#2172 Auto PATH with ale_python_auto_virtualenv

Automatically set `PATH` for some Python linters that seem to need it
when g:ale_python_auto_virtualenv or b:ale_python_auto_virtualenv is
`1`.

10 files changed, 174 insertions, 54 deletions

diff --git a/ale_linters/python/jedils.vim b/ale_linters/python/jedils.vim
index eae5fb07..d3e15bf2 100644
--- a/ale_linters/python/jedils.vim
+++ b/ale_linters/python/jedils.vim
@@ -16,12 +16,16 @@ endfunction
 
 function! ale_linters#python#jedils#GetCommand(buffer) abort
     let l:executable = ale_linters#python#jedils#GetExecutable(a:buffer)
-
     let l:exec_args = l:executable =~? 'pipenv$'
     \   ? ' run jedi-language-server'
     \   : ''
+    let l:env_string = ''
+
+    if ale#Var(a:buffer, 'python_auto_virtualenv')
+        let l:env_string = ale#python#AutoVirtualenvEnvString(a:buffer)
+    endif
 
-    return ale#Escape(l:executable) . l:exec_args
+    return l:env_string . ale#Escape(l:executable) . l:exec_args
 endfunction
 
 call ale#linter#Define('python', {
diff --git a/ale_linters/python/pylsp.vim b/ale_linters/python/pylsp.vim
index a699e4f6..a1c31018 100644
--- a/ale_linters/python/pylsp.vim
+++ b/ale_linters/python/pylsp.vim
@@ -37,12 +37,16 @@ endfunction
 
 function! ale_linters#python#pylsp#GetCommand(buffer) abort
     let l:executable = ale_linters#python#pylsp#GetExecutable(a:buffer)
-
     let l:exec_args = l:executable =~? 'pipenv\|poetry$'
     \   ? ' run pylsp'
     \   : ''
+    let l:env_string = ''
+
+    if ale#Var(a:buffer, 'python_auto_virtualenv')
+        let l:env_string = ale#python#AutoVirtualenvEnvString(a:buffer)
+    endif
 
-    return ale#Escape(l:executable) . l:exec_args . ale#Pad(ale#Var(a:buffer, 'python_pylsp_options'))
+    return l:env_string . ale#Escape(l:executable) . l:exec_args . ale#Pad(ale#Var(a:buffer, 'python_pylsp_options'))
 endfunction
 
 call ale#linter#Define('python', {
diff --git a/ale_linters/python/pyright.vim b/ale_linters/python/pyright.vim
index f16af84c..ccade0c9 100644
--- a/ale_linters/python/pyright.vim
+++ b/ale_linters/python/pyright.vim
@@ -64,12 +64,16 @@ endfunction
 
 function! ale_linters#python#pyright#GetCommand(buffer) abort
     let l:executable = ale_linters#python#pyright#GetExecutable(a:buffer)
-
     let l:exec_args = l:executable =~? 'pipenv\|poetry$'
     \   ? ' run pyright'
     \   : ''
+    let l:env_string = ''
+
+    if ale#Var(a:buffer, 'python_auto_virtualenv')
+        let l:env_string = ale#python#AutoVirtualenvEnvString(a:buffer)
+    endif
 
-    return ale#Escape(l:executable) . l:exec_args . ' --stdio'
+    return l:env_string . ale#Escape(l:executable) . l:exec_args . ' --stdio'
 endfunction
 
 call ale#linter#Define('python', {
diff --git a/autoload/ale/python.vim b/autoload/ale/python.vim
index 7a998414..92e48da8 100644
--- a/autoload/ale/python.vim
+++ b/autoload/ale/python.vim
@@ -1,4 +1,4 @@
-" Author: w0rp <devw0rp@gmail.com>
+" Author: w0rp <dev@w0rp.com>
 " Description: Functions for integrating with Python linters.
 
 call ale#Set('python_auto_pipenv', '0')
@@ -96,6 +96,24 @@ function! ale#python#FindVirtualenv(buffer) abort
     return $VIRTUAL_ENV
 endfunction
 
