How can I force ALE to treat zsh files as Bourne shell for the purposes of linting

[vincentjorgensen]

Hi! I would like for Vim ALE to treat zsh scripts as bash or sh for the purposes of linting, but I have not figured out how to do that yet. I have two two kinds of zsh scripts, those that end in .zsh and those that have #!/usr/bin/env zsh in the command bang. If I do ALEInfo on a .zsh script, I see:

      Current Filetype: zsh
     Available Linters: ['bashate', 'cspell', 'language_server', 'shell', 'shellcheck']
        Linter Aliases:
     'language_server' -> ['bash-language-server']
       Enabled Linters: ['shell']

But when I test it by unquoting a variable, it does not do anything. Is what I want possible? Thank you!

[krotname]

zsh is already aliased to sh by ALE's default linter aliases, so the alias is probably not the missing part here.

The clue in your :ALEInfo is this line:

Enabled Linters: ['shell']

That is not ShellCheck. It means ALE is using the shell linter path, so diagnostics such as unquoted variables will usually not appear. Enable ShellCheck explicitly and force the dialect you want:

let g:ale_linters = {
\   'zsh': ['shellcheck'],
\}
let g:ale_sh_shellcheck_dialect = 'bash'

Use 'sh' instead of 'bash' if you want POSIX sh rules.

If this is only for one buffer/filetype override, this also works:

let b:ale_linter_aliases = 'sh'
let b:ale_linters = ['shellcheck']
let b:ale_sh_shellcheck_dialect = 'bash'

Then run :ALEInfo again. It should show shellcheck as the enabled/running linter, and the shellcheck executable must be on your PATH.

One caveat: this deliberately asks ShellCheck to parse your zsh files as bash/POSIX shell. That is fine for the style of checks you described, but zsh-specific syntax can produce false positives.

[vincentjorgensen]

Thank you. This accomplishes exactly what I want. I appreciate it!

Question: in the second example:

let b:ale_linter_aliases = 'sh'
let b:ale_linters = ['shellcheck']
let b:ale_sh_shellcheck_dialect = 'bash'

Does this override apply to bash scripts as well and cause ALE to use shellcheck for bash scripts?

[krotname]

No, not globally. The second example uses buffer-local b: variables, so it only affects the buffer where those variables are set.

If you set those lines from a zsh-only ftplugin/autocmd, then only those zsh buffers are aliased to sh and forced to use shellcheck. Bash/sh buffers will keep their own ALE config.

It would affect bash scripts only if you also set the same b: variables in a bash/sh buffer, or if you change the global g:ale_linters / g:ale_linter_aliases settings. In that snippet:

• b:ale_linter_aliases = 'sh' aliases this buffer to ALE's sh linter definitions;
• b:ale_linters = ['shellcheck'] selects ShellCheck for this buffer;
• b:ale_sh_shellcheck_dialect = 'bash' tells the ShellCheck linter to parse this buffer as bash.