Objective-C
Information relating to the Objective-C language.
Whereas Objective-C is a cross-platform language, some of this information will be relevant to Mac only.
Logging message send
This article has some very handy information for debugging OS X apps in general, and this in particular:
If you set the NSObjCMessageLoggingEnabled environment variable to "YES", the Objective-C runtime will log all dispatched Objective-C messages to a file named /tmp/msgSends-<pid>.
Unit Testing and Code Coverage
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