For Vundle, put the following in your .vimrc and then run :PluginInstall. Customize the binding to your liking.

Plugin 'yuhanfang/vim-rotate-related-files'

noremap \r :call fang#RotateRelatedFiles()<CR>

Rotates between different related files. For example, if you install the plugin with the above binding, then hitting \r while editing foo.xyz will edit foo_test.xyz. Hitting \r while editing foo_test.xyz will edit foo.xyz. Of course, this is only useful if your code follows an opinionated bazel-like layout.

As a specific exception to this rule, C/C++ files are assumed to take the form name.h, name.cc, and name_test.cc.

C++ header and implementation file extensions can be customized as follows:

" Prefer name.h and name.cpp but also find name.H and name.cc, name.C if they
" exist.
let g:fang#c_header_extensions = ["h", "H"]
let g:fang#c_impl_extensions = ["cpp", "cc", "C"]

Tests are assumed to be name_test.xyz or nameTest.xyz by default. This can be customized as follows:

" Prefer name_test.xyz but also find name-test.xyz if it exists.
let g:fang#test_suffixes = ["_test", "-test"]