v3's basic structure

v3/data/inject/isolated.js

@@ -0,0 +1,17 @@
+const port = document.createElement('span');
+port.id = 'ua-port-fgTd9n';
+document.documentElement.append(port);
+
+// preferences
+self.prefs = self.prefs || {
+  ua: 'Mozilla/5.0 (Windows NT 6.3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36',
+  uad: true,
+  major: 100,
+  name: 'Google Chrome',
+  mobile: false,
+  platform: 'Windows',
+  architecture: 'x86',
+  bitness: '64',
+  platformVersion: '10.0.0'
+};
+Object.assign(port.dataset, self.prefs);

v3/data/inject/main.js

@@ -0,0 +1,102 @@
+const port = document.getElementById('ua-port-fgTd9n');
+port.remove();
+console.log(12, port);
+
+// overwrite navigator.userAgent
+{
+  const {get} = Object.getOwnPropertyDescriptor(Navigator.prototype, 'userAgent');
+
+  Object.defineProperty(Navigator.prototype, 'userAgent', {
+    get: new Proxy(get, {
+      apply() {
+        return port.dataset.ua;
+      }
+    })
+  });
+}
+
+// overwrite navigator.userAgentData
+if (port.dataset.uad) {
+  self.NavigatorUAData = self.NavigatorUAData || new class NavigatorUAData {
+    brands = [];
+    mobile = false;
+    platform = 'Unknown';
+    toJSON() {
+      return {};
+    }
+    getHighEntropyValues() {
+      return Promise.resolve({});
+    }
+  };
+
+  Object.defineProperty(self.NavigatorUAData.prototype, 'brands', {
+    get: new Proxy(Object.getOwnPropertyDescriptor(self.NavigatorUAData.prototype, 'brands').get, {
+      apply() {
+        return [{
+          brand: port.dataset.name,
+          version: port.dataset.major
+        }, {
+          brand: 'Chromium',
+          version: port.dataset.major
+        }, {
+          brand: 'Not=A?Brand',
+          version: '24'
+        }];
+      }
+    })
+  });
+  Object.defineProperty(self.NavigatorUAData.prototype, 'mobile', {
+    get: new Proxy(Object.getOwnPropertyDescriptor(self.NavigatorUAData.prototype, 'mobile').get, {
+      apply() {
+        return port.dataset.mobile === 'true';
+      }
+    })
+  });
+  Object.defineProperty(self.NavigatorUAData.prototype, 'platform', {
+    get: new Proxy(Object.getOwnPropertyDescriptor(self.NavigatorUAData.prototype, 'platform').get, {
+      apply() {
+        return port.dataset.platform;
+      }
+    })
+  });
+  self.NavigatorUAData.prototype.toJSON = new Proxy(self.NavigatorUAData.prototype.toJSON, {
+    apply(target, self) {
+      return {
+        brands: self.brands,
+        mobile: self.mobile,
+        platform: self.platform
+      };
+    }
+  });
+  self.NavigatorUAData.prototype.getHighEntropyValues = new Proxy(self.NavigatorUAData.prototype.getHighEntropyValues, {
+    apply(target, self, args) {
+      const hints = args[0];
+
+      if (!hints || Array.isArray(hints) === false) {
+        return Promise.reject(Error(`Failed to execute 'getHighEntropyValues' on 'NavigatorUAData'`));
+      }
+
+      const r = self.toJSON();
+
+      if (hints.includes('architecture')) {
+        r.architecture = port.dataset.architecture;
+      }
+      if (hints.includes('bitness')) {
+        r.bitness = port.dataset.bitness;
+      }
+      if (hints.includes('model')) {
+        r.model = '';
+      }
+      if (hints.includes('platformVersion')) {
+        r.platformVersion = port.dataset.platformVersion;
+      }
+      if (hints.includes('uaFullVersion')) {
+        r.uaFullVersion = self.brands[0].version;
+      }
+      if (hints.includes('fullVersionList')) {
+        r.fullVersionList = this.brands;
+      }
+      return Promise.resolve(r);
+    }
+  });
+}