From 485fa5bea9313b45c014b65a1fb8291aa448782e Mon Sep 17 00:00:00 2001
From: Milan Burda <milan.burda@gmail.com>
Date: Wed, 17 Mar 2021 19:23:03 +0100
Subject: [PATCH] feat: add process.contextId used by @electron/remote (#28007)

---
 docs/api/process.md                          | 8 ++++++++
 lib/renderer/init.ts                         | 4 ++++
 lib/sandboxed_renderer/init.ts               | 4 ++++
 spec-main/api-browser-window-spec.ts         | 1 +
 spec-main/fixtures/module/preload-sandbox.js | 3 ++-
 spec/api-process-spec.js                     | 6 ++++++
 6 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/docs/api/process.md b/docs/api/process.md
index ee00672129ff..e4b5c26d550d 100644
--- a/docs/api/process.md
+++ b/docs/api/process.md
@@ -35,6 +35,7 @@ In sandboxed renderers the `process` object contains only a subset of the APIs:
 * `versions`
 * `mas`
 * `windowsStore`
+* `contextId`
 
 ## Events
 
@@ -133,6 +134,13 @@ A `String` representing Electron's version string.
 A `Boolean`. If the app is running as a Windows Store app (appx), this property is `true`,
 for otherwise it is `undefined`.
 
+### `process.contextId` _Readonly_
+
+A `String` (optional) representing a globally unique ID of the current JavaScript context.
+Each frame has its own JavaScript context. When contextIsolation is enabled, the isolated
+world also has a separate JavaScript context.
+This property is only available in the renderer process.
+
 ## Methods
 
 The `process` object has the following methods:
diff --git a/lib/renderer/init.ts b/lib/renderer/init.ts
index c41fa561888d..3bb3c2d6eff7 100644
--- a/lib/renderer/init.ts
+++ b/lib/renderer/init.ts
@@ -39,6 +39,10 @@ require('@electron/internal/common/init');
 // The global variable will be used by ipc for event dispatching
 const v8Util = process._linkedBinding('electron_common_v8_util');
 
+// Expose process.contextId
+const contextId = v8Util.getHiddenValue<string>(global, 'contextId');
+Object.defineProperty(process, 'contextId', { enumerable: true, value: contextId });
+
 const { ipcRendererInternal } = require('@electron/internal/renderer/ipc-renderer-internal');
 const ipcRenderer = require('@electron/internal/renderer/api/ipc-renderer').default;
 
diff --git a/lib/sandboxed_renderer/init.ts b/lib/sandboxed_renderer/init.ts
index a23082ef04ad..f82f0cbe0058 100644
--- a/lib/sandboxed_renderer/init.ts
+++ b/lib/sandboxed_renderer/init.ts
@@ -89,6 +89,10 @@ Object.defineProperty(preloadProcess, 'noDeprecation', {
   }
 });
 
+// Expose process.contextId
+const contextId = v8Util.getHiddenValue<string>(global, 'contextId');
+Object.defineProperty(preloadProcess, 'contextId', { enumerable: true, value: contextId });
+
 process.on('loaded', () => (preloadProcess as events.EventEmitter).emit('loaded'));
 process.on('exit', () => (preloadProcess as events.EventEmitter).emit('exit'));
 (process as events.EventEmitter).on('document-start', () => (preloadProcess as events.EventEmitter).emit('document-start'));
diff --git a/spec-main/api-browser-window-spec.ts b/spec-main/api-browser-window-spec.ts
index bc673855bbfa..957607b85552 100644
--- a/spec-main/api-browser-window-spec.ts
+++ b/spec-main/api-browser-window-spec.ts
@@ -2490,6 +2490,7 @@ describe('BrowserWindow module', () => {
         expect(test.type).to.equal('renderer');
         expect(test.version).to.equal(process.version);
         expect(test.versions).to.deep.equal(process.versions);
+        expect(test.contextId).to.be.a('string');
 
         if (process.platform === 'linux' && test.osSandbox) {
           expect(test.creationTime).to.be.null('creation time');
diff --git a/spec-main/fixtures/module/preload-sandbox.js b/spec-main/fixtures/module/preload-sandbox.js
index 3f216a3e03fb..816b26be2497 100644
--- a/spec-main/fixtures/module/preload-sandbox.js
+++ b/spec-main/fixtures/module/preload-sandbox.js
@@ -42,7 +42,8 @@
         sandboxed: process.sandboxed,
         type: process.type,
         version: process.version,
-        versions: process.versions
+        versions: process.versions,
+        contextId: process.contextId
       };
     }
   } else if (location.href !== 'about:blank') {
diff --git a/spec/api-process-spec.js b/spec/api-process-spec.js
index 6eada5c945fe..802910741322 100644
--- a/spec/api-process-spec.js
+++ b/spec/api-process-spec.js
@@ -115,4 +115,10 @@ describe('process module', () => {
       expect(success).to.be.false();
     });
   });
+
+  describe('process.contextId', () => {
+    it('is a string', () => {
+      expect(process.contextId).to.be.a('string');
+    });
+  });
 });