This is an addon for Vim providing support for editing fish scripts.

• Syntax highlighting and filetype detection, of course.
• Automatic indentation based on keywords for control structures.
• Automatic folds for everything that end terminates in fish.
• Code formatting with fish_indent using the gq operator.
• Jumping to file in fish's function path that defines the function under the cursor using the gf command.
• Searching for definitions including sourced files using commands like [i.
• Keyword lookup that includes pages for fish builtins using the K command.
• Completions from fish using the ^X^O command.
• Syntax checking with quickfix using the :make command.
• Improved funced experience using commands like S to instantly start typing commands in the function body.
• Mimics funced when manually creating new functions.
• Automatic formatting of comments.

For everything above to work you need to have fish installed in $PATH and some Vim features turned on. First, tell Vim to use the syntax and filetype functionality, normally in your ~/.vimrc:

syntax enable
filetype plugin indent on

Next, set some options for the fish filetype. You can do this either by prefixing each line with autocmd FileType fish, or by putting them in your own ~/.vim/ftplugin/fish.vim file:

" Set up :make to use fish for syntax checking.
compiler fish

" Set this to have long lines wrap inside comments.
setlocal textwidth=79

" Enable folding of block structures in fish.
setlocal foldmethod=expr

To make the folds more pleasant to work with you might also want to tweak settings like foldlevelstart and foldminlines, which you could do either globally in your ~/.vimrc or locally as described above.

vim-fish ships with:

• Code snippets for UltiSnips
• A syntax checker for Syntastic
• Insertion rules for endwise
• Configuration for commentary
• Patterns for matchit

But you don't have to install any of those to use this addon.

Vim needs a more POSIX compatible shell than fish for certain functionality to work, such as :%!, compressed help pages and many third-party addons. If you use fish as your login shell or launch Vim from fish, you need to set shell to something else in your ~/.vimrc, for example:

if &shell =~# 'fish$'
    set shell=sh
endif

Best do it somewhere at the top, before any addon code is loaded and executed.

Note that this also affects what :sh[ell] launches, so if you care about that you might want to set it to your second best shell instead. If you use Vim in the terminal you could also train yourself to use :st[op] or CTRL-Z instead and then fg in fish to get back to Vim.