Mastering JavaScript Functional Programming - Second Edition

Using a logging wrapper

The second idea we mentioned is based on the addLogging() function that we wrote in the Logging section of Chapter 6, Producing Functions – Higher-Order Functions. The idea was to wrap a function with some logging functionality so that, on entry, the arguments would be printed and, on exit, the result of the function would be shown:

pipeline2(  addLogging(getDir),   addLogging(filterOdt),   addLogging(count))("/home/fkereki/Documents"));entering getDir: /home/fkereki/Documentsexiting getDir: ...the list of all the files in the directory...entering filterOdt: ...the same list of files...exiting filterOdt: ...the list of files with names ending in odt...entering count: ...the list of files with names ending in odt...