New global variable for vertical cursor shift on GoIfErr (#347)

New variable will allow to customize exactly where cursor will end
up and allow user to set this exactly how they wish.

This change is backwards compatible as the default is the same
as was the hardcoded value.

Signed-off-by: Krystian Kulgawczuk <29754364+krystian-kulgawczuk@users.noreply.github.com>

README.md

@@ -844,6 +844,7 @@ require('go').setup({
   on_stdout = function(err, data) _, _ = err, data end, -- callback when job started
   on_stderr = function(err, data)  _, _ = err, data  end, -- callback for stderr
   on_exit = function(code, signal, output)  _, _, _ = code, signal, output  end, -- callback for jobexit, output : string
+  iferr_vertical_shift = 4 -- defines where the cursor will end up vertically from the begining of if err statement 
 })
 ```
 

doc/go.txt

@@ -444,6 +444,7 @@ You can setup go.nvim with following options:
   test_runner = "go", -- one of {`go`, `richgo`, `dlv`, `ginkgo`}
   run_in_floaterm = false, -- set to true to run in float window.
   luasnip = false, -- set true to enable included luasnip
+  iferr_vertical_shift = 4 -- defines where the cursor will end up vertically from the begining of if err statement after GoIfErr command
 }
 
 vim:tw=78:ts=8:sts=8:sw=8:ft=help:norl:expandtab

lua/go.lua

@@ -128,6 +128,7 @@ _GO_NVIM_CFG = {
   on_stdout = function(err, data) _, _ = err, data end, -- callback when job started
   on_stderr = function(err, data)  _, _ = err, data  end, -- callback for stderr
   on_exit = function(code, signal, output)  _, _, _ = code, signal, output  end, -- callback for jobexit, output : string
+  iferr_vertical_shift = 4 -- defines where the cursor will end up vertically from the begining of if err statement after GoIfErr command
 }
 
 -- TODO: nvim_{add,del}_user_command  https://github.com/neovim/neovim/pull/16752

lua/go/iferr.lua

@@ -26,7 +26,8 @@ local run = function()
 
   vim.cmd('silent normal! j=2j')
   vfn.setpos('.', pos)
-  vim.cmd('silent normal! 4j')
+  local vertical_shift =  tostring(_GO_NVIM_CFG.iferr_vertical_shift) .. 'j'
+  vim.cmd('silent normal! ' .. vertical_shift)
   --
 
 end