Report JSC errors as JS exceptions

Summary:When JSC throws an error on startup (e.g. a SyntaxError) or when invoking a method that is not caught by RCTExceptionsManager, we previously just reported is a native error, with a (useless) native stack trace in the redbox. This changes that behaviour to report a JS stacktrace.

The same issue was previously reported here: https://github.com/facebook/react-native/pull/5677

Reviewed By: majak

Differential Revision: D3037387

fb-gh-sync-id: 06f8333e0eb50dcef0b26284754262301b8a5f08
fbshipit-source-id: 06f8333e0eb50dcef0b26284754262301b8a5f08

React/Base/RCTBatchedBridge.m

@@ -23,6 +23,7 @@
 #import "RCTProfile.h"
 #import "RCTSourceCode.h"
 #import "RCTUtils.h"
+#import "RCTRedBox.h"
 
 #define RCTAssertJSThread() \
   RCTAssert(![NSStringFromClass([_javaScriptExecutor class]) isEqualToString:@"RCTJSCExecutor"] || \
@@ -506,6 +507,10 @@ RCT_EXTERN NSArray<Class> *RCTGetModuleClasses(void);
    postNotificationName:RCTJavaScriptDidFailToLoadNotification
    object:_parentBridge userInfo:@{@"bridge": self, @"error": error}];
 
+  if ([error userInfo][RCTJSStackTraceKey]) {
+    [self.redBox showErrorMessage:[error localizedDescription]
+                        withStack:[error userInfo][RCTJSStackTraceKey]];
+  }
   RCTFatal(error);
 }
 
@@ -776,21 +781,13 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithBundleURL:(__unused NSURL *)bundleUR
 {
   RCTAssertJSThread();
 
-  RCTJavaScriptCallback processResponse = ^(id json, NSError *error) {
-    if (error) {
-      RCTFatal(error);
-    }
-
-    if (!_valid) {
-      return;
-    }
-    [self handleBuffer:json batchEnded:YES];
-  };
-
+  __weak typeof(self) weakSelf = self;
   [_javaScriptExecutor callFunctionOnModule:module
                                      method:method
                                   arguments:args
-                                   callback:processResponse];
+                                   callback:^(id json, NSError *error) {
+                                     [weakSelf _processResponse:json error:error];
+                                   }];
 }
 
 - (void)_actuallyInvokeCallback:(NSNumber *)cbID
@@ -798,20 +795,28 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithBundleURL:(__unused NSURL *)bundleUR
 {
   RCTAssertJSThread();
 
-  RCTJavaScriptCallback processResponse = ^(id json, NSError *error) {
-    if (error) {
-      RCTFatal(error);
-    }
-
-    if (!_valid) {
-      return;
-    }
-    [self handleBuffer:json batchEnded:YES];
-  };
-
+  __weak typeof(self) weakSelf = self;
   [_javaScriptExecutor invokeCallbackID:cbID
                               arguments:args
-                               callback:processResponse];
+                               callback:^(id json, NSError *error) {
+                                 [weakSelf _processResponse:json error:error];
+                               }];
+}
+
+- (void)_processResponse:(id)json error:(NSError *)error
+{
+  if (error) {
+    if ([error userInfo][RCTJSStackTraceKey]) {
+      [self.redBox showErrorMessage:[error localizedDescription]
+                          withStack:[error userInfo][RCTJSStackTraceKey]];
+    }
+    RCTFatal(error);
+  }
+
+  if (!_valid) {
+    return;
+  }
+  [self handleBuffer:json batchEnded:YES];
 }
 
 #pragma mark - Payload Processing

React/Executors/RCTJSCExecutor.m

@@ -140,9 +140,55 @@ static NSString *RCTJSValueToJSONString(JSContextRef context, JSValueRef value,
 
