Add support for managing temporary files/directories

5 files changed, 169 insertions, 3 deletions

diff --git a/autoload/ale/cleanup.vim b/autoload/ale/cleanup.vim
index 0a1cd391..d720cc96 100644
--- a/autoload/ale/cleanup.vim
+++ b/autoload/ale/cleanup.vim
@@ -3,6 +3,8 @@
 
 function! ale#cleanup#Buffer(buffer) abort
     if has_key(g:ale_buffer_info, a:buffer)
+        call ale#engine#RemoveManagedFiles(a:buffer)
+
         " When buffers are removed, clear all of the jobs.
         for l:job in get(g:ale_buffer_info[a:buffer], 'job_list', [])
             call ale#engine#ClearJob(l:job)
diff --git a/autoload/ale/engine.vim b/autoload/ale/engine.vim
index 70cd0527..22e8ff93 100644
--- a/autoload/ale/engine.vim
+++ b/autoload/ale/engine.vim
@@ -30,10 +30,14 @@ function! ale#engine#InitBufferInfo(buffer) abort
         " job_list will hold the list of jobs
         " loclist holds the loclist items after all jobs have completed.
         " new_loclist holds loclist items while jobs are being run.
+        " temporary_file_list holds temporary files to be cleaned up
+        " temporary_directory_list holds temporary directories to be cleaned up
         let g:ale_buffer_info[a:buffer] = {
         \   'job_list': [],
         \   'loclist': [],
         \   'new_loclist': [],
+        \   'temporary_file_list': [],
+        \   'temporary_directory_list': [],
         \}
     endif
 endfunction
@@ -134,6 +138,40 @@ function! ale#engine#JoinNeovimOutput(output, data) abort
     endif
 endfunction
 
+" Register a temporary file to be managed with the ALE engine for
+" a current job run.
+function! ale#engine#ManageFile(buffer, filename) abort
+    call add(g:ale_buffer_info[a:buffer].temporary_file_list, a:filename)
+endfunction
+
+" Same as the above, but manage an entire directory.
+function! ale#engine#ManageDirectory(buffer, directory) abort
+    call add(g:ale_buffer_info[a:buffer].temporary_directory_list, a:directory)
+endfunction
+
+function! ale#engine#RemoveManagedFiles(buffer) abort
+    if !has_key(g:ale_buffer_info, a:buffer)
+        return
+    endif
+
+    " Delete files with a call akin to a plan `rm` command.
+    for l:filename in g:ale_buffer_info[a:buffer].temporary_file_list
+        call delete(l:filename)
+    endfor
+
+    let g:ale_buffer_info[a:buffer].temporary_file_list = []
+
+    " Delete directories like `rm -rf`.
+    " Directories are handled differently from files, so paths that are
+    " intended to be single files can be set up for automatic deletion without
+    " accidentally deleting entire directories.
+    for l:directory in g:ale_buffer_info[a:buffer].temporary_directory_list
+        call delete(l:directory, 'rf')
+    endfor
+
+    let g:ale_buffer_info[a:buffer].temporary_directory_list = []
+endfunction
+
 function! s:HandleExit(job) abort
     if a:job ==# 'no process'
         " Stop right away when the job is not valid in Vim 8.
@@ -178,6 +216,10 @@ function! s:HandleExit(job) abort
         return
     endif
 
+    " Automatically remove all managed temporary files and directories
+    " now that all jobs have completed.
+    call ale#engine#RemoveManagedFiles(l:buffer)
+
     " Sort the loclist again.
     " We need a sorted list so we can run a binary search against it
     " for efficient lookup of the messages in the cursor handler.
@@ -424,6 +466,10 @@ function! s:InvokeChain(buffer, linter, chain_index, input) abort
 
     if !empty(l:options)
         call s:RunJob(l:options)
+    elseif empty(g:ale_buffer_info[a:buffer].job_list)
+        " If we cancelled running a command, and we have no jobs in progress,
+        " then delete the managed temporary files now.
+        call ale#engine#RemoveManagedFiles(a:buffer)
     endif
 endfunction
 
diff --git a/doc/ale.txt b/doc/ale.txt
index 3ec54d4f..d8f8a4c0 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -1037,6 +1037,35 @@ ale#engine#GetLoclist(buffer)                         *ale#engine#GetLoclist()*
   |setqflist()|.
 
 
+ale#engine#ManageFile(buffer, filename)               *ale#engine#ManageFile()*
+
+  Given a buffer number for a buffer currently running some linting tasks
+  and a filename, register a filename with ALE for automatic deletion after
+  linting is complete, or when Vim exits.
+
+  If Vim exits suddenly, ALE will try its best to remove temporary files, but
+  ALE cannot guarantee with absolute certainty that the files will be removed.
+  It is advised to create temporary files in the operating system's managed
+  temporary file directory, such as with |tempname()|.
+
+  Directory names should not be given to this function. ALE will only delete
+  files and symlinks given to this function. This is to prevent entire
+  directories from being accidentally deleted, say in cases of writing
+  `dir . '/' . filename` where `filename` is actually `''`, etc. ALE instead
+  manages directories separetly with the |ale#engine#ManageDirectory| function.
+
+
+ale#engine#ManageDirectory(buffer, directory)    *ale#engine#ManageDirectory()*
+
+  Like |ale#engine#ManageFile()|, but directories and all of their contents
+  will be deleted, akin to `rm -rf directory`, which could lead to loss of
+  data if mistakes are made. This command will also delete any temporary
+  filenames given to it.
+
+  It is advised to use |ale#engine#ManageFile()| instead for deleting single
+  files.
+
+
 ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
   Given a |String| for a filetype and a |Dictionary| Describing a linter
   configuration, add a linter for the given filetype. The dictionaries each
@@ -1151,6 +1180,12 @@ ale#linter#Define(filetype, linter)                       *ale#linter#Define()*
   `command_chain` is recommended where any system calls need to be made to
   retrieve some kind of information before running the final command.
 
