From e9f457820079f3982bb54b31a9fc5e30bcf2c021 Mon Sep 17 00:00:00 2001
From: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Date: Sun, 23 Oct 2022 09:51:47 -0300
Subject: [PATCH] feat: implement resources-path flag in shell

---
 docs/api/command-line-switches.md        |  9 +++++++++
 shell/browser/electron_browser_client.cc |  7 +++++++
 shell/common/node_bindings.cc            | 15 +++++++++++++++
 shell/common/options_switches.cc         |  3 +++
 shell/common/options_switches.h          |  1 +
 5 files changed, 35 insertions(+)

diff --git a/docs/api/command-line-switches.md b/docs/api/command-line-switches.md
index e99f223b2f5fc..a207cee74b5a3 100644
--- a/docs/api/command-line-switches.md
+++ b/docs/api/command-line-switches.md
@@ -204,6 +204,15 @@ authentication [per Chromium issue](https://bugs.chromium.org/p/chromium/issues/
 
 Enables remote debugging over HTTP on the specified `port`.
 
+### --resources-path=`path`
+
+Sets the resources path of an Electron application to the specified directory,
+this means that `process.resourcesPath` will point to it. If it's absent or an
+invalid path is passed then it falls back to the default value of the `resources`
+path relative to the Electron binary and emits an error message to the log if
+the path doesn't exist. It's ignored if the application is packaged or the
+`embeddedAsarIntegrityValidation` fuse is enabled.
+
 ### --v=`log_level`
 
 Gives the default maximal active V-logging level; 0 is the default. Normally
diff --git a/shell/browser/electron_browser_client.cc b/shell/browser/electron_browser_client.cc
index 2882575fa3c57..57d90056fd2c9 100644
--- a/shell/browser/electron_browser_client.cc
+++ b/shell/browser/electron_browser_client.cc
@@ -555,6 +555,13 @@ void ElectronBrowserClient::AppendExtraCommandLineSwitches(
       command_line->AppendSwitchPath(switches::kAppPath, app_path);
     }
 
+    base::FilePath resources_path =
+        base::CommandLine::ForCurrentProcess()->GetSwitchValuePath(
+            switches::kResourcesPath);
+    if (!resources_path.empty()) {
+      command_line->AppendSwitchPath(switches::kResourcesPath, resources_path);
+    }
+
     auto env = base::Environment::Create();
     if (env->HasVar("ELECTRON_PROFILE_INIT_SCRIPTS")) {
       command_line->AppendSwitch("profile-electron-init");
diff --git a/shell/common/node_bindings.cc b/shell/common/node_bindings.cc
index b22f0328cd651..33a1297b52e26 100644
--- a/shell/common/node_bindings.cc
+++ b/shell/common/node_bindings.cc
@@ -15,6 +15,7 @@
 #include "base/base_paths.h"
 #include "base/command_line.h"
 #include "base/environment.h"
+#include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "base/run_loop.h"
 #include "base/strings/string_split.h"
@@ -37,6 +38,7 @@
 #include "shell/common/gin_helper/microtasks_scope.h"
 #include "shell/common/mac/main_application_bundle.h"
 #include "shell/common/node_includes.h"
+#include "shell/common/options_switches.h"
 #include "third_party/blink/renderer/bindings/core/v8/v8_initializer.h"  // nogncheck
 #include "third_party/electron_node/src/debug_utils.h"
 
@@ -308,6 +310,19 @@ namespace electron {
 namespace {
 
 base::FilePath GetResourcesPath() {
+  if (!electron::fuses::IsEmbeddedAsarIntegrityValidationEnabled() &&
+      !electron::api::App::IsPackaged()) {
+    base::FilePath resources_path =
+        base::CommandLine::ForCurrentProcess()->GetSwitchValuePath(
+            switches::kResourcesPath);
+    if (!resources_path.empty()) {
+      if (base::PathExists(resources_path)) {
+        return resources_path;
+      }
+      LOG(ERROR) << "--resources-path points to a non-existent directory";
+      resources_path.clear();
+    }
+  }
 #if BUILDFLAG(IS_MAC)
   return MainApplicationBundlePath().Append("Contents").Append("Resources");
 #else
diff --git a/shell/common/options_switches.cc b/shell/common/options_switches.cc
index 57b66f2e2d313..a4e0cc5186120 100644
--- a/shell/common/options_switches.cc
+++ b/shell/common/options_switches.cc
@@ -241,6 +241,9 @@ const char kAppUserModelId[] = "app-user-model-id";
 // The application path
 const char kAppPath[] = "app-path";
 
+// The resources path
+const char kResourcesPath[] = "resources-path";
+
 // The command line switch versions of the options.
 const char kScrollBounce[] = "scroll-bounce";
 
diff --git a/shell/common/options_switches.h b/shell/common/options_switches.h
index b0199569dbcad..90d1d4eb6dba3 100644
--- a/shell/common/options_switches.h
+++ b/shell/common/options_switches.h
@@ -118,6 +118,7 @@ extern const char kCORSSchemes[];
 extern const char kStreamingSchemes[];
 extern const char kAppUserModelId[];
 extern const char kAppPath[];
+extern const char kResourcesPath[];
 
 extern const char kScrollBounce[];
 extern const char kNodeIntegrationInWorker[];