Allow customizing error reports

[paulz]

We are currently reporting handled exception using our custom error handler, which forwards errors to Crashlytics.

Unfortunately this cause our error handler to be reported as a root cause of all errors.

Would it be possible to customize error reporter to exclude our error handler from stack traces?
Or mark it grayed out as FIRCLSUserLogging.m - Line 393 and FIRCLSUserLoggingRecordError + 393

Similar how Bugsnag allows removing modifying stack traces:
https://docs.bugsnag.com/platforms/ios/customizing-error-reports/#modifying-stack-traces

[samedson]

This is a good question @paulz - I think you should be able to get the same behavior using recordExceptionModel:

I'd imaging you're using recordError: right now. Under the hood this calls [NSThread callStackReturnAddresses]; here.

To replicate this behavior using recordExceptionModel:, you can construct the stacktrace, and remove the first N elements:

    let exceptionModel = ExceptionModel(name: "Name", reason: "Reason")
    var stackTrace: [StackFrame] = []

    var addresses = Thread.callStackReturnAddresses;

    // Remove some elements off the top of addresses
    addresses.removeFirst(<N>)

    for address in addresses {
      stackTrace.append(StackFrame(address: address.uintValue))
    }

    exceptionModel.stackTrace = stackTrace

    Crashlytics.crashlytics().record(exceptionModel: exceptionModel)

[paulz]

yes, thank you, @samedson This is a great workaround for now.

At the same time, this takes us under the hood, which brings a list of liabilities:

• future compatibility
• need to test
• added code

Would it be possible to support trimming stack trace as a feature of Crashlytics?

[paulz]

opened issue: #11474

[paulz]

Also seeing that Crashlytics.crashlytics().record(exceptionModel: exceptionModel) goes into completely different path than reportError.

So not sure if we are going to get same error report and what should we write as name and reason?

firebase-ios-sdk/Crashlytics/Crashlytics/Components/FIRCLSUserLogging.m

Lines 354 to 366 in 1ef1ea2

	static void FIRCLSUserLoggingWriteError(FIRCLSFile *file,
	NSError *error,
	NSDictionary<NSString *, id> *additionalUserInfo,
	NSArray *addresses,
	uint64_t timestamp) {
	FIRCLSFileWriteSectionStart(file, "error");
	FIRCLSFileWriteHashStart(file);
	FIRCLSFileWriteHashEntryHexEncodedString(file, "domain", [[error domain] UTF8String]);
	FIRCLSFileWriteHashEntryInt64(file, "code", [error code]);
	FIRCLSFileWriteHashEntryUint64(file, "time", timestamp);
	// addresses
	FIRCLSFileWriteHashKey(file, "stacktrace");

vs

firebase-ios-sdk/Crashlytics/Crashlytics/Handlers/FIRCLSException.mm

Lines 174 to 189 in 1ef1ea2

	void FIRCLSExceptionWrite(FIRCLSFile *file,
	FIRCLSExceptionType type,
	const char *name,
	const char *reason,
	NSArray<FIRStackFrame *> *frames) {
	FIRCLSFileWriteSectionStart(file, "exception");
	FIRCLSFileWriteHashStart(file);
	FIRCLSFileWriteHashEntryString(file, "type", FIRCLSExceptionNameForType(type));
	FIRCLSFileWriteHashEntryHexEncodedString(file, "name", name);
	FIRCLSFileWriteHashEntryHexEncodedString(file, "reason", reason);
	FIRCLSFileWriteHashEntryUint64(file, "time", time(NULL));
	if ([frames count]) {
	FIRCLSFileWriteHashKey(file, "frames");

[samedson]

I think for name you want the error domain, and reason you want the error's description (eg. localizedDescription)

[paulz]

Looks like exception model does not support additional info like error:

- (void)recordError:(NSError *)error userInfo:(NSDictionary<NSString *, id> *)userInfo {
  FIRCLSUserLoggingRecordError(error, userInfo);
}

- (void)recordExceptionModel:(FIRExceptionModel *)exceptionModel {
  FIRCLSExceptionRecordModel(exceptionModel);
}

[samedson]

True - if you want to add userInfo, you can just set custom keys before the error log.