How to add commands from an external script to .vimrc?

Question

I have used this script to be able to highlight results from test reports: https://vim.fandom.com/wiki/Highlight_multiple_words

When using it in Vim, it works fine when I type :Highlight 1 FAILED (For some reason the numpad-keys don't work).

Unfortunately, this is not session persistent, so I tried to add it to my .vimrc:

" auto highlight PASSED, FAILED, ERROR, SKIPPED
:Highlight 1 FAILED
:Highlight 4 ERROR
:Highlight 2 SKIPPED
:Highlight 3 PASSED

I would have expected this to work, but it doesn't. I get these errors when starting Vim:

Error detected while processing /home/wouter/.vimrc:
line  174:
E492: Not an editor command: :Highlight 1 FAILED
line  175:
E492: Not an editor command: :Highlight 4 ERROR
line  176:
E492: Not an editor command: :Highlight 2 SKIPPED
line  177:
E492: Not an editor command: :Highlight 3 PASSED
Press ENTER or type command to continue

What am I doing wrong here?

Answer 1

This happens, because by the time your .vimrc file is being loaded other startup plugin files have not been loaded yet (see :h startup), so Vim does not really know the `:Highlight' command yet.

There are two ways around it:

1. Defer definition of the custom highlighting until the VimEnter autocommand has been triggered. By that time, your custom plugins are already sourced. For that case you would create a customer function like this:

    function MyHighlighting()
      "auto highlight PASSED, FAILED, ERROR, SKIPPED
      :Highlight 1 FAILED
      :Highlight 4 ERROR
      :Highlight 2 SKIPPED
      :Highlight 3 PASSED
    endfu
    
    augroup MyStartup
      au!
      au VimEnter * ++once :call MyHighlighting()
    augroup END

A slightly similar approach is to make use of timer instead of the VimEnter autocommand. But I prefer the simplicity of the VimEnter autocommand.

2. Make use of the :runtime or :source commands to force loading the plugin before:

" Force loading the runtime script:
" Either use :source /absolute/path/to/your/script.vim
" Or use :runtime plugin/script.vim
:ru plugin/highlights.vim
:Highlight 1 FAILED
[...]

This can get a bit more complex, if you want to check that the script plugin/highlights.vim really exists and only if the script exists want to execute those :Highlight commands (e.g. if you use vim on different systems where you not have the script installed everywhere).

You could use an :if glob() (See :h glob()) statement around this to only execute those commands conditionally, when the script actually exists.

Note: you can use the :scriptnames command to check if a script is being sourced.