attempt to insert nil object from objects[0]

아래와 같은 오류가 떴다.

2019-09-04 15:08:46.196386+0900 JeungObjc[5524:730049] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSPlaceholderArray initWithObjects:count:]: attempt to insert nil object from objects[0]'
*** First throw call stack:
(
	0   CoreFoundation                      0x00000001051878db __exceptionPreprocess + 331
	1   libobjc.A.dylib                     0x000000010472aac5 objc_exception_throw + 48
	2   CoreFoundation                      0x00000001050d5fac _CFThrowFormattedException + 194
	3   CoreFoundation                      0x0000000105161a4d -[__NSPlaceholderArray initWithObjects:count:] + 237
	4   CoreFoundation                      0x0000000105176484 +[NSArray arrayWithObjects:count:] + 52
	5   JeungObjc                           0x0000000102900a04 -[TestJS getMessage] + 164
	6   JeungObjc                           0x000000010290080d -[TestJS sendMessage:message:] + 173
	7   CoreFoundation                      0x000000010518e6ac __invoking___ + 140
	8   CoreFoundation                      0x000000010518bc25 -[NSInvocation invoke] + 325
	9   JeungObjc                           0x000000010293bccf -[EasyJSListener userContentController:didReceiveScriptMessage:] + 2143
	10  WebKit                              0x00000001037fdff3 _ZN28ScriptMessageHandlerDelegate14didPostMessageERN6WebKit12WebPageProxyERKNS0_13FrameInfoDataERN7WebCore21SerializedScriptValueE + 213
	11  WebKit                              0x00000001039596cb _ZN6WebKit29WebUserContentControllerProxy14didPostMessageERN3IPC10ConnectionEyRKNS_13FrameInfoDataEyRKNS1_13DataReferenceE + 167
	12  WebKit                              0x0000000103ad2126 _ZN3IPC13handleMessageIN8Messages29WebUserContentControllerProxy14DidPostMessageEN6WebKit29WebUserContentControllerProxyEMS5_FvRNS_10ConnectionEyRKNS4_13FrameInfoDataEyRKNS_13DataReferenceEEEEvS7_RNS_7DecoderEPT0_T1_ + 228
	13  WebKit                              0x00000001036eeb46 _ZN3IPC18MessageReceiverMap15dispatchMessageERNS_10ConnectionERNS_7DecoderE + 126
	14  WebKit                              0x00000001038a7e84 _ZN6WebKit15WebProcessProxy17didReceiveMessageERN3IPC10ConnectionERNS1_7DecoderE + 24
	15  WebKit                              0x00000001036e1a18 _ZN3IPC10Connection15dispatchMessageENSt3__110unique_ptrINS_7DecoderENS1_14default_deleteIS3_EEEE + 108
	16  WebKit                              0x00000001036e44eb _ZN3IPC10Connection24dispatchIncomingMessagesEv + 907
	17  JavaScriptCore                      0x000000010edf32e4 _ZN3WTF7RunLoop11performWorkEv + 228
	18  JavaScriptCore                      0x000000010edf3572 _ZN3WTF7RunLoop11performWorkEPv + 34
	19  CoreFoundation                      0x00000001050eedb1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
	20  CoreFoundation                      0x00000001050ee633 __CFRunLoopDoSources0 + 243
	21  CoreFoundation                      0x00000001050e8cef __CFRunLoopRun + 1231
	22  CoreFoundation                      0x00000001050e84d2 CFRunLoopRunSpecific + 626
	23  GraphicsServices                    0x00000001095332fe GSEventRunModal + 65
	24  UIKitCore                           0x0000000109faafc2 UIApplicationMain + 140
	25  JeungObjc                           0x0000000102900730 main + 112
	26  libdyld.dylib                       0x000000010680e541 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

디버그를 한 줄씩 넘기던 중 아래 코드에서 문제가 생긴다는 걸 알았다.

NSArray라는 언급이 있어서 key와 value 넣는 방식에 문제가 있나 싶어

아래와 같이 변경해보았다.

그랬더니 이번에는 이런 오류가 발생했다.

second object of each pair must be non-nil.  Or, did you forget to nil-terminate your parameter list?

