ScalaTest deps to toolchain

WORKSPACE

@@ -47,6 +47,8 @@ load("//specs2:specs2_junit.bzl", "specs2_junit_repositories")
 
 specs2_junit_repositories()
 
+register_toolchains("//testing:testing_toolchain")
+
 load("//scala/scalafmt:scalafmt_repositories.bzl", "scalafmt_default_config", "scalafmt_repositories")
 
 scalafmt_default_config()

docs/testing.md

@@ -1,10 +1,24 @@
 ## Testing toolchain configuration
 
-Toolchain type `testing_toolchain_type` is used to set up test dependencies. 
+Toolchain type `testing_toolchain_type` is used to set up test dependencies. You can customize
+test dependencies by defining a custom testing toolchain.
+
+In your `WORKSPACE` default repositories and toolchains can be loaded via:
+```starlark
+# JUnit 4
+load("@io_bazel_rules_scala//testing:junit.bzl", "junit_repositories", "junit_toolchain")
+junit_repositories()
+junit_toolchain()
+
+# ScalaTest
+load(""@io_bazel_rules_scala//testing:scalatest.bzl", "scalatest_repositories", "scalatest_toolchain")
+scalatest_repositories()
+scalatest_toolchain()
+```
 
 ### Example to set up JUnit dependencies
 
-`BUILD` file content in your prefered package:
+`BUILD` file content in your preferred package:
 ```starlark
 load("@io_bazel_rules_scala//scala:providers.bzl", "declare_deps_provider")
 load("@io_bazel_rules_scala//testing/toolchain:toolchain.bzl", "scala_testing_toolchain")
@@ -38,8 +52,38 @@ declare_deps_provider(
 `junit_classpath_provider` (deps_id `junit_classpath`) is where classpath required for junit tests
 is defined.
 
-Toolchain must be registerd in your `WORKSPACE` file: 
+ScalaTest support can be enabled by configuring a provider with an id `scalatest_classpath`:
+
+```starlark
+scala_testing_toolchain(
+    name = "testing_toolchains_with_scalatest",
+    dep_providers = [
+        ":scalatest_classpath_provider",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+toolchain(
+    name = "testing_toolchain",
+    toolchain = ":testing_toolchains_with_scalatest",
+    toolchain_type = "@io_bazel_rules_scala//testing/toolchain:testing_toolchain_type",
+    visibility = ["//visibility:public"],
+)
+
+declare_deps_provider(
+    name = "scalatest_classpath_provider",
+    deps_id = "junit_classpath",
+    visibility = ["//visibility:public"],
+    deps = [
+        "@scalactic",
+        "@scalatest",
+    ],
+)
+```
+
+Toolchain must be registered in your `WORKSPACE` file: 
 ```starlark
 register_toolchains('//my/package:testing_toolchain')
 ```
 
+Single toolchain can be used to configure multiple testing rules (JUnit 4, ScalaTest).

junit/junit.bzl

@@ -31,5 +31,3 @@ def junit_repositories(maven_servers = _default_maven_server_urls()):
         name = "io_bazel_rules_scala/dependency/hamcrest/hamcrest_core",
         actual = "@io_bazel_rules_scala_org_hamcrest_hamcrest_core//jar",
     )
-
-    native.register_toolchains("@io_bazel_rules_scala//testing:testing_toolchain")

scala/private/rules/scala_test.bzl

@@ -59,7 +59,7 @@ _scala_test_attrs = {
     "jvm_flags": attr.string_list(),
     "_scalatest": attr.label(
         default = Label(
-            "//external:io_bazel_rules_scala/dependency/scalatest/scalatest",
+            "@io_bazel_rules_scala//testing/toolchain:scalatest_classpath",
         ),
     ),
     "_scalatest_runner": attr.label(
@@ -84,7 +84,7 @@ _test_resolve_deps = {
                 "@io_bazel_rules_scala//scala/private/toolchain_deps:scala_library_classpath",
             ),
             Label(
-                "//external:io_bazel_rules_scala/dependency/scalatest/scalatest",
+                "@io_bazel_rules_scala//testing/toolchain:scalatest_classpath",
             ),
         ],
         allow_files = False,

scala/scalatest/BUILD

@@ -2,11 +2,7 @@ package(default_visibility = ["//visibility:public"])
 
 load("//scala:scala_import.bzl", "scala_import")
 
-scala_import(
+alias(
     name = "scalatest",
-    jars = [],
-    exports = [
-        "//external:io_bazel_rules_scala/dependency/scala/scalactic/scalactic",
-        "//external:io_bazel_rules_scala/dependency/scala/scalatest/scalatest",
-    ],
+    actual = "//testing/toolchain:scalatest_classpath",
 )

scala/support/BUILD

@@ -24,7 +24,7 @@ scala_library(
     ],
