fix(apm): Set the transaction name for JavaScript transactions before they are flushed

src/sentry/static/sentry/app/bootstrap.tsx

@@ -26,6 +26,8 @@ import ConfigStore from 'app/stores/configStore';
 import Main from 'app/main';
 import ajaxCsrfSetup from 'app/utils/ajaxCsrfSetup';
 import plugins from 'app/plugins';
+import routes from 'app/routes';
+import {normalizeTransactionName} from 'app/utils/apm';
 
 function getSentryIntegrations(hasReplays: boolean = false) {
   const integrations = [
@@ -74,11 +76,16 @@ const tracesSampleRate = config ? config.apmSampling : 0;
 const hasReplays =
   window.__SENTRY__USER && window.__SENTRY__USER.isStaff && !!process.env.DISABLE_RR_WEB;
 
+const appRoutes = Router.createRoutes(routes());
+
 Sentry.init({
   ...window.__SENTRY__OPTIONS,
   integrations: getSentryIntegrations(hasReplays),
   tracesSampleRate,
   _experiments: {useEnvelope: true},
+  async beforeSend(event) {
+    return normalizeTransactionName(appRoutes, event);
+  },
 });
 
 if (window.__SENTRY__USER) {

src/sentry/static/sentry/app/utils/apm.tsx

@@ -1,4 +1,11 @@
 import * as Sentry from '@sentry/browser';
+import * as Router from 'react-router';
+import {createMemoryHistory} from 'history';
+import set from 'lodash/set';
+
+import getRouteStringFromRoutes from 'app/utils/getRouteStringFromRoutes';
+
+const createLocation = createMemoryHistory().createLocation;
 
 /**
  * Sets the transaction name
@@ -9,3 +16,61 @@ export function setTransactionName(name: string) {
     scope.setTag('ui.route', name);
   });
 }
+
+export async function normalizeTransactionName(
+  appRoutes: Router.PlainRoute[],
+  event: Sentry.Event
+): Promise<Sentry.Event> {
+  if (event.type !== 'transaction') {
+    return event;
+  }
+
+  // For JavaScript transactions, translate the transaction name if it exists and doesn't start with /
+  // using the app's react-router routes. If the transaction name doesn't exist, use the window.location.pathname
+  // as the fallback.
+
+  let prevTransactionName = event.transaction;
+
+  if (typeof prevTransactionName === 'string') {
+    if (prevTransactionName.startsWith('/')) {
+      return event;
+    }
+
+    set(event, ['tags', 'transaction.rename.source'], 'existing transaction name');
+  } else {
+    set(event, ['tags', 'transaction.rename.source'], 'window.location.pathname');
+
+    prevTransactionName = window.location.pathname;
+  }
+
+  const transactionName: string | undefined = await new Promise(function(resolve) {
+    Router.match(
+      {
+        routes: appRoutes,
+        location: createLocation(prevTransactionName),
+      },
+      (error, _redirectLocation, renderProps) => {
+        if (error) {
+          set(event, ['tags', 'transaction.rename.react-router-match'], 'error');
+          return resolve(undefined);
+        }
+
+        set(event, ['tags', 'transaction.rename.react-router-match'], 'success');
+
+        const routePath = getRouteStringFromRoutes(renderProps.routes ?? []);
+        return resolve(routePath);
+      }
+    );
+  });
+
+  if (typeof transactionName === 'string' && transactionName.length) {
+    event.transaction = transactionName;
+
+    set(event, ['tags', 'transaction.rename.before'], prevTransactionName);
+    set(event, ['tags', 'transaction.rename.after'], transactionName);
+
+    set(event, ['tags', 'ui.route'], transactionName);
+  }
+
+  return event;
+}