 static NSError *RCTNSErrorFromJSError(JSContextRef context, JSValueRef jsError)
 {
-  NSString *errorMessage = jsError ? RCTJSValueToNSString(context, jsError, NULL) : @"Unknown JS error";
-  NSString *details = jsError ? RCTJSValueToJSONString(context, jsError, NULL, 2) : @"No details";
-  return [NSError errorWithDomain:@"JS" code:1 userInfo:@{NSLocalizedDescriptionKey: errorMessage, NSLocalizedFailureReasonErrorKey: details}];
+  NSMutableDictionary *errorInfo = [NSMutableDictionary new];
+
+  NSString *description = jsError ? RCTJSValueToNSString(context, jsError, NULL) : @"Unknown JS error";
+  errorInfo[NSLocalizedDescriptionKey] = [@"Unhandled JS Exception: " stringByAppendingString:description];
+
+  NSString *details = jsError ? RCTJSValueToJSONString(context, jsError, NULL, 0) : nil;
+  if (details) {
+    errorInfo[NSLocalizedFailureReasonErrorKey] = details;
+
+    // Format stack as used in RCTFormatError
+    id json = RCTJSONParse(details, NULL);
+    if ([json isKindOfClass:[NSDictionary class]]) {
+      if (json[@"stack"]) {
+        NSError *regexError;
+        NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"^([^@]+)@(.*):(\\d+):(\\d+)$" options:0 error:&regexError];
+        if (regexError) {
+          RCTLogError(@"Failed to build regex: %@", [regexError localizedDescription]);
+        }
+
+        NSMutableArray *stackTrace = [NSMutableArray array];
+        for (NSString *stackLine in [json[@"stack"] componentsSeparatedByString:@"\n"]) {
+          NSTextCheckingResult *result = [regex firstMatchInString:stackLine options:0 range:NSMakeRange(0, stackLine.length)];
+          if (result) {
+            [stackTrace addObject:@{
+              @"methodName": [stackLine substringWithRange:[result rangeAtIndex:1]],
+              @"file": [stackLine substringWithRange:[result rangeAtIndex:2]],
+              @"lineNumber": [stackLine substringWithRange:[result rangeAtIndex:3]],
+              @"column": [stackLine substringWithRange:[result rangeAtIndex:4]]
+            }];
+          }
+        }
+        if ([stackTrace count]) {
+          errorInfo[RCTJSStackTraceKey] = stackTrace;
+        }
+      }
+
+      // Fall back to just logging the line number
+      if (!errorInfo[RCTJSStackTraceKey] && json[@"line"]) {
+        errorInfo[RCTJSStackTraceKey] = @[@{
+          @"methodName": @"",
+          @"file": RCTNullIfNil(json[@"sourceURL"]),
+          @"lineNumber": RCTNullIfNil(json[@"line"]),
+          @"column": @0,
+        }];
+      }
+    }
+  }
+
+  return [NSError errorWithDomain:RCTErrorDomain code:1 userInfo:errorInfo];
 }
 
 #if RCT_DEV
@@ -630,7 +676,7 @@ static void RCTInstallJSCProfiler(RCTBridge *bridge, JSContextRef context)
       RCTLogError(@"%@", errorDesc);
 
       if (onComplete) {
-        NSError *error = [NSError errorWithDomain:@"JS" code:2 userInfo:@{NSLocalizedDescriptionKey: errorDesc}];
+        NSError *error = [NSError errorWithDomain:RCTErrorDomain code:2 userInfo:@{NSLocalizedDescriptionKey: errorDesc}];
         onComplete(error);
       }
       return;

React/Modules/RCTRedBox.m

@@ -103,9 +103,10 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithCoder:(NSCoder *)aDecoder)
   [[[NSURLSession sharedSession] dataTaskWithRequest:request] resume];
 }
 
-- (void)showErrorMessage:(NSString *)message withStack:(NSArray<NSDictionary *> *)stack showIfHidden:(BOOL)shouldShow
+- (void)showErrorMessage:(NSString *)message withStack:(NSArray<NSDictionary *> *)stack isUpdate:(BOOL)isUpdate
 {
-  if ((self.hidden && shouldShow) || (!self.hidden && [_lastErrorMessage isEqualToString:message])) {
+  // Show if this is a new message, or if we're updating the previous message
+  if ((self.hidden && !isUpdate) || (!self.hidden && isUpdate && [_lastErrorMessage isEqualToString:message])) {
     _lastStackTrace = stack;
     // message is displayed using UILabel, which is unable to render text of
     // unlimited length, so we truncate it
@@ -277,7 +278,7 @@ RCT_EXPORT_MODULE()
 
 - (void)showErrorMessage:(NSString *)message
 {
-  [self showErrorMessage:message withStack:nil showIfHidden:YES];
+  [self showErrorMessage:message withStack:nil isUpdate:NO];
 }
 
 - (void)showErrorMessage:(NSString *)message withDetails:(NSString *)details
@@ -291,21 +292,21 @@ RCT_EXPORT_MODULE()
 
 - (void)showErrorMessage:(NSString *)message withStack:(NSArray<NSDictionary *> *)stack
 {
-  [self showErrorMessage:message withStack:stack showIfHidden:YES];
+  [self showErrorMessage:message withStack:stack isUpdate:NO];
 }
 
 - (void)updateErrorMessage:(NSString *)message withStack:(NSArray<NSDictionary *> *)stack
 {
-  [self showErrorMessage:message withStack:stack showIfHidden:NO];
+  [self showErrorMessage:message withStack:stack isUpdate:YES];
 }
 
-- (void)showErrorMessage:(NSString *)message withStack:(NSArray<NSDictionary *> *)stack showIfHidden:(BOOL)shouldShow
+- (void)showErrorMessage:(NSString *)message withStack:(NSArray<NSDictionary *> *)stack isUpdate:(BOOL)isUpdate
 {
   dispatch_async(dispatch_get_main_queue(), ^{
     if (!_window) {
       _window = [[RCTRedBoxWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
     }
-    [_window showErrorMessage:message withStack:stack showIfHidden:shouldShow];
+    [_window showErrorMessage:message withStack:stack isUpdate:isUpdate];
   });
 }