feat: Add data parameter to app.requestSingleInstanceLock()

docs/api/app.md

@@ -483,6 +483,7 @@ Returns:
 * `event` Event
 * `argv` String[] - An array of the second instance's command line arguments
 * `workingDirectory` String - The second instance's working directory
+* `additionalData` unknown - A JSON object of additional data passed from the second instance
 
 This event will be emitted inside the primary instance of your application
 when a second instance has been executed and calls `app.requestSingleInstanceLock()`.
@@ -931,6 +932,8 @@ app.setJumpList([
 
 ### `app.requestSingleInstanceLock()`
 
+* `additionalData` unknown (optional) - A JSON object containing additional data to send to the first instance.
+
 Returns `Boolean`
 
 The return value of this method indicates whether or not this instance of your
@@ -956,12 +959,16 @@ starts:
 const { app } = require('electron')
 let myWindow = null
 
-const gotTheLock = app.requestSingleInstanceLock()
+const additionalData = { myKey: 'myValue' }
+const gotTheLock = app.requestSingleInstanceLock(additionalData)
 
 if (!gotTheLock) {
   app.quit()
 } else {
-  app.on('second-instance', (event, commandLine, workingDirectory) => {
+  app.on('second-instance', (event, commandLine, workingDirectory, additionalData) => {
+    // Print out data received from the second instance.
+    console.log(additionalData)
+
     // Someone tried to run a second instance, we should focus our window.
     if (myWindow) {
       if (myWindow.isMinimized()) myWindow.restore()

patches/chromium/.patches

@@ -106,3 +106,4 @@ feat_expose_raw_response_headers_from_urlloader.patch
 chore_do_not_use_chrome_windows_in_cryptotoken_webrequestsender.patch
 process_singleton.patch
 fix_expose_decrementcapturercount_in_web_contents_impl.patch
+feat_add_data_parameter_to_processsingleton.patch

shell/browser/api/electron_api_app.cc

@@ -17,6 +17,7 @@
 #include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "base/system/sys_info.h"
+#include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/icon_manager.h"
 #include "chrome/common/chrome_features.h"
@@ -52,6 +53,7 @@
 #include "shell/common/electron_command_line.h"
 #include "shell/common/electron_paths.h"
 #include "shell/common/gin_converters/base_converter.h"
+#include "shell/common/gin_converters/blink_converter.h"
 #include "shell/common/gin_converters/callback_converter.h"
 #include "shell/common/gin_converters/file_path_converter.h"
 #include "shell/common/gin_converters/gurl_converter.h"
@@ -63,6 +65,7 @@
 #include "shell/common/node_includes.h"
 #include "shell/common/options_switches.h"
 #include "shell/common/platform_util.h"
+#include "shell/common/v8_value_serializer.h"
 #include "third_party/abseil-cpp/absl/types/optional.h"
 #include "ui/gfx/image/image.h"
 
@@ -513,17 +516,22 @@ int GetPathConstant(const std::string& name) {
 bool NotificationCallbackWrapper(
     const base::RepeatingCallback<
         void(const base::CommandLine& command_line,
-             const base::FilePath& current_directory)>& callback,
+             const base::FilePath& current_directory,
+             const std::vector<const uint8_t> additional_data)>& callback,
     const base::CommandLine& cmd,
-    const base::FilePath& cwd) {
+    const base::FilePath& cwd,
+    const std::vector<const uint8_t> additional_data) {
   // Make sure the callback is called after app gets ready.
   if (Browser::Get()->is_ready()) {
-    callback.Run(cmd, cwd);
+    callback.Run(cmd, cwd, std::move(additional_data));
   } else {
     scoped_refptr<base::SingleThreadTaskRunner> task_runner(
         base::ThreadTaskRunnerHandle::Get());
-    task_runner->PostTask(
-        FROM_HERE, base::BindOnce(base::IgnoreResult(callback), cmd, cwd));
+
+    // Make a copy of the span so that the data isn't lost.
+    task_runner->PostTask(FROM_HERE,
+                          base::BindOnce(base::IgnoreResult(callback), cmd, cwd,
+                                         std::move(additional_data)));
   }
   // ProcessSingleton needs to know whether current process is quiting.
   return !Browser::Get()->is_shutting_down();
@@ -1069,8 +1077,14 @@ std::string App::GetLocaleCountryCode() {
 }
 
 void App::OnSecondInstance(const base::CommandLine& cmd,
-                           const base::FilePath& cwd) {
-  Emit("second-instance", cmd.argv(), cwd);
+                           const base::FilePath& cwd,
+                           const std::vector<const uint8_t> additional_data) {
+  v8::Isolate* isolate = JavascriptEnvironment::GetIsolate();
+  v8::Locker locker(isolate);
+  v8::HandleScope handle_scope(isolate);
+  v8::Local<v8::Value> data_value =
+      DeserializeV8Value(isolate, std::move(additional_data));
+  Emit("second-instance", cmd.argv(), cwd, data_value);
 }
 
 bool App::HasSingleInstanceLock() const {
@@ -1079,7 +1093,7 @@ bool App::HasSingleInstanceLock() const {
   return false;
 }
 
-bool App::RequestSingleInstanceLock() {
+bool App::RequestSingleInstanceLock(gin::Arguments* args) {
   if (HasSingleInstanceLock())
     return true;
 
@@ -1090,15 +1104,18 @@ bool App::RequestSingleInstanceLock() {
 
   auto cb = base::BindRepeating(&App::OnSecondInstance, base::Unretained(this));
 
