Support testonly for closure_compile targets in ui/file_manager.

`testonly` ensures that test-only utility files are not depended on by
release files. It also helps when navigating deps in GN's tools.

To cut down on boilerplate, introduce `js_unittest` that automatically
adds testonly = true to js_library and is a better description of these
targets.

Leave "test_support" libraries using js_library + testonly.

Bug: 879035
Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: I5463718ef3f13ead4fd1efae150ff1f7830e43ad
Reviewed-on: https://chromium-review.googlesource.com/c/1275725
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: calamity <calamity@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600200}

BUILD.gn

@@ -1167,6 +1167,7 @@ template("assert_valid_out_dir") {
 
 if (closure_compile) {
   group("webui_closure_compile") {
+    testonly = true
     data_deps = [
       "chrome/browser/resources:closure_compile",
       "content/browser/resources:closure_compile",

third_party/closure_compiler/compile_js.gni

@@ -48,11 +48,12 @@ template("js_library") {
     script = "$script_path/js_library.py"
     forward_variables_from(invoker,
                            [
-                             "sources",
                              "deps",
                              "externs_list",
-                             "extra_sources",
                              "extra_deps",
+                             "extra_sources",
+                             "sources",
+                             "testonly",
                              "visibility",
                            ])
     output_file = "$target_gen_dir/$target_name.js_library"
@@ -146,15 +147,16 @@ template("js_binary") {
     script = "$script_path/js_binary.py"
     forward_variables_from(invoker,
                            [
-                             "sources",
-                             "deps",
-                             "outputs",
                              "bootstrap_file",
-                             "config_files",
+                             "checks_only",
                              "closure_flags",
+                             "config_files",
+                             "deps",
                              "externs_list",
                              "extra_deps",
-                             "checks_only",
+                             "outputs",
+                             "sources",
+                             "testonly",
                            ])
     args = [
       "--compiler",
@@ -237,6 +239,7 @@ template("js_type_check") {
                              [
                                "deps",
                                "closure_flags",
+                               "testonly",
                              ])
     }
   } else {

third_party/closure_compiler/js_unit_tests.gni

@@ -50,6 +50,7 @@ template("js_unit_tests") {
                              "deps",
                              "mocks",
                            ])
+    testonly = true
     sources = []
     foreach(dep, deps) {
       sources += get_target_outputs(dep)
@@ -79,6 +80,7 @@ template("js_unit_tests") {
     type_check_target_name = target_name + "_" + dep + "_type_check"
     type_check_deps += [ ":$type_check_target_name" ]
     js_type_check(type_check_target_name) {
+      testonly = true
       forward_variables_from(invoker, [ "closure_flags" ])
       deps = [
         dep,
@@ -87,12 +89,33 @@ template("js_unit_tests") {
   }
   type_check_group_name = target_name + "_type_check"
   group(type_check_group_name) {
+    testonly = true
     deps = type_check_deps
   }
   group(target_name) {
     data = get_target_outputs(":$html_gen_target_name")
+    testonly = true
     deps = [
       ":$html_gen_target_name",
     ]
   }
 }
+
+# Simple wrapper around js_library to describe a unit test.
+template("js_unittest") {
+  js_library(target_name) {
+    testonly = true
+
+    # Forward everything that js_library forwards except testonly (omitting that
+    # causes gn to emit "Assignment had no effect" if it's added redundantly).
+    forward_variables_from(invoker,
+                           [
+                             "deps",
+                             "externs_list",
+                             "extra_deps",
+                             "extra_sources",
+                             "sources",
+                             "visibility",
+                           ])
+  }
+}

ui/file_manager/BUILD.gn

@@ -30,6 +30,10 @@ component("file_manager") {
 }
 
 group("closure_compile") {
+  # Subfolders' closure_compile groups bundle the non-test "module" type-check
+  # groups as well as unittests and test_support.
+  testonly = true
+
   deps = [
     "audio_player/elements:closure_compile",
     "audio_player/js:closure_compile",
@@ -50,6 +54,7 @@ group("closure_compile") {
 }
 
 group("unit_test_data") {
+  testonly = true
   deps = [
     "file_manager/background/js:unit_tests",
     "file_manager/common/js:unit_tests",

ui/file_manager/base/js/BUILD.gn

@@ -7,6 +7,7 @@ import("//third_party/closure_compiler/compile_js.gni")
 visibility = [ "//ui/file_manager/*" ]
 
 group("closure_compile") {
+  testonly = true
   deps = [
     ":closure_compile_module",
     ":test_support_type_check",
@@ -21,6 +22,7 @@ js_type_check("closure_compile_module") {
 }
 
 js_type_check("test_support_type_check") {
+  testonly = true
   deps = [
     ":mock_chrome",
     ":test_error_reporting",
@@ -45,9 +47,11 @@ js_library("filtered_volume_manager") {
 }
 
 js_library("mock_chrome") {
+  testonly = true
 }
 
 js_library("test_error_reporting") {
+  testonly = true
   deps = [
     # Note we allow targets depending on test_error_reporting to access
     # webui_resource_test transitively.

