feat: detect native crashes (#56)

V3RON · web-flow · commit 989d21120d29 · 2026-01-13T11:10:22.000+01:00
Added native crash detection during test execution that automatically detects when the app crashes, skips the current test file, and continues with the next test file after restarting the app.
diff --git a/.nx/version-plans/version-plan-1768297433994.md b/.nx/version-plans/version-plan-1768297433994.md
@@ -0,0 +1,5 @@
+---
+__default__: prerelease
+---
+
+Added native crash detection during test execution that automatically detects when the app crashes, skips the current test file, and continues with the next test file after restarting the app.
diff --git a/packages/bridge/src/server.ts b/packages/bridge/src/server.ts
@@ -19,6 +19,7 @@ export type BridgeServerOptions = {
 export type BridgeServerEvents = {
   ready: (device: DeviceDescriptor) => void;
   event: (event: BridgeEvents) => void;
+  disconnect: () => void;
 };
 
 export type BridgeServer = {
@@ -76,6 +77,7 @@ export const getBridgeServer = async ({
 
       // TODO: Remove channel when connection is closed.
       clients.delete(ws);
+      emitter.emit('disconnect');
     });
 
     group.updateChannels((channels) => {
diff --git a/packages/config/src/types.ts b/packages/config/src/types.ts
@@ -28,6 +28,12 @@ export const ConfigSchema = z
     unstable__skipAlreadyIncludedModules: z.boolean().optional().default(false),
     unstable__enableMetroCache: z.boolean().optional().default(false),
 
+    detectNativeCrashes: z.boolean().optional().default(true),
+    crashDetectionInterval: z
+      .number()
+      .min(100, 'Crash detection interval must be at least 100ms')
+      .default(500),
+
     // Deprecated property - used for migration detection
     include: z.array(z.string()).optional(),
   })
diff --git a/packages/jest/src/crash-monitor.ts b/packages/jest/src/crash-monitor.ts
@@ -0,0 +1,109 @@
+import { HarnessPlatformRunner } from '@react-native-harness/platforms';
+import { BridgeServer } from '@react-native-harness/bridge/server';
+import { NativeCrashError } from './errors.js';
+import { logger } from '@react-native-harness/tools';
+
+export type CrashMonitor = {
+  startMonitoring(testFilePath: string): Promise<never>;
+  stopMonitoring(): void;
+  markIntentionalRestart(): void;
+  clearIntentionalRestart(): void;
+  dispose(): void;
+};
+
+export type CrashMonitorOptions = {
+  interval: number;
+  platformRunner: HarnessPlatformRunner;
+  bridgeServer: BridgeServer;
+};
+
+export const createCrashMonitor = ({
+  interval,
+  platformRunner,
+  bridgeServer,
+}: CrashMonitorOptions): CrashMonitor => {
+  let pollingInterval: NodeJS.Timeout | null = null;
+  let isIntentionalRestart = false;
+  let currentTestFilePath: string | null = null;
+  let rejectFn: ((error: NativeCrashError) => void) | null = null;
+
+  const handleDisconnect = () => {
+    // Verify if it's actually a crash by checking if app is still running
+    if (!isIntentionalRestart && currentTestFilePath) {
+      // Capture the value to avoid it being null when setTimeout callback runs
+      const testFilePath = currentTestFilePath;
+      logger.debug('Bridge disconnected, checking if app crashed');
+      // Use a slight delay to allow the OS to clean up the process
+      setTimeout(async () => {
+        const isRunning = await platformRunner.isAppRunning();
+        if (!isRunning && !isIntentionalRestart && rejectFn) {
+          logger.debug(`Native crash detected during: ${testFilePath}`);
+          rejectFn(new NativeCrashError(testFilePath));
+        }
+      }, 100);
+    }
+  };
+
+  const startMonitoring = (testFilePath: string): Promise<never> => {
+    currentTestFilePath = testFilePath;
+
+    return new Promise<never>((_, reject) => {
+      rejectFn = reject;
+
+      // Listen for bridge disconnect as early indicator
+      bridgeServer.on('disconnect', handleDisconnect);
+
+      // Poll for app running status
+      pollingInterval = setInterval(async () => {
+        // Skip check during intentional restarts
+        if (isIntentionalRestart) {
+          return;
+        }
+
+        try {
+          const isRunning = await platformRunner.isAppRunning();
+
+          if (!isRunning && currentTestFilePath) {
+            logger.debug(
+              `Native crash detected during: ${currentTestFilePath}`
+            );
+            stopMonitoring();
+            reject(new NativeCrashError(currentTestFilePath));
+          }
+        } catch (error) {
+          logger.error('Error checking app status:', error);
+        }
+      }, interval);
+    });
+  };
+
+  const stopMonitoring = () => {
+    if (pollingInterval) {
+      clearInterval(pollingInterval);
+      pollingInterval = null;
+    }
+    bridgeServer.off('disconnect', handleDisconnect);
+    currentTestFilePath = null;
+    rejectFn = null;
+  };
+
+  const markIntentionalRestart = () => {
+    isIntentionalRestart = true;
+  };
+
+  const clearIntentionalRestart = () => {
+    isIntentionalRestart = false;
+  };
+
+  const dispose = () => {
+    stopMonitoring();
+  };
+
+  return {
+    startMonitoring,
+    stopMonitoring,
+    markIntentionalRestart,
+    clearIntentionalRestart,
+    dispose,
+  };
+};
diff --git a/packages/jest/src/errors.ts b/packages/jest/src/errors.ts
@@ -30,3 +30,13 @@ export class MaxAppRestartsError extends HarnessError {
     this.name = 'MaxAppRestartsError';
   }
 }
+
+export class NativeCrashError extends HarnessError {
+  constructor(
+    public readonly testFilePath: string,
+    public readonly lastKnownTest?: string
+  ) {
+    super('The native app crashed during test execution.');
+    this.name = 'NativeCrashError';
+  }
+}
diff --git a/packages/jest/src/harness.ts b/packages/jest/src/harness.ts
@@ -14,11 +14,13 @@ import {
 } from '@react-native-harness/bundler-metro';
 import { InitializationTimeoutError, MaxAppRestartsError } from './errors.js';
 import { Config as HarnessConfig } from '@react-native-harness/config';
+import { createCrashMonitor, CrashMonitor } from './crash-monitor.js';
 
