feat(editorconfig): allow editorconfig to be toggled dynamically

Rather than only check `editorconfig_enable` when the plugin is loaded,
check it each time the autocommand fires, so that users may enable or
disable it dynamically.

Also check for a buffer local version of the variable, so that
editorconfig can be enabled or disabled per-buffer.

runtime/plugin/editorconfig.lua

@@ -1,11 +1,14 @@
-if vim.g.editorconfig_enable == false or vim.g.editorconfig_enable == 0 then
-  return
-end
-
 local group = vim.api.nvim_create_augroup('editorconfig', {})
 vim.api.nvim_create_autocmd({ 'BufNewFile', 'BufRead', 'BufFilePost' }, {
   group = group,
   callback = function(args)
+    -- Buffer-local enable has higher priority
+    local enable =
+      vim.F.if_nil(vim.b.editorconfig_enable, vim.F.if_nil(vim.g.editorconfig_enable, true))
+    if not enable then
+      return
+    end
+
     require('editorconfig').config(args.buf)
   end,
 })

test/functional/plugin/editorconfig_spec.lua

@@ -4,6 +4,8 @@ local command = helpers.command
 local eq = helpers.eq
 local pathsep = helpers.get_pathsep()
 local curbufmeths = helpers.curbufmeths
+local funcs = helpers.funcs
+local meths = helpers.meths
 
 local testdir = 'Xtest-editorconfig'
 
@@ -191,4 +193,18 @@ But not this one
   it('sets textwidth', function()
     test_case('max_line_length.txt', { textwidth = 42 })
   end)
+
+  it('can be disabled globally', function()
+    meths.set_var('editorconfig_enable', false)
+    meths.set_option_value('shiftwidth', 42, {})
+    test_case('3_space.txt', { shiftwidth = 42 })
+  end)
+
+  it('can be disabled per-buffer', function()
+    meths.set_option_value('shiftwidth', 42, {})
+    local bufnr = funcs.bufadd(testdir .. pathsep .. '3_space.txt')
+    meths.buf_set_var(bufnr, 'editorconfig_enable', false)
+    test_case('3_space.txt', { shiftwidth = 42 })
+    test_case('4_space.py', { shiftwidth = 4 })
+  end)
 end)