From b518aceaa8f738e581e58aacae93514699b5ff8e Mon Sep 17 00:00:00 2001
From: Jonas Strittmatter <40792180+smjonas@users.noreply.github.com>
Date: Tue, 14 Feb 2023 00:04:16 +0100
Subject: feat(filetype): fall back to file extension when matching from
 hashbang (#22140)

If nothing matched in match_from_hashbang, also check the file extension table.
For a hashbang like '#!/bin/env foo', this will set the filetype to 'fooscript'
assuming the filetype for the 'foo' extension is 'fooscript' in the extension
table.
---
 runtime/lua/vim/filetype.lua        |  4 +++-
 runtime/lua/vim/filetype/detect.lua | 11 ++++++++---
 2 files changed, 11 insertions(+), 4 deletions(-)

(limited to 'runtime/lua')

diff --git a/runtime/lua/vim/filetype.lua b/runtime/lua/vim/filetype.lua
index ec568b5b82..ca91f3f402 100644
--- a/runtime/lua/vim/filetype.lua
+++ b/runtime/lua/vim/filetype.lua
@@ -2604,7 +2604,9 @@ function M.match(args)
     -- If the function tries to use the filename that is nil then it will fail,
     -- but this enables checks which do not need a filename to still work.
     local ok
-    ok, ft = pcall(require('vim.filetype.detect').match_contents, contents, name)
+    ok, ft = pcall(require('vim.filetype.detect').match_contents, contents, name, function(ext)
+      return dispatch(extension[ext], name, bufnr)
+    end)
     if ok and ft then
       return ft
     end
diff --git a/runtime/lua/vim/filetype/detect.lua b/runtime/lua/vim/filetype/detect.lua
index edffdde9c7..b3d9fedeae 100644
--- a/runtime/lua/vim/filetype/detect.lua
+++ b/runtime/lua/vim/filetype/detect.lua
@@ -1420,7 +1420,7 @@ local patterns_hashbang = {
 
 ---@private
 -- File starts with "#!".
-local function match_from_hashbang(contents, path)
+local function match_from_hashbang(contents, path, dispatch_extension)
   local first_line = contents[1]
   -- Check for a line like "#!/usr/bin/env {options} bash".  Turn it into
   -- "#!/usr/bin/bash" to make matching easier.
@@ -1473,6 +1473,11 @@ local function match_from_hashbang(contents, path)
       return ft
     end
   end
+
+  -- If nothing matched, check the extension table. For a hashbang like
+  -- '#!/bin/env foo', this will set the filetype to 'fooscript' assuming
+  -- the filetype for the 'foo' extension is 'fooscript' in the extension table.
+  return dispatch_extension(name)
 end
 
 local patterns_text = {
@@ -1652,10 +1657,10 @@ local function match_from_text(contents, path)
   return cvs_diff(path, contents)
 end
 
-M.match_contents = function(contents, path)
+function M.match_contents(contents, path, dispatch_extension)
   local first_line = contents[1]
   if first_line:find('^#!') then
-    return match_from_hashbang(contents, path)
+    return match_from_hashbang(contents, path, dispatch_extension)
   else
     return match_from_text(contents, path)
   end
-- 
cgit