How to conduct common file tests in elisp

[Harry Putnam]

I'm attempting to look up in the elisp manual how to conduct a
standard file test.

It is not easy to find.

I've tried index search for `file test' <no hits>

Manual search with the common C-s search of the table of contents in
the info manual for `test'.  None of the hits were about file tests.

And finally `s' search which pours through the whole manual on string 
file.*test.. again none of the hits were about standard file tests
like -f file, -d directory, -r file, -x file etc etc.

How is it done?