 export type Harness = {
   runTests: BridgeClientFunctions['runTests'];
   restart: () => Promise<void>;
   dispose: () => Promise<void>;
+  crashMonitor: CrashMonitor;
 };
 
 export const waitForAppReady = async (options: {
@@ -135,6 +137,12 @@ const getHarnessInternal = async (
     ]);
   };
 
+  const crashMonitor = createCrashMonitor({
+    interval: config.crashDetectionInterval,
+    platformRunner: platformInstance,
+    bridgeServer: serverBridge,
+  });
+
   if (signal.aborted) {
     await dispose();
 
@@ -157,7 +165,11 @@ const getHarnessInternal = async (
 
   const restart = () =>
     new Promise<void>((resolve, reject) => {
-      serverBridge.once('ready', () => resolve());
+      crashMonitor.markIntentionalRestart();
+      serverBridge.once('ready', () => {
+        crashMonitor.clearIntentionalRestart();
+        resolve();
+      });
       platformInstance.restartApp().catch(reject);
     });
 
@@ -173,6 +185,7 @@ const getHarnessInternal = async (
     },
     restart,
     dispose,
+    crashMonitor,
   };
 };
 
diff --git a/packages/jest/src/index.ts b/packages/jest/src/index.ts
@@ -17,6 +17,7 @@ import { teardown } from './teardown.js';
 import { HarnessError } from '@react-native-harness/tools';
 import { getErrorMessage } from './logs.js';
 import { DeviceNotRespondingError } from '@react-native-harness/bridge';
+import { NativeCrashError } from './errors.js';
 
 class CancelRun extends Error {
   constructor(message?: string) {
@@ -104,17 +105,52 @@ export default class JestHarness implements CallbackTestRunnerInterface {
               }
               isFirstTest = false;
 
-              return onStart(test).then(() =>
-                runHarnessTestFile({
-                  testPath: test.path,
-                  harness,
-                  globalConfig: this.#globalConfig,
-                  projectConfig: test.context.config,
-                })
-              );
+              return onStart(test).then(async () => {
+                if (!harnessConfig.detectNativeCrashes) {
+                  return runHarnessTestFile({
+                    testPath: test.path,
+                    harness,
+                    globalConfig: this.#globalConfig,
+                    projectConfig: test.context.config,
+                  });
+                }
+
+                // Start crash monitoring
+                const crashPromise = harness.crashMonitor.startMonitoring(
+                  test.path
+                );
+
+                try {
+                  const result = await Promise.race([
+                    runHarnessTestFile({
+                      testPath: test.path,
+                      harness,
+                      globalConfig: this.#globalConfig,
+                      projectConfig: test.context.config,
+                    }),
+                    crashPromise,
+                  ]);
+
+                  return result;
+                } finally {
+                  harness.crashMonitor.stopMonitoring();
+                }
+              });
             })
             .then((result) => onResult(test, result))
-            .catch((err) => {
+            .catch(async (err) => {
+              if (err instanceof NativeCrashError) {
+                onFailure(test, {
+                  message: err.message,
+                  stack: '',
+                });
+
+                // Restart the app for the next test file
+                await harness.restart();
+
+                return;
+              }
+
               if (err instanceof DeviceNotRespondingError) {
                 onFailure(test, {
                   message: err.message,
diff --git a/packages/platform-android/src/adb.ts b/packages/platform-android/src/adb.ts
@@ -21,7 +21,13 @@ export const reversePort = async (
   port: number,
   hostPort: number = port
 ): Promise<void> => {
-  await spawn('adb', ['-s', adbId, 'reverse', `tcp:${port}`, `tcp:${hostPort}`]);
+  await spawn('adb', [
+    '-s',
+    adbId,
+    'reverse',
+    `tcp:${port}`,
+    `tcp:${hostPort}`,
+  ]);
 };
 
