Added additional checks for unhandledRejection errors

Author: niemyjski

example/browser/index.js

@@ -117,7 +117,7 @@ const registerEventHandlers = () => {
     .querySelector("#throw-promise-unhandled-rejection")
     .addEventListener("click", () => {
       const promiseFn = () => new Promise(function (_, reject) {
-        switch (Math.floor(Math.random() * 4)) {
+        switch (Math.floor(Math.random() * 5)) {
           case 0:
             reject(0);
             break;
@@ -130,6 +130,8 @@ const registerEventHandlers = () => {
           case 3:
             reject();
             break;
+          case 4:
+            throw new Error("Error thrown from promise");
         }
       });
 

packages/browser/src/plugins/BrowserGlobalHandlerPlugin.ts

@@ -27,12 +27,24 @@ export class BrowserGlobalHandlerPlugin implements IEventPlugin {
 
     window.addEventListener("unhandledrejection", event => {
       let reason: unknown = event.reason;
-      try {
-        const detailReason = (<{ detail?: { reason: string } }>event).detail?.reason;
-        if (detailReason) {
-          reason = detailReason;
-        }
-      } catch (ex) { /* empty */ }
+      if (!(reason instanceof Error)) {
+        try {
+          // Check for reason in legacy CustomEvents (https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent)
+          const detailReason = (<{ detail?: { reason: string } }>event).detail?.reason;
+          if (detailReason) {
+            reason = detailReason;
+          }
+        } catch (ex) { /* empty */ }
+      }
+
+      if (!(reason instanceof Error)) {
+        try {
+          const error = event.reason.error;
+          if (error) {
+            reason = error;
+          }
+        } catch (ex) { /* empty */ }
+      }
 
       const error: Error = toError(reason, "Unhandled rejection")
       void this._client?.submitUnhandledException(error, "onunhandledrejection");

packages/node/src/plugins/NodeGlobalHandlerPlugin.ts

@@ -23,7 +23,7 @@ export class NodeGlobalHandlerPlugin implements IEventPlugin {
       void this._client?.submitUnhandledException(error, "uncaughtException");
     });
 
-    process.addListener("unhandledRejection", (reason: unknown | null | undefined) => {
+    process.addListener("unhandledRejection", (reason: unknown) => {
       const error: Error = toError(reason, "Unhandled rejection")
       void this._client?.submitUnhandledException(error, "unhandledRejection");
     });