Ignore injected WKWebView messageHandlers errors in Sentry

src/setup/telemetry/setupSentry.ts

@@ -71,6 +71,14 @@ function setupSentry(): void {
             // `add()` instead of `put()` and fails whenever the key is already there. Onyx never calls `add()`, so a
             // real Onyx write cannot produce this, and the DOMException carries no frames to tag as third-party.
             /^ConstraintError: Key already exists in the object store/,
+            // Calls into the WKWebView message bridge an in-app browser injected into the page, which then tore the
+            // bridge down (https://github.com/Expensify/App/issues/100268, Sentry APP-8WS). We ship no
+            // `webkit.messageHandlers` call anywhere in the org, so any error naming one was thrown by injected code
+            // we cannot act on. Filtering on the message rather than the frames is what works here: WebKit withholds
+            // the URL of an injected script, so `denyUrls` and `thirdPartyErrorFilterIntegration` have nothing to
+            // match. The trailing dot keeps this to a real property access into the bridge, so an unrelated error
+            // that merely names the bridge in prose still reports.
+            /webkit\.messageHandlers\./,
         ],
         denyUrls: EXTENSION_DENY_URLS,
         beforeSendTransaction: processBeforeSendTransactions,

tests/unit/setupSentryTest.ts

@@ -70,4 +70,40 @@ describe('setupSentry', () => {
         // Then it still reports
         expect(isIgnored(message)).toBe(false);
     });
+
+    it('drops the WKWebView bridge call an in-app browser injects into the page', () => {
+        // Given the message WebKit builds for the APP-8WS rejection, naming the expression whose base was undefined
+        const message = "TypeError: undefined is not an object (evaluating 'top.webkit.messageHandlers.foregroundToBackground.postMessage')";
+
+        // When the registered patterns are matched against it
+        // Then it is ignored, because no code we ship calls `webkit.messageHandlers`
+        expect(isIgnored(message)).toBe(true);
+    });
+
+    it('drops a call into any other injected handler on that same bridge', () => {
+        // Given the same signature with a different handler name, which is the same injected-bridge noise
+        const message = "TypeError: undefined is not an object (evaluating 'window.webkit.messageHandlers.contextMenuMessageHandler.postMessage')";
+
+        // When the registered patterns are matched against it
+        // Then it is ignored too, rather than needing one pattern per handler name
+        expect(isIgnored(message)).toBe(true);
+    });
+
+    it('keeps an error that only names the bridge in prose, which is not a call into it', () => {
+        // Given an error that mentions the bridge without accessing a handler on it
+        const message = 'Error: Failed to set up webkit.messageHandlers';
+
+        // When the registered patterns are matched against it
+        // Then it still reports, because the trailing dot limits the pattern to a real property access
+        expect(isIgnored(message)).toBe(false);
+    });
+
+    it('keeps the TypeErrors our own code produces, which read the same way in Safari', () => {
+        // Given the same WebKit wording for a property access in our bundle
+        const message = "TypeError: undefined is not an object (evaluating 'policy.employeeList.length')";
+
+        // When the registered patterns are matched against it
+        // Then it still reports
+        expect(isIgnored(message)).toBe(false);
+    });
 });