Navigate in Neovim b/w source <-> test with :TestNav command.

In ~/.config/nvim/lua/plugins/testnav.vim:

return {
    "eighty4/testnav.vim",
    cmd = {
        "TestNav",
    },
    keys = {
        { "<leader>tn", "<cmd>TestNav<cr>", desc = "Nav b/w source <-> test" },
    },
}

Personal config eighty4/nvim example of Lazy.nvim setup.

• resolve Rust #[cfg(test)] submodules and adjacent #[cfg(test)] mod XXX_test modules
• resolve Flutter test directory