+  If temporary files or directories are created for commands run with
+  `command_callback` or `command_chain`, then these tempoary files or
+  directories can be managed by ALE, for automatic deletion.
+  See |ale#engine#ManageFile()| and |ale#engine#ManageDirectory| for more
+  information.
+
   Some programs for checking for errors are not capable of receiving input
   from stdin, as is required by ALE. To remedy this, a wrapper script is
   provided named in the variable |g:ale#util#stdin_wrapper|. This variable
diff --git a/test/test_cleanup.vader b/test/test_cleanup.vader
index ec2b38aa..23e5bcf0 100644
--- a/test/test_cleanup.vader
+++ b/test/test_cleanup.vader
@@ -2,8 +2,8 @@ Before:
     let g:buffer = bufnr('%')
 
     let g:ale_buffer_info = {
-    \  g:buffer : {},
-    \  10347: {},
+    \  g:buffer : {'temporary_file_list': [], 'temporary_directory_list': []},
+    \  10347: {'temporary_file_list': [], 'temporary_directory_list': []},
     \}
 
 After:
@@ -12,4 +12,4 @@ After:
 
 Execute('ALE globals should be cleared when the buffer is closed.'):
     :q!
-    AssertEqual {10347: {}}, g:ale_buffer_info
+    AssertEqual {10347: {'temporary_file_list': [], 'temporary_directory_list': []}}, g:ale_buffer_info
diff --git a/test/test_temporary_file_management.vader b/test/test_temporary_file_management.vader
new file mode 100644
index 00000000..17a375e1
--- /dev/null
+++ b/test/test_temporary_file_management.vader
@@ -0,0 +1,83 @@
+Before:
+  let g:command = 'echo test'
+  let g:filename = tempname()
+  let g:directory = tempname()
+  let g:preserved_directory = tempname()
+
+  function! TestCommandCallback(buffer) abort
+    " We are registering a temporary file, so we should delete it.
+    call writefile(['foo'], g:filename)
+    call ale#engine#ManageFile(a:buffer, g:filename)
+
+    " We are registering this directory appropriately, so we should delete
+    " the whole thing.
+    call mkdir(g:directory)
+    call writefile(['foo'], g:directory . '/bar')
+    call ale#engine#ManageDirectory(a:buffer, g:directory)
+
+    " We are registering this directory as temporary file, so we
+    " shouldn't delete it.
+    call mkdir(g:preserved_directory)
+    call writefile(['foo'], g:preserved_directory . '/bar')
+    call ale#engine#ManageFile(a:buffer, g:preserved_directory)
+
+    return g:command
+  endfunction
+
+  function! TestCallback(buffer, output) abort
+    return []
+  endfunction
+
+  call ale#linter#Define('foobar', {
+  \ 'name': 'testlinter',
+  \ 'executable': 'echo',
+  \ 'callback': 'TestCallback',
+  \ 'command_callback': 'TestCommandCallback',
+  \})
+
+After:
+  call delete(g:preserved_directory, 'rf')
+
+  unlet! g:command
+  unlet! g:filename
+  unlet! g:directory
+  unlet! g:preserved_directory
+  delfunction TestCommandCallback
+  delfunction TestCallback
+  call ale#linter#Reset()
+
+Given foobar (Some imaginary filetype):
+  foo
+  bar
+  baz
+
+Execute(ALE should delete managed files/directories appropriately after linting):
+  AssertEqual 'foobar', &filetype
+
+  call ale#Lint()
+  call ale#engine#WaitForJobs(2000)
+
+  Assert !filereadable(g:filename), 'The tempoary file was not deleted'
+  Assert !isdirectory(g:directory), 'The tempoary directory was not deleted'
+  Assert isdirectory(g:preserved_directory), 'The tempoary directory was not kept'
+
+Execute(ALE should delete managed files even if no command is run):
+  AssertEqual 'foobar', &filetype
+
+  let g:command = ''
+
+  call ale#Lint()
+  call ale#engine#WaitForJobs(2000)
+
+  Assert !filereadable(g:filename), 'The tempoary file was not deleted'
+  Assert !isdirectory(g:directory), 'The tempoary directory was not deleted'
+  Assert isdirectory(g:preserved_directory), 'The tempoary directory was not kept'
+
+Execute(ALE should delete managed files when the buffer is removed):
+  call ale#engine#InitBufferInfo(bufnr('%'))
+  call TestCommandCallback(bufnr('%'))
+  call ale#cleanup#Buffer(bufnr('%'))
+
+  Assert !filereadable(g:filename), 'The tempoary file was not deleted'
+  Assert !isdirectory(g:directory), 'The tempoary directory was not deleted'
+  Assert isdirectory(g:preserved_directory), 'The tempoary directory was not kept'