automake: use dictwatcher (nvim) to invalidate cache

autoload/neomake/configure.vim

@@ -22,6 +22,9 @@ let s:registered_events = []
 " issue #2742).
 let s:need_to_skip_first_textchanged = !has('nvim-0.3.2') && has('patch-8.0.1494') && !has('patch-8.0.1633')
 
+" For debugging/tests.
+let g:neomake#configure#_s = s:
+
 
 " TODO: allow for namespaces, and prefer 'automake' here.
 " TODO: handle bufnr!  (getbufvar)
@@ -548,6 +551,9 @@ function! s:configure_buffer(bufnr, ...) abort
         augroup neomake_automake_clean
             autocmd BufWipeout <buffer> call s:neomake_automake_clean(expand('<abuf>'))
         augroup END
+        if exists('*dictwatcheradd')
+            call dictwatcheradd(b:, 'neomake_*', function('s:dictwatcher_b'))
+        endif
     endif
 
     if implicit_config.ignore
@@ -795,6 +801,39 @@ function! neomake#configure#automake(...) abort
     endif
 endfunction
 
+function! s:maybe_clear_buffer_cache(bufnr) abort
+    if has_key(s:configured_buffers, a:bufnr) && !s:configured_buffers[a:bufnr].custom
+        unlet s:configured_buffers[a:bufnr]
+        return 1
+    endif
+    return 0
+endfunction
+
+if exists('*dictwatcheradd')
+    function! s:dictwatcher(d, k, update) abort
+        if a:k =~# '_enabled_makers$'
+            let cleared = 0
+            for [bufnr, v] in items(s:configured_buffers)
+                if s:maybe_clear_buffer_cache(bufnr)
+                    let cleared += 1
+                endif
+            endfor
+            if cleared
+                call s:debug_log(printf('cleared cached config for %d buffers', cleared))
+            endif
+        endif
+    endfunction
+    function! s:dictwatcher_b(d, k, update) abort
+        if a:k =~# '_enabled_makers$'
+            let bufnr = bufnr('%')
+            if s:maybe_clear_buffer_cache(bufnr)
+                call s:debug_log('cleared cached config for buffer', {'bufnr': bufnr})
+            endif
+        endif
+    endfunction
+    call dictwatcheradd(g:, 'neomake_*', function('s:dictwatcher'))
+endif
+
 augroup neomake_automake_base
     au!
     autocmd FileType * call s:maybe_reconfigure_buffer(expand('<abuf>'))

tests/automake.vader

@@ -297,24 +297,52 @@ Execute (Automake):
   AssertEqual len(g:neomake_test_jobfinished), 4
 
   new
+  let bufnr = bufnr('%')
   exe 'doautocmd' event
   AssertNeomakeMessage 'automake: configured buffer for ft= (no enabled makers).'
   if event ==# 'TextChanged'
     call NeomakeTestsHandleSecondTextChanged()
   endif
   AssertNeomakeMessage 'automake: no enabled makers.'
 
+  " Test behavior with regard to cache when changing settings.
   let b:neomake_automake_enabled_makers = ['foo']
-  doautocmd FileType
-  AssertNeomakeMessage 'automake: configured buffer for ft= (no enabled makers).'
+  if exists('*dictwatcheradd')
+    AssertNeomakeMessage 'automake: cleared cached config for buffer.'
+    exe 'doautocmd' event
+    AssertNeomakeMessage 'automake: configured buffer for ft= (no enabled makers).'
+  else
+    doautocmd FileType
+    AssertNeomakeMessage 'automake: configured buffer for ft= (no enabled makers).'
+  endif
+
   let b:neomake = {'automake': {'enabled_makers': ['configured_maker']}}
+  if exists('*dictwatcheradd')
+    AssertNeomakeMessage 'automake: cleared cached config for buffer.'
+  endif
+
   let n = len(g:neomake_test_messages)
   exe 'doautocmd' event
   let m = len(g:neomake_test_messages)
-  AssertEqual g:neomake_test_messages[n : m], [
-  \ [3, 'automake: handling event '.event.'.', {'bufnr': bufnr('%'), 'winnr': winnr()}],
-  \ [3, 'automake: no enabled makers.', {'bufnr': bufnr('%'), 'winnr': winnr()}],
-  \ ]
+  let winnr = winnr()
+  if exists('*dictwatcheradd')
+    AssertEqual g:neomake_test_messages[n : m], [
+    \ [3, 'Using setting automake.events={''InsertLeave'': {}, ''TextChanged'': {}} from ''global''.', {'bufnr': bufnr, 'winnr': winnr}],
+    \ [3, 'Using setting automake.enabled_makers=[''configured_maker''] from ''buffer''.', {'bufnr': bufnr, 'winnr': winnr}],
+    \ [0, 'Maker not found (for empty filetype): configured_maker.', {'winnr': winnr}],
+    \ [3, 'automake: configured buffer for ft= (no enabled makers).', {'bufnr': bufnr, 'winnr': winnr}],
+    \ [3, 'automake: setting tick for new buffer.', {'bufnr': bufnr, 'winnr': winnr}],
+    \ [3, 'automake: handling event TextChanged.', {'bufnr': bufnr, 'winnr': winnr}],
+    \ [3, 'automake: no enabled makers.', {'bufnr': bufnr, 'winnr': winnr}]
+    \ ]
+    " ACK error message.
+    AssertNeomakeMessage 'Maker not found (for empty filetype): configured_maker.', 0
+  else
+    AssertEqual g:neomake_test_messages[n : m], [
+    \ [3, 'automake: handling event '.event.'.', {'bufnr': bufnr('%'), 'winnr': winnr()}],
+    \ [3, 'automake: no enabled makers.', {'bufnr': bufnr('%'), 'winnr': winnr()}],
+    \ ]
+  endif
 
