Close #1379 - Increment b:ale_linted when a buffer is checked

autoload/ale/engine.vim

@@ -321,6 +321,12 @@ function! ale#engine#SetResults(buffer, loclist) abort
 
         " Reset the save event marker, used for opening windows, etc.
         call setbufvar(a:buffer, 'ale_save_event_fired', 0)
+        " Set a marker showing how many times a buffer has been checked.
+        call setbufvar(
+        \   a:buffer,
+        \   'ale_linted',
+        \   getbufvar(a:buffer, 'ale_linted', 0) + 1
+        \)
 
         " Automatically remove all managed temporary files and directories
         " now that all jobs have completed.

doc/ale.txt

@@ -2280,6 +2280,19 @@ ale#statusline#Count(buffer)                           *ale#statusline#Count()*
   `total`         -> The total number of problems.
 
 
+b:ale_linted                                                     *b:ale_linted*
+
+  `b:ale_linted` is set to the number of times a buffer has been checked by
+  ALE after all linters for one lint cycle have finished checking a buffer.
+  This variable may not be defined until ALE first checks a buffer, so it
+  should be accessed with |get()| or |getbufvar()|. For example: >
+
+    " Print a message indicating how many times ALE has checked this buffer.
+    echo 'ALE has checked this buffer ' . get(b:, 'ale_linted') . ' time(s).'
+    " Print 'checked' using getbufvar() if a buffer has been checked.
+    echo getbufvar(bufnr(''), 'ale_linted', 0) > 0 ? 'checked' : 'not checked'
+<
+
 ALELintPre                                                 *ALELintPre-autocmd*
 ALELintPost                                               *ALELintPost-autocmd*
 

test/test_alelint_autocmd.vader

@@ -3,12 +3,18 @@ Before:
   let g:post_success = 0
   let g:ale_run_synchronously = 1
 
+  unlet! b:ale_linted
+
 After:
   let g:ale_run_synchronously = 0
   let g:ale_buffer_info = {}
-  augroup! VaderTest
 
-Execute (Run a lint cycle, and check that a variable is set in the autocmd):
+  try
+    augroup! VaderTest
+  catch
+  endtry
+
+Execute(Run a lint cycle, and check that a variable is set in the autocmd):
   augroup VaderTest
     autocmd!
     autocmd User ALELintPre let g:pre_success = 1
@@ -19,3 +25,14 @@ Execute (Run a lint cycle, and check that a variable is set in the autocmd):
 
   AssertEqual g:pre_success, 1
   AssertEqual g:post_success, 1
+
+Execute(b:ale_linted should be increased after each lint cycle):
+  AssertEqual get(b:, 'ale_linted'), 0
+
+  call ale#Lint()
+
+  AssertEqual get(b:, 'ale_linted'), 1
+
+  call ale#Lint()
+
+  AssertEqual get(b:, 'ale_linted'), 2