Allow library tool resource handling to be disabled (#928)

This allows the wrap resource in filegroups and resource bundle
generators to be disabled completely. It allows users to just pass in
`data` and have the rule just forward that to the underlying libraries.

This cleans up the code a bit too since we use `data` directly instead
of `module_data` which had to be converted into a list in a few places.

I added a test showcasing where this ability would be required. It fails
without this change and passes when disabling the library tools

rules/library.bzl

@@ -980,12 +980,18 @@ def apple_library(
         #enable_framework_vfs = enable_framework_vfs
     )
 
-    # Generate resource bundles
-    module_data = library_tools["wrap_resources_in_filegroup"](
-        name = name + "_wrapped_resources_filegroup",
-        srcs = data,
-        testonly = testonly,
-    )
+    # Wrap resources in a filegroup if requested.
+    if library_tools["wrap_resources_in_filegroup"]:
+        # Override the data as all the resources are now wrapped in a single filegroup target
+        data = [
+            library_tools["wrap_resources_in_filegroup"](
+                name = name + "_wrapped_resources_filegroup",
+                srcs = data,
+                testonly = testonly,
+            ),
+        ]
+
+    # Generate resource bundles for any requested `resource_bundles`.
     resource_bundles = library_tools["resource_bundle_generator"](
         name = name,
         library_tools = library_tools,
@@ -1018,7 +1024,7 @@ def apple_library(
                 "@build_bazel_rules_ios//:virtualize_frameworks": ["swift.vfsoverlay"],
                 "//conditions:default": [],
             }),
-            data = [module_data],
+            data = data,
             tags = tags_manual,
             defines = defines + swift_defines,
             testonly = testonly,
@@ -1112,7 +1118,7 @@ def apple_library(
         weak_sdk_frameworks = weak_sdk_frameworks,
         sdk_includes = sdk_includes,
         pch = pch,
-        data = [] if has_swift_sources else [module_data],
+        data = [] if has_swift_sources else data,
         tags = tags_manual,
         defines = defines + objc_defines,
         testonly = testonly,
@@ -1122,7 +1128,7 @@ def apple_library(
     launch_screen_storyboard_name = name + "_launch_screen_storyboard"
     native.filegroup(
         name = launch_screen_storyboard_name,
-        srcs = [module_data],
+        srcs = data,
         output_group = "launch_screen_storyboard",
         tags = _MANUAL,
         testonly = testonly,
@@ -1140,7 +1146,7 @@ def apple_library(
         transitive_deps = deps,
         deps = lib_names + deps,
         module_name = module_name,
-        data = module_data,
+        data = data,
         launch_screen_storyboard_name = launch_screen_storyboard_name,
         namespace = namespace,
         linkopts = copts_by_build_setting.linkopts + linkopts,

tests/ios/frameworks/bundle-in-data-resources/BUILD.bazel

@@ -0,0 +1,29 @@
+load("//rules:framework.bzl", "apple_framework")
+load("//rules:precompiled_apple_resource_bundle.bzl", "precompiled_apple_resource_bundle")
+load("//rules:test.bzl", "ios_unit_test")
+
+precompiled_apple_resource_bundle(
+    name = "BundleInDataResources",
+    bundle_id = "com.example.BundleInDataResources",
+    bundle_name = "BundleInDataResources",
+    platforms = {"ios": "12.0"},
+    resources = ["fake-data.txt"],
+)
+
+apple_framework(
+    name = "BundleInDataResourcesFramework",
+    srcs = ["BundleInData.swift"],
+    data = [":BundleInDataResources"],
+    # Because the `library.bzl` wraps `data` in a filegroup by default, the `rules_apple` aspects
+    # seem to fail to find the resource bundle. It seems in order to directly use a resource bundle rule
+    # within `data`, it must be directly referenced vs. wrapped in a filegroup.
+    library_tools = {"wrap_resources_in_filegroup": None},
+    platforms = {"ios": "12.0"},
+)
+
+ios_unit_test(
+    name = "BundleInDataTests",
+    srcs = ["BundleInDataTests.swift"],
+    minimum_os_version = "12.0",
+    deps = [":BundleInDataResourcesFramework"],
+)

tests/ios/frameworks/bundle-in-data-resources/BundleInData.swift

@@ -0,0 +1,13 @@
+import Foundation
+
+private class BundleInDataBundleFinder {}
+
+// Helper for finding the bundle named "BundleInDataResources"
+public extension Bundle {
+    static let bundleInDataResources: Bundle = {
+        let container = Bundle(for: BundleInDataBundleFinder.self)
+        let bundlePath = container.path(forResource: "BundleInDataResources", ofType: "bundle")!
+        return Bundle(path: bundlePath)!
+    }()
+}
+

tests/ios/frameworks/bundle-in-data-resources/BundleInDataTests.swift

@@ -0,0 +1,17 @@
+import Foundation
+import XCTest
+
+@testable import BundleInDataResourcesFramework
+
+class BundleInDataTests: XCTestCase {
+
+    func testBundleInData() throws {
+        let fakeDataPath = try XCTUnwrap(Bundle.bundleInDataResources.path(forResource: "fake-data", ofType: "txt"))
+        let fakeDataContents = try XCTUnwrap(String(contentsOfFile: fakeDataPath))
+
+        XCTAssertEqual(
+            fakeDataContents,
+            "fake-data\n"
+        )
+    }
+}

tests/ios/frameworks/bundle-in-data-resources/fake-data.txt

@@ -0,0 +1 @@
+fake-data