ui/file_manager/file_manager/background/js/BUILD.gn

@@ -19,6 +19,7 @@ related_apps = [
 ]
 
 group("closure_compile") {
+  testonly = true
   deps = [
     ":closure_compile_module",
     ":unit_tests_type_check",
@@ -305,7 +306,7 @@ js_library("volume_manager_factory") {
   ]
 }
 
-js_library("volume_manager_unittest") {
+js_unittest("volume_manager_unittest") {
   deps = [
     ":volume_manager_factory",
     "//ui/file_manager/base/js:mock_chrome",

ui/file_manager/file_manager/common/js/BUILD.gn

@@ -9,6 +9,7 @@ import("//third_party/closure_compiler/js_unit_tests.gni")
 visibility = [ "//ui/file_manager/*" ]
 
 group("closure_compile") {
+  testonly = true
   deps = [
     ":closure_compile_module",
     ":test_support_type_check",
@@ -34,6 +35,7 @@ js_type_check("closure_compile_module") {
 }
 
 js_type_check("test_support_type_check") {
+  testonly = true
   deps = [
     ":test_importer_common",
     ":unittest_util",
@@ -43,7 +45,7 @@ js_type_check("test_support_type_check") {
 js_library("async_util") {
 }
 
-js_library("async_util_unittest") {
+js_unittest("async_util_unittest") {
   deps = [
     ":async_util",
     "//ui/file_manager/base/js:test_error_reporting",
@@ -57,7 +59,7 @@ js_library("files_app_entry_types") {
   externs_list = [ "../../../externs/volume_info.js" ]
 }
 
-js_library("files_app_entry_types_unittest") {
+js_unittest("files_app_entry_types_unittest") {
   deps = [
     ":files_app_entry_types",
     ":volume_manager_common",
@@ -91,6 +93,7 @@ js_library("importer_common") {
 }
 
 js_library("test_importer_common") {
+  testonly = true
   deps = [
     ":importer_common",
     ":unittest_util",
@@ -100,7 +103,7 @@ js_library("test_importer_common") {
   visibility = [ "//ui/file_manager/file_manager/*" ]
 }
 
-js_library("importer_common_unittest") {
+js_unittest("importer_common_unittest") {
   deps = [
     ":mock_entry",
     ":test_importer_common",
@@ -113,7 +116,7 @@ js_library("importer_common_unittest") {
 js_library("lru_cache") {
 }
 
-js_library("lru_cache_unittest") {
+js_unittest("lru_cache_unittest") {
   deps = [
     ":lru_cache",
     "//ui/webui/resources/js:webui_resource_test",
@@ -151,7 +154,7 @@ js_library("mock_entry") {
 js_library("progress_center_common") {
 }
 
-js_library("unittest_util") {
+js_unittest("unittest_util") {
   # Only files app tests use this util file.
   visibility = []
   visibility = [ "//ui/file_manager/file_manager/*" ]
@@ -179,7 +182,7 @@ js_library("util") {
   ]
 }
 
-js_library("util_unittest") {
+js_unittest("util_unittest") {
   deps = [
     ":mock_entry",
     ":util",

ui/file_manager/file_manager/foreground/js/BUILD.gn

@@ -576,7 +576,7 @@ js_library("thumbnail_loader") {
   ]
 }
 
-js_library("thumbnail_loader_unittest") {
+js_unittest("thumbnail_loader_unittest") {
   deps = [
     ":thumbnail_loader",
     "../../common/js:mock_entry",
@@ -614,6 +614,7 @@ js_unit_tests("unit_tests") {
 }
 
 group("closure_compile") {
+  testonly = true
   visibility += [ "*" ]
   deps = [
     ":closure_compile_module",

ui/file_manager/gallery/js/BUILD.gn

@@ -43,7 +43,7 @@ js_library("dimmable_ui_controller") {
   ]
 }
 
-js_library("dimmable_ui_controller_unittest") {
+js_unittest("dimmable_ui_controller_unittest") {
   deps = [
     ":dimmable_ui_controller",
     "//ui/webui/resources/js:webui_resource_test",
@@ -58,7 +58,7 @@ js_library("entry_list_watcher") {
   ]
 }
 
