Fix a MAJOR bug when loading scripts that call tap into the events of a webpage.

Author: MrBlankCoding

src/GM/gm_bridge.js

@@ -0,0 +1,131 @@
+export class ResourceManager {
+  constructor(resourceContents = {}, resourceURLs = {}) {
+    this.contents = new Map(Object.entries(resourceContents));
+    this.urls = new Map(Object.entries(resourceURLs));
+  }
+
+  getText(resourceName) {
+    return this.contents.get(resourceName) ?? null;
+  }
+
+  getURL(resourceName) {
+    return this.urls.get(resourceName) ?? null;
+  }
+
+  static fromScript(script) {
+    const resourceURLs = {};
+
+    if (Array.isArray(script.resources)) {
+      script.resources.forEach((resource) => {
+        resourceURLs[resource.name] = resource.url;
+      });
+    }
+
+    return new ResourceManager(script.resourceContents || {}, resourceURLs);
+  }
+}
+
+export class GMBridge {
+  static ResourceManager = ResourceManager;
+
+  constructor(scriptId, extensionId, worldType = "MAIN") {
+    this.scriptId = scriptId;
+    this.extensionId = extensionId;
+    this.worldType = worldType;
+    this.messageIdCounter = 0;
+    this.pendingPromises = new Map();
+
+    if (this.worldType === "MAIN") {
+      this.setupMessageListener();
+    }
+  }
+
+  setupMessageListener() {
+    window.addEventListener("message", (event) => {
+      if (!this.isValidResponse(event)) return;
+
+      const { messageId, error, result } = event.data;
+      const promise = this.pendingPromises.get(messageId);
+
+      if (!promise) return;
+
+      if (error) {
+        promise.reject(new Error(error));
+      } else {
+        promise.resolve(result);
+      }
+
+      this.pendingPromises.delete(messageId);
+    });
+  }
+
+  isValidResponse(event) {
+    return (
+      event.source === window &&
+      event.data?.type === "GM_API_RESPONSE" &&
+      event.data.extensionId === this.extensionId &&
+      this.pendingPromises.has(event.data.messageId)
+    );
+  }
+
+  call(action, payload = {}) {
+    const enrichedPayload = { ...payload, scriptId: this.scriptId };
+
+    // Use direct chrome.runtime API if available (ISOLATED world)
+    if (
+      this.worldType === "ISOLATED" &&
+      typeof chrome?.runtime?.sendMessage === "function"
+    ) {
+      return this.callIsolated(action, enrichedPayload);
+    }
+
+    // Fallback to postMessage (MAIN world)
+    return this.callMain(action, enrichedPayload);
+  }
+
+  callMain(action, payload = {}) {
+    return new Promise((resolve, reject) => {
+      const messageId = `gm_${this.scriptId}_${this.messageIdCounter++}`;
+      this.pendingPromises.set(messageId, { resolve, reject });
+
+      window.postMessage(
+        {
+          type: "GM_API_REQUEST",
+          extensionId: this.extensionId,
+          messageId,
+          action,
+          payload,
+        },
+        "*"
+      );
+    });
+  }
+
+  callIsolated(action, payload = {}) {
+    return new Promise((resolve, reject) => {
+      try {
+        chrome.runtime.sendMessage(
+          {
+            type: "GM_API_REQUEST",
+            payload: { action, ...payload },
+          },
+          (response) => {
+            if (chrome.runtime.lastError) {
+              reject(new Error(chrome.runtime.lastError.message));
+              return;
+            }
+
+            if (response?.error) {
+              reject(new Error(response.error));
+              return;
+            }
+
+            resolve(response?.result);
+          }
+        );
+      } catch (error) {
+        reject(error);
+      }
+    });
+  }
+}