged_deps.transitive_runtime_jars]))
+  return JavaInfo(
+      source_jar = scrooge_jar,
+      deps = deps_java_info + implicit_deps,
+      runtime_deps = deps_java_info + implicit_deps,
+      exports = deps_java_info + implicit_deps,
+      output_jar = output,
+      compile_jar = output)
 
 def _empty_java_info(deps_java_info, implicit_deps):
   merged_deps = java_common.merge(deps_java_info + implicit_deps)
@@ -334,10 +332,16 @@ def _scrooge_scala_library_impl(ctx):
     all_java = java_common.merge(exports + [aspect_info.java_info])
   else:
     all_java = aspect_info.java_info
-  return [
-      DefaultInfo(files = aspect_info.output_files),
-      ScroogeInfo(aspect_info = aspect_info), all_java
-  ]
+
+  # TODO: Remove `scala` field once JavaInfo supports multiple
+  # output jars. https://github.com/bazelbuild/rules_scala/issues/564
+  return struct(
+      scala = _create_scala_struct(ctx),  # For IntelliJ support
+      providers = [
+          all_java,
+          ScroogeInfo(aspect_info = aspect_info),
+          DefaultInfo(files = aspect_info.output_files)
+      ])
 
 scrooge_scala_library = rule(
     implementation = _scrooge_scala_library_impl,
@@ -348,6 +352,21 @@ scrooge_scala_library = rule(
     provides = [DefaultInfo, ScroogeInfo, JavaInfo],
 )
 
+def _create_scala_struct(ctx):
+  """Create a scala provider in the shape expected by the IntelliJ bazel plugin."""
+  output_jars = []
+
+  for dep in ctx.attr.deps:
+    for j in dep[ScroogeAspectInfo].java_info.outputs.jars:
+      output_jars.append(
+          struct(
+              class_jar = j.class_jar,
+              ijar = None,
+              source_jar = None,
+              source_jars = []))
+
+  return struct(outputs = struct(jars = output_jars))
+
 def _scrooge_scala_import_impl(ctx):
   scala_jars = depset(ctx.files.scala_jars)
   jars_ji = java_common.create_provider(