     visibility = ["//visibility:public"],
     deps = [
-        "//external:io_bazel_rules_scala/dependency/scalatest/scalatest",
         "//scala/private/toolchain_deps:scala_xml",
+        "//testing/toolchain:scalatest_classpath",
     ],
 )

specs2/specs2_junit.bzl

@@ -4,7 +4,7 @@ load(
     "specs2_repositories",
     "specs2_version",
 )
-load("//junit:junit.bzl", "junit_repositories")
+load("//testing:junit.bzl", "junit_repositories")
 load(
     "//scala:scala_cross_version.bzl",
     _default_maven_server_urls = "default_maven_server_urls",

src/java/io/bazel/rulesscala/scala_test/BUILD

@@ -5,7 +5,7 @@ java_library(
     srcs = ["Runner.java"],
     visibility = ["//visibility:public"],
     deps = [
-        "//external:io_bazel_rules_scala/dependency/scalatest/scalatest",
+        "//testing/toolchain:scalatest_classpath",
         "@bazel_tools//tools/java/runfiles",
     ],
 )

test/aspect/aspect.bzl

@@ -28,7 +28,7 @@ def _rule_impl(ctx):
         "scala_test": [
             "//test/aspect:scala_test",
             "//scala/private/toolchain_deps:scala_library_classpath",
-            "@io_bazel_rules_scala//scala/scalatest:scalatest",
+            "//testing/toolchain:scalatest_classpath",
         ],
         "scala_junit_test": [
             "//test/aspect:scala_junit_test",

test_version/WORKSPACE.template

@@ -54,6 +54,8 @@ load("@io_bazel_rules_scala//specs2:specs2_junit.bzl", "specs2_junit_repositorie
 
 specs2_junit_repositories(scala_version)
 
+register_toolchains("@io_bazel_rules_scala//testing:testing_toolchain")
+
 load("@io_bazel_rules_scala//scala:toolchains.bzl", "scala_register_unused_deps_toolchains")
 
 scala_register_unused_deps_toolchains()

testing/BUILD

@@ -5,6 +5,7 @@ scala_testing_toolchain(
     name = "testing_toolchains_with_all_deps_impl",
     dep_providers = [
         ":junit_classpath_provider",
+        ":scalatest_classpath_provider",
     ],
     visibility = ["//visibility:public"],
 )
@@ -16,6 +17,36 @@ toolchain(
     visibility = ["//visibility:public"],
 )
 
+scala_testing_toolchain(
+    name = "scalatest_toolchain_impl",
+    dep_providers = [
+        ":scalatest_classpath_provider",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+toolchain(
+    name = "scalatest_toolchain",
+    toolchain = ":scalatest_toolchain_impl",
+    toolchain_type = "@io_bazel_rules_scala//testing/toolchain:testing_toolchain_type",
+    visibility = ["//visibility:public"],
+)
+
+scala_testing_toolchain(
+    name = "junit_toolchain_impl",
+    dep_providers = [
+        ":junit_classpath_provider",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+toolchain(
+    name = "junit_toolchain",
+    toolchain = ":junit_toolchain_impl",
+    toolchain_type = "@io_bazel_rules_scala//testing/toolchain:testing_toolchain_type",
+    visibility = ["//visibility:public"],
+)
+
 declare_deps_provider(
     name = "junit_classpath_provider",
     deps_id = "junit_classpath",
@@ -25,3 +56,13 @@ declare_deps_provider(
         "//external:io_bazel_rules_scala/dependency/junit/junit",
     ],
 )
+
+declare_deps_provider(
+    name = "scalatest_classpath_provider",
+    deps_id = "scalatest_classpath",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//external:io_bazel_rules_scala/dependency/scala/scalactic/scalactic",
+        "//external:io_bazel_rules_scala/dependency/scala/scalatest/scalatest",
+    ],
+)

testing/junit.bzl

@@ -0,0 +1,7 @@
+load("//junit:junit.bzl", _repositories = "junit_repositories")
+
+def junit_repositories():
+    _repositories()
+
+def junit_toolchain():
+    native.register_toolchains("@io_bazel_rules_scala//testing:junit_toolchain")

testing/scalatest.bzl

@@ -0,0 +1,6 @@
+def scalatest_repositories():
+    # currently ScalaTest dependencies are already loaded via //scala:scala.bzl#scala_repositories()
+    pass
+
+def scalatest_toolchain():
+    native.register_toolchain("//testing:scalatest_toolchain")

testing/toolchain/BUILD

@@ -10,3 +10,9 @@ testing_toolchain_deps(
     deps_id = "junit_classpath",
     visibility = ["//visibility:public"],
 )
+
+testing_toolchain_deps(
+    name = "scalatest_classpath",
+    deps_id = "scalatest_classpath",
+    visibility = ["//visibility:public"],
+)