From 80ff84db84ba172bfcdee5e2748924bb2249134b Mon Sep 17 00:00:00 2001
From: w0rp <devw0rp@gmail.com>
Date: Tue, 20 May 2025 16:59:42 +0100
Subject: [PATCH] Skip whitespace warnings from ruff, if so configured

---
 ale_linters/python/ruff.vim          | 33 ++++++++-----
 test/handler/test_ruff_handler.vader | 74 ++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+), 11 deletions(-)

diff --git a/ale_linters/python/ruff.vim b/ale_linters/python/ruff.vim
index 8eb55164..e6fbda2a 100644
--- a/ale_linters/python/ruff.vim
+++ b/ale_linters/python/ruff.vim
@@ -72,20 +72,31 @@ function! ale_linters#python#ruff#Handle(buffer, lines) abort
         try
             let l:item = json_decode(l:line)
         catch
-            let l:item = v:null
+            " If we can't decode a line, skip it.
+            continue
         endtry
 
-        if !empty(l:item)
-            call add(l:output, {
-            \   'lnum': l:item.location.row,
-            \   'col': l:item.location.column,
-            \   'end_lnum': l:item.end_location.row,
-            \   'end_col': l:item.end_location.column - 1,
-            \   'code': l:item.code,
-            \   'text': l:item.message,
-            \   'type': l:item.code =~? '\vE\d+' ? 'E' : 'W',
-            \})
+        if (l:item.code is# 'W291' || l:item.code is# 'W293')
+        \&& !ale#Var(a:buffer, 'warn_about_trailing_whitespace')
+            " Skip warnings for trailing whitespace if the option is off.
+            continue
         endif
+
+        if l:item.code is# 'W391'
+        \&& !ale#Var(a:buffer, 'warn_about_trailing_blank_lines')
+            " Skip warnings for trailing blank lines if the option is off
+            continue
+        endif
+
+        call add(l:output, {
+        \   'lnum': l:item.location.row,
+        \   'col': l:item.location.column,
+        \   'end_lnum': l:item.end_location.row,
+        \   'end_col': l:item.end_location.column - 1,
+        \   'code': l:item.code,
+        \   'text': l:item.message,
+        \   'type': l:item.code =~? '\vE\d+' ? 'E' : 'W',
+        \})
     endfor
 
     return l:output
diff --git a/test/handler/test_ruff_handler.vader b/test/handler/test_ruff_handler.vader
index 82012706..6a834a37 100644
--- a/test/handler/test_ruff_handler.vader
+++ b/test/handler/test_ruff_handler.vader
@@ -1,7 +1,18 @@
 Before:
+  Save g:ale_warn_about_trailing_blank_lines
+  Save g:ale_warn_about_trailing_whitespace
+
+  let g:ale_warn_about_trailing_blank_lines = 1
+  let g:ale_warn_about_trailing_whitespace = 1
+
   runtime ale_linters/python/ruff.vim
 
 After:
+  Restore
+
+  unlet! b:ale_warn_about_trailing_blank_lines
+  unlet! b:ale_warn_about_trailing_whitespace
+
   call ale#linter#Reset()
 
 Execute(We should handle basic output of ruff correctly):
@@ -41,3 +52,66 @@ Execute(We should handle mixed error lines and JSON output from ruff):
   \   'ERROR: oh noes!',
   \   '{"cell":null,"code":"F821","end_location":{"column":8,"row":2},"filename":"/home/eduardo/Code/Python/test.py","fix":null,"location":{"column":1,"row":2},"message":"Undefined name example","noqa_row":2,"url":"https://docs.astral.sh/ruff/rules/undefined-name"}',
   \ ])
+
+Execute(Warnings about trailing whitespace should be reported by default):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 6,
+  \     'col': 1,
+  \     'end_lnum': 6,
+  \     'end_col': 1,
+  \     'code': 'W291',
+  \     'type': 'W',
+  \     'text': 'who cares',
+  \   },
+  \   {
+  \     'lnum': 6,
+  \     'col': 1,
+  \     'end_lnum': 6,
+  \     'end_col': 1,
+  \     'code': 'W293',
+  \     'type': 'W',
+  \     'text': 'who cares',
+  \   },
+  \ ],
+  \ ale_linters#python#ruff#Handle(bufnr(''), [
+  \   '{"cell":null,"code":"W291","end_location":{"column":2,"row":6},"filename":"/test.py","fix":null,"location":{"column":1,"row":6},"message":"who cares","noqa_row":2,"url":""}',
+  \   '{"cell":null,"code":"W293","end_location":{"column":2,"row":6},"filename":"/test.py","fix":null,"location":{"column":1,"row":6},"message":"who cares","noqa_row":2,"url":""}',
+  \ ])
+
+Execute(Disabling trailing whitespace warnings should work):
+  let b:ale_warn_about_trailing_whitespace = 0
+
+  AssertEqual
+  \ [],
+  \ ale_linters#python#ruff#Handle(bufnr(''), [
+  \   '{"cell":null,"code":"W291","end_location":{"column":2,"row":6},"filename":"/test.py","fix":null,"location":{"column":1,"row":6},"message":"who cares","noqa_row":2,"url":""}',
+  \   '{"cell":null,"code":"W293","end_location":{"column":2,"row":6},"filename":"/test.py","fix":null,"location":{"column":1,"row":6},"message":"who cares","noqa_row":2,"url":""}',
+  \ ])
+
+Execute(Warnings about trailing blank lines should be reported by default):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 6,
+  \     'col': 1,
+  \     'end_lnum': 6,
+  \     'end_col': 1,
+  \     'code': 'W391',
+  \     'type': 'W',
+  \     'text': 'blank line at end of file',
+  \   },
+  \ ],
+  \ ale_linters#python#ruff#Handle(bufnr(''), [
+  \   '{"cell":null,"code":"W391","end_location":{"column":2,"row":6},"filename":"/test.py","fix":null,"location":{"column":1,"row":6},"message":"blank line at end of file","noqa_row":2,"url":""}',
+  \ ])
+
+Execute(Disabling trailing blank line warnings should work):
+  let b:ale_warn_about_trailing_blank_lines = 0
+
+  AssertEqual
+  \ [],
+  \ ale_linters#python#ruff#Handle(bufnr(''), [
+  \   '{"cell":null,"code":"W391","end_location":{"column":2,"row":6},"filename":"/test.py","fix":null,"location":{"column":1,"row":6},"message":"blank line at end of file","noqa_row":2,"url":""}',
+  \ ])