 export const stopApp = async (
@@ -102,3 +108,17 @@ export const isBootCompleted = async (adbId: string): Promise<boolean> => {
 export const stopEmulator = async (adbId: string): Promise<void> => {
   await spawn('adb', ['-s', adbId, 'emu', 'kill']);
 };
+
+export const isAppRunning = async (
+  adbId: string,
+  bundleId: string
+): Promise<boolean> => {
+  const { stdout } = await spawn('adb', [
+    '-s',
+    adbId,
+    'shell',
+    'pidof',
+    bundleId,
+  ]);
+  return stdout.trim() !== '';
+};
diff --git a/packages/platform-android/src/runner.ts b/packages/platform-android/src/runner.ts
@@ -60,6 +60,9 @@ const getAndroidRunner = async (
     dispose: async () => {
       await adb.stopApp(adbId, parsedConfig.bundleId);
     },
+    isAppRunning: async () => {
+      return await adb.isAppRunning(adbId, parsedConfig.bundleId);
+    },
   };
 };
 
diff --git a/packages/platform-ios/src/instance.ts b/packages/platform-ios/src/instance.ts
@@ -64,6 +64,9 @@ export const getAppleSimulatorPlatformInstance = async (
     dispose: async () => {
       await simctl.stopApp(udid, config.bundleId);
     },
+    isAppRunning: async () => {
+      return await simctl.isAppRunning(udid, config.bundleId);
+    },
   };
 };
 
@@ -101,5 +104,8 @@ export const getApplePhysicalDevicePlatformInstance = async (
     dispose: async () => {
       await devicectl.stopApp(deviceId, config.bundleId);
     },
+    isAppRunning: async () => {
+      return await devicectl.isAppRunning(deviceId, config.bundleId);
+    },
   };
 };
diff --git a/packages/platform-ios/src/xcrun/devicectl.ts b/packages/platform-ios/src/xcrun/devicectl.ts
@@ -151,3 +151,19 @@ export const getDeviceId = async (name: string): Promise<string | null> => {
 
   return device?.identifier ?? null;
 };
+
+export const isAppRunning = async (
+  identifier: string,
+  bundleId: string
+): Promise<boolean> => {
+  const appInfo = await getAppInfo(identifier, bundleId);
+
+  if (!appInfo) {
+    return false;
+  }
+
+  const processes = await getProcesses(identifier);
+  return processes.some((process) =>
+    process.executable.startsWith(appInfo.url)
+  );
+};
diff --git a/packages/platform-ios/src/xcrun/simctl.ts b/packages/platform-ios/src/xcrun/simctl.ts
@@ -120,3 +120,21 @@ export const getSimulatorId = async (
 
   return simulator?.udid ?? null;
 };
+
+export const isAppRunning = async (
+  udid: string,
+  bundleId: string
+): Promise<boolean> => {
+  try {
+    const { stdout } = await spawn('xcrun', [
+      'simctl',
+      'spawn',
+      udid,
+      'launchctl',
+      'list',
+    ]);
+    return stdout.includes(bundleId);
+  } catch {
+    return false;
+  }
+};
diff --git a/packages/platform-vega/src/runner.ts b/packages/platform-vega/src/runner.ts
@@ -38,6 +38,9 @@ const getVegaRunner = async (
     dispose: async () => {
       await kepler.stopApp(deviceId, bundleId);
     },
+    isAppRunning: async () => {
+      return await kepler.isAppRunning(deviceId, bundleId);
+    },
   };
 };
 
diff --git a/packages/platforms/src/types.ts b/packages/platforms/src/types.ts
@@ -3,6 +3,7 @@ export type HarnessPlatformRunner = {
   restartApp: () => Promise<void>;
   stopApp: () => Promise<void>;
   dispose: () => Promise<void>;
+  isAppRunning: () => Promise<boolean>;
 };
 
 export type HarnessPlatform<TConfig = Record<string, unknown>> = {

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +__default__: prerelease
 +---
++
 +Added native crash detection during test execution that automatically detects when the app crashes, skips the current test file, and continues with the next test file after restarting the app.
Original file line number	Diff line number	Diff line change
`@@ -30,3 +30,13 @@ export class MaxAppRestartsError extends HarnessError {`
`30`	`30`	`this.name = 'MaxAppRestartsError';`
`31`	`31`	`}`
`32`	`32`	`}`
	`33`	`+`
	`34`	`+export class NativeCrashError extends HarnessError {`
	`35`	`+ constructor(`
	`36`	`+ public readonly testFilePath: string,`
	`37`	`+ public readonly lastKnownTest?: string`
	`38`	`+ ) {`
	`39`	`+ super('The native app crashed during test execution.');`
	`40`	`+ this.name = 'NativeCrashError';`
	`41`	`+ }`
	`42`	`+}`