Fix resource priority under name collision (#1456)

* Add failing test for resource name duplication

* Topological sort jars (so that the target jar comes first)

fix #1456

* Sort jars by pre-topological sort to preserve leftmost-first guarantee

With topological order, there's no left-to-right order guarantee
https://bazel.build/rules/lib/depset

As a result, `test/shell/test_misc`'s `test_multi_service_manifest`
fails because the order of `exepected_service_manifest.txt` reverses.

scala/private/phases/phase_compile.bzl

@@ -149,7 +149,7 @@ def _phase_compile(
     # TODO: simplify the return values and use provider
     return struct(
         files = depset(out.full_jars),
-        rjars = depset(out.full_jars, transitive = [rjars]),
+        rjars = depset(out.full_jars, transitive = [rjars], order = "preorder"),
         merged_provider = out.merged_provider,
         external_providers = {
             "JavaInfo": out.merged_provider,

test/src/main/scala/scalarules/test/duplicated_resources/child/BUILD

@@ -0,0 +1,12 @@
+load("//scala:scala.bzl", "scala_test")
+
+# https://github.com/bazelbuild/rules_scala/issues/1455
+scala_test(
+    name = "child",
+    size = "small",
+    srcs = ["ScalaLibResourcesDuplicatedTest.scala"],
+    resource_strip_prefix = "test/src/main/scala/scalarules/test/duplicated_resources/child/",
+    resources = ["resource.txt"],
+    unused_dependency_checker_mode = "off",
+    deps = ["//test/src/main/scala/scalarules/test/duplicated_resources/parent"],
+)

test/src/main/scala/scalarules/test/duplicated_resources/child/ScalaLibResourcesDuplicatedTest.scala

@@ -0,0 +1,14 @@
+package scalarules.test.duplicated
+
+import org.scalatest.funsuite._
+
+class ScalaLibResourcesDuplicatedTest extends AnyFunSuite {
+
+  test("Scala library depends on resource + deps that contains same name resources, have higher priority on this target's resource.") {
+    assert(get("/resource.txt") === "I am a text resource from child!\n")
+  }
+
+  private def get(s: String): String =
+    scala.io.Source.fromInputStream(getClass.getResourceAsStream(s)).mkString
+
+}

test/src/main/scala/scalarules/test/duplicated_resources/child/resource.txt

@@ -0,0 +1 @@
+I am a text resource from child!

test/src/main/scala/scalarules/test/duplicated_resources/parent/BUILD

@@ -0,0 +1,8 @@
+load("//scala:scala.bzl", "scala_library")
+
+scala_library(
+    name = "parent",
+    resource_strip_prefix = "test/src/main/scala/scalarules/test/duplicated_resources/parent/",
+    resources = ["resource.txt"],
+    visibility = ["//test/src/main/scala/scalarules/test/duplicated_resources/child:__pkg__"],
+)

test/src/main/scala/scalarules/test/duplicated_resources/parent/resource.txt

@@ -0,0 +1 @@
+I am a text resource from parent!