2019-09-04 15:31:08.677590+0900 JeungObjc[5751:814347] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSPlaceholderDictionary initWithObjectsAndKeys:]: second object of each pair must be non-nil.  Or, did you forget to nil-terminate your parameter list?'
*** First throw call stack:
(
	0   CoreFoundation                      0x000000010b5ce8db __exceptionPreprocess + 331
	1   libobjc.A.dylib                     0x000000010ab71ac5 objc_exception_throw + 48
	2   CoreFoundation                      0x000000010b5ca19a -[NSDictionary initWithObjectsAndKeys:] + 1002
	3   JeungObjc                           0x0000000108d47ad1 -[TestJS getMessage] + 145
	4   JeungObjc                           0x0000000108d478ef -[TestJS sendMessage:message:] + 255
	5   CoreFoundation                      0x000000010b5d56ac __invoking___ + 140
	6   CoreFoundation                      0x000000010b5d2c25 -[NSInvocation invoke] + 325
	7   JeungObjc                           0x0000000108d82ccf -[EasyJSListener userContentController:didReceiveScriptMessage:] + 2143
	8   WebKit                              0x0000000109c44ff3 _ZN28ScriptMessageHandlerDelegate14didPostMessageERN6WebKit12WebPageProxyERKNS0_13FrameInfoDataERN7WebCore21SerializedScriptValueE + 213
	9   WebKit                              0x0000000109da06cb _ZN6WebKit29WebUserContentControllerProxy14didPostMessageERN3IPC10ConnectionEyRKNS_13FrameInfoDataEyRKNS1_13DataReferenceE + 167
	10  WebKit                              0x0000000109f19126 _ZN3IPC13handleMessageIN8Messages29WebUserContentControllerProxy14DidPostMessageEN6WebKit29WebUserContentControllerProxyEMS5_FvRNS_10ConnectionEyRKNS4_13FrameInfoDataEyRKNS_13DataReferenceEEEEvS7_RNS_7DecoderEPT0_T1_ + 228
	11  WebKit                              0x0000000109b35b46 _ZN3IPC18MessageReceiverMap15dispatchMessageERNS_10ConnectionERNS_7DecoderE + 126
	12  WebKit                              0x0000000109ceee84 _ZN6WebKit15WebProcessProxy17didReceiveMessageERN3IPC10ConnectionERNS1_7DecoderE + 24
	13  WebKit                              0x0000000109b28a18 _ZN3IPC10Connection15dispatchMessageENSt3__110unique_ptrINS_7DecoderENS1_14default_deleteIS3_EEEE + 108
	14  WebKit                              0x0000000109b2b42d _ZN3IPC10Connection24dispatchIncomingMessagesEv + 717
	15  JavaScriptCore                      0x000000011516f2e4 _ZN3WTF7RunLoop11performWorkEv + 228
	16  JavaScriptCore                      0x000000011516f572 _ZN3WTF7RunLoop11performWorkEPv + 34
	17  CoreFoundation                      0x000000010b535db1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
	18  CoreFoundation                      0x000000010b535633 __CFRunLoopDoSources0 + 243
	19  CoreFoundation                      0x000000010b52fcef __CFRunLoopRun + 1231
	20  CoreFoundation                      0x000000010b52f4d2 CFRunLoopRunSpecific + 626
	21  GraphicsServices                    0x00000001131522fe GSEventRunModal + 65
	22  UIKitCore                           0x000000010f493fc2 UIApplicationMain + 140
	23  JeungObjc                           0x0000000108d477c0 main + 112
	24  libdyld.dylib                       0x000000010cc55541 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

nil로 끝맺는걸 까먹었거나 뭔가 object에 nil이 들어갔다는 말 같아서 살펴보니

세상에.. 이런 실수를 ㅠㅠ

callbackName을 저장하는 함수에서 변수 이름이 똑같아서

정작 멤버변수에 값이 안들어가고 있었던 것... 그러니 nil이지 ㅋㅋㅋ

@interface TestJS() {
    NSMutableString *message;
    NSMutableString *callBackName;
}
@end

멤버변수 이름을 바꾸고 해당 변수를 사용하는 곳에서도 모두 이름을 바뀐대로 바꿔주니 정상 작동한다.