Insert current branch name in insert mode in Neovim

Question

I'd like to create a hotkey to insert the current branch name directly in insert mode with the hotkey <C-b>. I use the plugin gitsigns which has a variable vim.b.gitsigns_head containing the current branch but I can't seem to find a way to input it. I figured I need to add something like

vim.keymap.set('i', '<C-b>', vim.b.gitsigns_head)

but I can't find any way to reference and print the variable.

Answer 1

I would do:

vim.keymap.set('i', '<C-b>', 'b:gitsigns_head', {expr = true})

Or if you prefer a "pure" lua version:

lua vim.keymap.set('i', '<C-b>', "luaeval('vim.b.gitsigns_head')", {expr = true})

The {expr = true} makes that the lhs is evaluated instead of used directly as input.