Problem: Some modules are setting empty strings to extraConfig* options
with the intention to not generate any config. But empty
strings are also values, so they are still concatenated in the
final value of extraConfig* options. This results in a
multiple empty strings in extraConfigs.
Solution: Avoid using optionalString when setting values to extraConfig*
options. Use mkIf instead.
This commit also fixes mkIf condition in autocmd module.
`mkNeovimPlugin` is a special case. To avoid evaluating
caller's arguments mkMerge/optionalAttrs pattern is used
instead.
The motivation for this change was to avoid generating empty
config sections like
vim.cmd([[
]])
To make a config generation cleaner several helper functions introduced:
* `hasContent` have been moved to helpers
* `concatNonEmptyLines` joins strings (which has content) separated with
newlines
* `wrapVimscriptForLua` wraps a lua string for using in Vimscript, but
only if the string has content, otherwise empty string is returned
* `wrapLuaForVimscript` wraps Vimscript for using in lua, but only if
the string has content, otherwise empty string is returned
Added tests:
* testing that all possible config sections are present in the final
generated config
* testing that the config files generated by empty `files` definitions
don't have any content in it
This (internal) option introduces IFD, and can be substituted internally
with the `initPath` option easily.
If the content is required somewhere users can use readFile on the
initPath, though it will result in an IFD in their project.
