#1108 Support setting b:ale_linter_aliases to a List

autoload/ale/linter.vim

@@ -261,12 +261,19 @@ function! ale#linter#GetAll(filetypes) abort
 endfunction
 
 function! s:GetAliasedFiletype(original_filetype) abort
+    let l:buffer_aliases = get(b:, 'ale_linter_aliases', {})
+
+    " b:ale_linter_aliases can be set to a List.
+    if type(l:buffer_aliases) is type([])
+        return l:buffer_aliases
+    endif
+
     " Check for aliased filetypes first in a buffer variable,
     " then the global variable,
     " then in the default mapping,
     " otherwise use the original filetype.
     for l:dict in [
-    \   get(b:, 'ale_linter_aliases', {}),
+    \   l:buffer_aliases,
     \   g:ale_linter_aliases,
     \   s:default_ale_linter_aliases,
     \]

doc/ale.txt

@@ -906,6 +906,12 @@ g:ale_linter_aliases                                     *g:ale_linter_aliases*
   ALE will first look for aliases for filetypes in the `b:ale_linter_aliases`
   variable, then `g:ale_linter_aliases`, and then a default Dictionary.
 
+  `b:ale_linter_aliases` can be set to a |List|, to tell ALE to load the
+  linters for specific filetypes for a given buffer. >
+
+  let b:ale_linter_aliases = ['html', 'javascript', 'css']
+<
+  No linters will be loaded when the buffer's filetype is empty.
 
 g:ale_linters                                                   *g:ale_linters*
                                                                 *b:ale_linters*

test/test_linter_retrieval.vader

@@ -126,6 +126,21 @@ Execute (The local alias option shouldn't completely replace the global one):
   " global Dictionary.
   let b:ale_linter_aliases = {'testft3': ['testft1']}
 
+Execute (Lists should be accepted for local aliases):
+  call ale#linter#Define('testft1', g:testlinter1)
+  call ale#linter#Define('testft2', g:testlinter2)
+  let g:ale_linter_aliases = {'testft1': ['testft1', 'testft2']}
+  " We should load the testft2 linters for this buffer, with no duplicates.
+  let b:ale_linter_aliases = ['testft2']
+
+  AssertEqual [g:testlinter2], ale#linter#Get('anything.else')
+
+Execute (Buffer-local overrides for aliases should be used):
+  call ale#linter#Define('testft1', g:testlinter1)
+  call ale#linter#Define('testft2', g:testlinter2)
+  let g:ale_linter_aliases = {'testft1': ['testft2']}
+  let b:ale_linter_aliases = {'testft1': ['testft1', 'testft2']}
+
   AssertEqual [g:testlinter1, g:testlinter2], ale#linter#Get('testft1')
 
 Execute (Linters should be loaded from disk appropriately):