   call neomake#configure#automake('nw')
   normal! ifoo
@@ -1629,3 +1657,63 @@ Execute (automake: abort automake with manual run):
     AssertEqualQf getloclist(0), expected_loclist
     bwipe!
   endif
+
+Execute (Reconfigures buffers with dictwatcher):
+  new
+  let bufnr = bufnr('%')
+  set filetype=neomake_tests
+  Save g:neomake_test_enabledmakers
+  let g:neomake_test_enabledmakers = [g:entry_maker]
+  call g:NeomakeSetupAutocmdWrappers()
+
+  call neomake#configure#automake('w')
+
+  exe 'w' tempname()
+  AssertNeomakeMessage 'Running makers: entry_maker (auto).', 3
+  AssertEqual len(g:neomake_test_finished), 1
+
+  AssertEqual g:neomake#configure#_s.configured_buffers[bufnr].custom, 0
+
+  Save g:neomake_neomake_tests_enabled_makers
+  let g:neomake_neomake_tests_enabled_makers = []
+  if exists('*dictwatcheradd')
+    AssertNeomakeMessage 'automake: cleared cached config for 1 buffers.', 3
+  endif
+
+  w
+  if exists('*dictwatcheradd')
+    AssertNeomakeMessage 'automake: configured buffer for ft=neomake_tests (no enabled makers).', 3
+    AssertNeomakeMessage 'automake: setting tick for new buffer.', 3
+    AssertNeomakeMessage 'automake: handling event BufWritePost.', 3
+    AssertNeomakeMessage 'automake: no enabled makers.', 3
+  else
+    AssertNeomakeMessage 'automake: handling event BufWritePost.', 3
+    AssertNeomakeMessage 'automake: automake for event BufWritePost.', 3
+    AssertNeomakeMessage 'automake: neomake_do_automake: BufWritePost.', 3
+    AssertNeomakeMessage 'automake: tick is unchanged.', 3
+    AssertNeomakeMessage 'automake: buffer was not changed.', 3
+  endif
+  AssertEqual len(g:neomake_test_finished), 1
+
+  let b:neomake_neomake_tests_enabled_makers = [g:entry_maker]
+  if exists('*dictwatcheradd')
+    AssertNeomakeMessage 'automake: cleared cached config for buffer.', 3
+  endif
+
+  w
+  if exists('*dictwatcheradd')
+    AssertNeomakeMessage 'automake: configured buffer for ft=neomake_tests (entry_maker (default)).', 3
+    AssertNeomakeMessage 'automake: setting tick for new buffer.', 3
+    AssertNeomakeMessage 'automake: handling event BufWritePost.', 3
+    AssertNeomakeMessage 'automake: enabled makers: entry_maker.', 3
+    AssertEqual len(g:neomake_test_finished), 2
+  else
+    AssertNeomakeMessage 'automake: handling event BufWritePost.', 3
+    AssertNeomakeMessage 'automake: automake for event BufWritePost.', 3
+    AssertNeomakeMessage 'automake: neomake_do_automake: BufWritePost.', 3
+    AssertNeomakeMessage 'automake: tick is unchanged.', 3
+    AssertNeomakeMessage 'automake: buffer was not changed.', 3
+    AssertEqual len(g:neomake_test_finished), 1
+  endif
+
+  bwipe