+  blink::CloneableMessage additional_data_message;
+  args->GetNext(&additional_data_message);
 #if defined(OS_WIN)
   bool app_is_sandboxed =
       IsSandboxEnabled(base::CommandLine::ForCurrentProcess());
   process_singleton_ = std::make_unique<ProcessSingleton>(
-      program_name, user_dir, app_is_sandboxed,
-      base::BindRepeating(NotificationCallbackWrapper, cb));
+      program_name, user_dir, additional_data_message.encoded_message,
+      app_is_sandboxed, base::BindRepeating(NotificationCallbackWrapper, cb));
 #else
   process_singleton_ = std::make_unique<ProcessSingleton>(
-      user_dir, base::BindRepeating(NotificationCallbackWrapper, cb));
+      user_dir, additional_data_message.encoded_message,
+      base::BindRepeating(NotificationCallbackWrapper, cb));
 #endif
 
   switch (process_singleton_->NotifyOtherProcessOrCreate()) {

shell/browser/api/electron_api_app.h

@@ -189,9 +189,10 @@ class App : public ElectronBrowserClient::Delegate,
   std::string GetLocale();
   std::string GetLocaleCountryCode();
   void OnSecondInstance(const base::CommandLine& cmd,
-                        const base::FilePath& cwd);
+                        const base::FilePath& cwd,
+                        const std::vector<const uint8_t> additional_data);
   bool HasSingleInstanceLock() const;
-  bool RequestSingleInstanceLock();
+  bool RequestSingleInstanceLock(gin::Arguments* args);
   void ReleaseSingleInstanceLock();
   bool Relaunch(gin::Arguments* args);
   void DisableHardwareAcceleration(gin_helper::ErrorThrower thrower);

spec-main/api-app-spec.ts

@@ -207,7 +207,7 @@ describe('app module', () => {
   describe('app.requestSingleInstanceLock', () => {
     it('prevents the second launch of app', async function () {
       this.timeout(120000);
-      const appPath = path.join(fixturesPath, 'api', 'singleton');
+      const appPath = path.join(fixturesPath, 'api', 'singleton-data');
       const first = cp.spawn(process.execPath, [appPath]);
       await emittedOnce(first.stdout, 'data');
       // Start second app when received output.
@@ -218,8 +218,8 @@ describe('app module', () => {
       expect(code1).to.equal(0);
     });
 
-    it('passes arguments to the second-instance event', async () => {
-      const appPath = path.join(fixturesPath, 'api', 'singleton');
+    async function testArgumentPassing (fixtureName: string, expectedSecondInstanceData: unknown) {
+      const appPath = path.join(fixturesPath, 'api', fixtureName);
       const first = cp.spawn(process.execPath, [appPath]);
       const firstExited = emittedOnce(first, 'exit');
 
@@ -236,14 +236,34 @@ describe('app module', () => {
       expect(code2).to.equal(1);
       const [code1] = await firstExited;
       expect(code1).to.equal(0);
-      const data2 = (await data2Promise)[0].toString('ascii');
-      const secondInstanceArgsReceived: string[] = JSON.parse(data2.toString('ascii'));
+      const received = await data2Promise;
+      const [args, additionalData] = received[0].toString('ascii').split('||');
+      const secondInstanceArgsReceived: string[] = JSON.parse(args.toString('ascii'));
+      const secondInstanceDataReceived = JSON.parse(additionalData.toString('ascii'));
 
       // Ensure secondInstanceArgs is a subset of secondInstanceArgsReceived
       for (const arg of secondInstanceArgs) {
         expect(secondInstanceArgsReceived).to.include(arg,
           `argument ${arg} is missing from received second args`);
       }
+      expect(secondInstanceDataReceived).to.be.deep.equal(expectedSecondInstanceData,
+        `received data ${JSON.stringify(secondInstanceDataReceived)} is not equal to expected data ${JSON.stringify(expectedSecondInstanceData)}.`);
+    }
+
+    it('passes arguments to the second-instance event', async () => {
+      const expectedSecondInstanceData = {
+        level: 1,
+        testkey: 'testvalue1',
+        inner: {
+          level: 2,
+          testkey: 'testvalue2'
+        }
+      };
+      await testArgumentPassing('singleton-data', expectedSecondInstanceData);
+    });
+
+    it('passes arguments to the second-instance event no additional data', async () => {
+      await testArgumentPassing('singleton', null);
     });
   });
 

spec/fixtures/api/singleton-data/main.js

@@ -0,0 +1,26 @@
+const { app } = require('electron');
+
+app.whenReady().then(() => {
+  console.log('started'); // ping parent
+});
+
+const obj = {
+  level: 1,
+  testkey: 'testvalue1',
+  inner: {
+    level: 2,
+    testkey: 'testvalue2'
+  }
+};
+const gotTheLock = app.requestSingleInstanceLock(obj);
+
+app.on('second-instance', (event, args, workingDirectory, data) => {
+  setImmediate(() => {
+    console.log([JSON.stringify(args), JSON.stringify(data)].join('||'));
+    app.exit(0);
+  });
+});
+
+if (!gotTheLock) {
+  app.exit(1);
+}

spec/fixtures/api/singleton-data/package.json

@@ -0,0 +1,5 @@
+{
+  "name": "electron-app-singleton-data",
+  "main": "main.js"
+}
+

spec/fixtures/api/singleton/main.js

@@ -6,9 +6,9 @@ app.whenReady().then(() => {
 
 const gotTheLock = app.requestSingleInstanceLock();
 
-app.on('second-instance', (event, args) => {
+app.on('second-instance', (event, args, workingDirectory, data) => {
   setImmediate(() => {
-    console.log(JSON.stringify(args));
+    console.log([JSON.stringify(args), JSON.stringify(data)].join('||'));
     app.exit(0);
   });
 });