Fix 3897 - add poetry to isort (#3898)

Co-authored-by: Horacio Sanson <horacio@allm.inc>

autoload/ale/fixers/isort.vim

@@ -5,6 +5,7 @@ call ale#Set('python_isort_executable', 'isort')
 call ale#Set('python_isort_use_global', get(g:, 'ale_use_global_executables', 0))
 call ale#Set('python_isort_options', '')
 call ale#Set('python_isort_auto_pipenv', 0)
+call ale#Set('python_isort_auto_poetry', 0)
 
 function! ale#fixers#isort#GetExecutable(buffer) abort
     if (ale#Var(a:buffer, 'python_auto_pipenv') || ale#Var(a:buffer, 'python_isort_auto_pipenv'))
@@ -12,24 +13,34 @@ function! ale#fixers#isort#GetExecutable(buffer) abort
         return 'pipenv'
     endif
 
+    if (ale#Var(a:buffer, 'python_auto_poetry') || ale#Var(a:buffer, 'python_isort_auto_poetry'))
+    \ && ale#python#PoetryPresent(a:buffer)
+        return 'poetry'
+    endif
+
     return ale#python#FindExecutable(a:buffer, 'python_isort', ['isort'])
 endfunction
 
 function! ale#fixers#isort#Fix(buffer) abort
-    let l:options = ale#Var(a:buffer, 'python_isort_options')
     let l:executable = ale#fixers#isort#GetExecutable(a:buffer)
-    let l:exec_args = l:executable =~? 'pipenv$'
-    \   ? ' run isort'
-    \   : ''
+    let l:cmd = [ale#Escape(l:executable)]
 
-    if !executable(l:executable) && l:executable isnot# 'pipenv'
-        return 0
+    if l:executable =~? 'pipenv\|poetry$'
+        call extend(l:cmd, ['run', 'isort'])
     endif
 
+    call add(l:cmd, '--filename %s')
+
+    let l:options = ale#Var(a:buffer, 'python_isort_options')
+
+    if !empty(l:options)
+        call add(l:cmd, l:options)
+    endif
+
+    call add(l:cmd, '-')
+
     return {
     \   'cwd': '%s:h',
-    \   'command': ale#Escape(l:executable) . l:exec_args
-    \   . ale#Pad('--filename %s')
-    \   . (!empty(l:options) ? ' ' . l:options : '') . ' -',
+    \   'command': join(l:cmd, ' ')
     \}
 endfunction