-js_library("entry_list_watcher_unittest") {
+js_unittest("entry_list_watcher_unittest") {
   deps = [
     ":entry_list_watcher",
     "../../file_manager/common/js:mock_entry",
@@ -99,7 +99,7 @@ js_library("gallery_data_model") {
   ]
 }
 
-js_library("gallery_data_model_unittest") {
+js_unittest("gallery_data_model_unittest") {
   deps = [
     ":gallery_data_model",
     ":mock_gallery_item",
@@ -120,7 +120,7 @@ js_library("gallery_item") {
   externs_list = [ "../../externs/entry_location.js" ]
 }
 
-js_library("gallery_item_unittest") {
+js_unittest("gallery_item_unittest") {
   deps = [
     ":gallery_item",
     ":mock_gallery_item",
@@ -137,7 +137,7 @@ js_library("gallery_util") {
   ]
 }
 
-js_library("gallery_util_unittest") {
+js_unittest("gallery_util_unittest") {
   deps = [
     ":gallery_util",
     "../../file_manager/common/js:mock_entry",
@@ -168,7 +168,7 @@ js_library("ribbon") {
   ]
 }
 
-js_library("ribbon_unittest") {
+js_unittest("ribbon_unittest") {
   deps = [
     ":ribbon",
   ]
@@ -196,7 +196,7 @@ js_library("slide_mode") {
   externs_list = [ "../../externs/gallery_foreground.js" ]
 }
 
-js_library("slide_mode_unittest") {
+js_unittest("slide_mode_unittest") {
   deps = [
     ":slide_mode",
     "//ui/file_manager/base/js:test_error_reporting",
@@ -229,6 +229,7 @@ js_unit_tests("unit_tests") {
 }
 
 group("closure_compile") {
+  testonly = true
   deps = [
     ":closure_compile_module",
     ":unit_tests_type_check",

ui/file_manager/gallery/js/image_editor/BUILD.gn

@@ -47,7 +47,7 @@ js_library("exif_encoder") {
   externs_list = [ "../../../externs/exif_entry.js" ]
 }
 
-js_library("exif_encoder_unittest") {
+js_unittest("exif_encoder_unittest") {
   deps = [
     ":exif_encoder",
     ":test_util",
@@ -120,7 +120,7 @@ js_library("image_encoder") {
   ]
 }
 
-js_library("image_encoder_unittest") {
+js_unittest("image_encoder_unittest") {
   deps = [
     ":image_encoder",
     ":test_util",
@@ -179,7 +179,7 @@ js_library("image_view") {
   ]
 }
 
-js_library("image_view_unittest") {
+js_unittest("image_view_unittest") {
   deps = [
     ":image_view",
     "..:mock_gallery_item",
@@ -207,6 +207,7 @@ js_unit_tests("unit_tests") {
 }
 
 group("closure_compile") {
+  testonly = true
   deps = [
     ":closure_compile_module",
     ":unit_tests_type_check",

ui/file_manager/image_loader/BUILD.gn

@@ -29,7 +29,7 @@ js_library("background") {
 js_library("cache") {
 }
 
-js_library("cache_unittest") {
+js_unittest("cache_unittest") {
   deps = [
     ":cache",
     ":load_image_request",
@@ -48,7 +48,7 @@ js_library("image_loader") {
   ]
 }
 
-js_library("image_loader_unittest") {
+js_unittest("image_loader_unittest") {
   deps = [
     ":image_loader",
     "//ui/webui/resources/js:webui_resource_test",
@@ -82,7 +82,7 @@ js_library("image_loader_client") {
   ]
 }
 
-js_library("image_loader_client_unittest") {
+js_unittest("image_loader_client_unittest") {
   deps = [
     ":image_loader_client",
     "//ui/file_manager/base/js:test_error_reporting",
@@ -96,7 +96,7 @@ js_library("piex_loader") {
   ]
 }
 
-js_library("piex_loader_unittest") {
+js_unittest("piex_loader_unittest") {
   deps = [
     ":piex_loader",
     "//ui/file_manager/base/js:test_error_reporting",
@@ -133,6 +133,7 @@ js_unit_tests("unit_tests") {
 }
 
 group("closure_compile") {
+  testonly = true
   deps = [
     ":closure_compile_module",
     ":unit_tests_type_check",