rb_binary: include only wrapper script in default outputs

without this, it is not possible to reliably locate (via runfiles
library or make variables) the executable output of a rb_binary target
from another target using it as a data dependency, e.g. a shell script.
adds an example of such a case to the 'gem' example workspace.

additionally try to avoid converting depsets to lists when possible

examples/gem/BUILD

@@ -1,3 +1,7 @@
+load("@aspect_bazel_lib//lib:expand_template.bzl", "expand_template")
+load("@aspect_bazel_lib//lib:paths.bzl", "BASH_RLOCATION_FUNCTION")
+
+
 load(
     "@rules_ruby//ruby:defs.bzl",
     "rb_binary",
@@ -9,6 +13,31 @@ load(
 
 package(default_visibility = ["//:__subpackages__"])
 
+expand_template(
+    name = "shell_wrapper",
+    template = "wrapper.tpl.sh",
+    out = "wrapper.sh",
+    substitutions = {
+        "@@rlocation_lib@@": BASH_RLOCATION_FUNCTION.replace("$", "$$"),
+        "@@rake_binary@@": "$(rlocationpaths :rake)",
+        "@@rakefile@@": "$(rlocationpaths :Rakefile)",
+    },
+    data = [
+        ":rake",
+        ":Rakefile",
+    ],
+)
+
+sh_test(
+    name = "shell_wrapper_test",
+    srcs = [":shell_wrapper"],
+    deps = ["@bazel_tools//tools/bash/runfiles"],
+    data = [
+        ":rake",
+        ":Rakefile",
+    ]
+)
+
 rb_binary(
     name = "rake",
     main = "@bundle//bin:rake",

examples/gem/MODULE.bazel

@@ -1,6 +1,7 @@
 "Bazel dependencies"
 
 bazel_dep(name = "bazel_skylib", version = "1.5.0", dev_dependency = True)
+bazel_dep(name = "aspect_bazel_lib", version = "2.11.0", dev_dependency = True)
 bazel_dep(name = "rules_ruby", version = "0.0.0", dev_dependency = True)
 local_path_override(
     module_name = "rules_ruby",

examples/gem/Rakefile

@@ -0,0 +1,4 @@
+desc "say goodnight to bash"
+task "goodnight" do
+  puts "exit 0"
+end

examples/gem/wrapper.tpl.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+@@rlocation_lib@@
+
+set -euo pipefail
+
+rake_binary_expansion=(@@rake_binary@@)
+
+echo "calling the rake binary"
+rake="$(rlocation @@rake_binary@@)"
+rakefile="$(rlocation @@rakefile@@)"
+"$rake" -f "$rakefile" goodnight
+set -x
+eval "$("$rake" -f "$rakefile" goodnight)"
+set +x
+
+echo "rake failed to fail"
+echo "rlocationpaths for rake binary:"
+printf '  %s\n' "${rake_binary_expansion[@]}"
+exit 1

ruby/private/binary.bzl

@@ -129,13 +129,14 @@ def generate_rb_binary_script(ctx, binary, bundler = False, args = [], env = {},
 # buildifier: disable=function-docstring
 def rb_binary_impl(ctx):
     bundler = False
+    bundler_srcs = []
     env = {}
     java_bin = ""
 
     # TODO: avoid expanding the depset to a list, it may be expensive in a large graph
-    transitive_data = get_transitive_data(ctx.files.data, ctx.attr.deps).to_list()
-    transitive_deps = get_transitive_deps(ctx.attr.deps).to_list()
-    transitive_srcs = get_transitive_srcs(ctx.files.srcs, ctx.attr.deps).to_list()
+    transitive_data = get_transitive_data(ctx.files.data, ctx.attr.deps)
+    transitive_deps = get_transitive_deps(ctx.attr.deps)
+    transitive_srcs = get_transitive_srcs(ctx.files.srcs, ctx.attr.deps)
 
     ruby_toolchain = ctx.toolchains["@rules_ruby//ruby:toolchain_type"]
     if ctx.attr.ruby != None:
@@ -148,28 +149,30 @@ def rb_binary_impl(ctx):
         tools.extend(java_toolchain.java_runtime.files.to_list())
         java_bin = java_toolchain.java_runtime.java_executable_runfiles_path[3:]
 
-    for dep in transitive_deps:
+    for dep in transitive_deps.to_list():
         # TODO: Remove workspace name check together with `rb_bundle()`
         if dep.label.workspace_name.endswith("bundle"):
             bundler = True
 
         if BundlerInfo in dep:
             info = dep[BundlerInfo]
-            transitive_srcs.extend([info.gemfile, info.bin, info.path])
+            bundler_srcs.extend([info.gemfile, info.bin, info.path])
             bundler = True
 
             # See https://bundler.io/v2.5/man/bundle-config.1.html for confiugration keys.
             env.update({
                 "BUNDLE_GEMFILE": _to_rlocation_path(info.gemfile),
                 "BUNDLE_PATH": _to_rlocation_path(info.path),
             })
+    if len(bundler_srcs) > 0:
+         transitive_srcs = depset(bundler_srcs, transitive=[transitive_srcs])
 
     bundle_env = get_bundle_env(ctx.attr.env, ctx.attr.deps)
     env.update(bundle_env)
     env.update(ruby_toolchain.env)
     env.update(ctx.attr.env)
 
-    runfiles = ctx.runfiles(transitive_srcs + transitive_data + tools)
+    runfiles = ctx.runfiles(tools, transitive_files=depset(transitive=[transitive_srcs, transitive_data]))
     runfiles = get_transitive_runfiles(runfiles, ctx.attr.srcs, ctx.attr.deps, ctx.attr.data)
 
     # Propagate executable from source rb_binary() targets.
@@ -188,14 +191,13 @@ def rb_binary_impl(ctx):
     return [
         DefaultInfo(
             executable = script,
-            files = depset(transitive_srcs + transitive_data + tools),
             runfiles = runfiles,
         ),
         RubyFilesInfo(
             binary = executable,
-            transitive_data = depset(transitive_data + tools),
-            transitive_deps = depset(transitive_deps),
-            transitive_srcs = depset(transitive_srcs),
+            transitive_data = depset(tools, transitive=[transitive_data]),
+            transitive_deps = transitive_deps,
+            transitive_srcs = transitive_srcs,
             bundle_env = bundle_env,
         ),
         RunEnvironmentInfo(