+" Automatically determine virtualenv environment variables and build
+" a string of them to prefix linter commands with.
+function! ale#python#AutoVirtualenvEnvString(buffer) abort
+    let l:venv_dir = ale#python#FindVirtualenv(a:buffer)
+    let l:sep = has('win32') ? ';' : ':'
+
+    if !empty(l:venv_dir)
+        let l:vars = [
+        \   ['PATH', ale#path#Simplify(l:venv_dir . '/bin') . l:sep . $PATH],
+        \]
+
+        " We don't need a space between var as ale#Env adds one.
+        return join(map(l:vars, 'ale#Env(v:val[0], v:val[1])'), '')
+    endif
+
+    return ''
+endfunction
+
 " Given a buffer number and a command name, find the path to the executable.
 " First search on a virtualenv for Python, if nothing is found, try the global
 " command. Returns an empty string if cannot find the executable
diff --git a/doc/ale-python.txt b/doc/ale-python.txt
index aad64b1d..d7c5cacc 100644
--- a/doc/ale-python.txt
+++ b/doc/ale-python.txt
@@ -20,6 +20,17 @@ g:ale_python_auto_poetry                             *g:ale_python_auto_poetry*
   if true. This is overridden by a manually-set executable.
 
 
+g:ale_python_auto_virtualenv                     *g:ale_python_auto_virtualenv*
+                                                 *b:ale_python_auto_virtualenv*
+  Type: |Number|
+  Default: `0`
+
+  If set to `1`, ALE will automatically set environment variables for commands
+  such as `PATH` to attempt to make the experience of running Python linters
+  via virtualenv easier, without the need for another plugin or some
+  specialised setup.
+
+
 ===============================================================================
 ALE Python Project Root Behavior                              *ale-python-root*
 
@@ -88,24 +99,24 @@ g:ale_python_autoflake_use_global           *g:ale_python_autoflake_use_global*
 ===============================================================================
 autoimport                                              *ale-python-autoimport*
 
-g:ale_python_autoimport_executable             *g:ale_python_autoimport_executable*
-                                             *b:ale_python_autoimport_executable*
+g:ale_python_autoimport_executable         *g:ale_python_autoimport_executable*
+                                           *b:ale_python_autoimport_executable*
   Type: |String|
   Default: `'autoimport'`
 
   See |ale-integrations-local-executables|
 
 
-g:ale_python_autoimport_options                   *g:ale_python_autoimport_options*
-                                                *b:ale_python_autoimport_options*
+g:ale_python_autoimport_options               *g:ale_python_autoimport_options*
+                                              *b:ale_python_autoimport_options*
   Type: |String|
   Default: `''`
 
   This variable can be set to pass extra options to autoimport.
 
 
-g:ale_python_autoimport_use_global             *g:ale_python_autoimport_use_global*
-                                             *b:ale_python_autoimport_use_global*
+g:ale_python_autoimport_use_global         *g:ale_python_autoimport_use_global*
+                                           *b:ale_python_autoimport_use_global*
   Type: |Number|
   Default: `get(g:, 'ale_use_global_executables', 0)`
 
@@ -338,7 +349,7 @@ g:ale_python_flake8_auto_poetry               *g:ale_python_flake8_auto_poetry*
 flakehell                                                *ale-python-flakehell*
 
 g:ale_python_flakehell_change_directory*g:ale_python_flakehell_change_directory*
-                                       *b:ale_python_flakehell_change_directory*
+                                      *b:ale_python_flakehell_change_directory*
   Type: |String|
   Default: `project`
 
@@ -349,8 +360,8 @@ g:ale_python_flakehell_change_directory*g:ale_python_flakehell_change_directory*
   Python is executed from yourself.
 
 
-g:ale_python_flakehell_executable            *g:ale_python_flakehell_executable*
-                                             *b:ale_python_flakehell_executable*
+g:ale_python_flakehell_executable           *g:ale_python_flakehell_executable*
+                                            *b:ale_python_flakehell_executable*
   Type: |String|
   Default: `'flakehell'`
 
@@ -360,8 +371,8 @@ g:ale_python_flakehell_executable            *g:ale_python_flakehell_executable*
   invoke `'python` `-m` `flakehell'`.
 
 
-g:ale_python_flakehell_options                  *g:ale_python_flakehell_options*
-                                                *b:ale_python_flakehell_options*
+g:ale_python_flakehell_options                 *g:ale_python_flakehell_options*
+                                               *b:ale_python_flakehell_options*
   Type: |String|
   Default: `''`
 
@@ -369,8 +380,8 @@ g:ale_python_flakehell_options                  *g:ale_python_flakehell_options*
   lint invocation.
 
 
-g:ale_python_flakehell_use_global            *g:ale_python_flakehell_use_global*
-                                             *b:ale_python_flakehell_use_global*
+g:ale_python_flakehell_use_global           *g:ale_python_flakehell_use_global*
+                                            *b:ale_python_flakehell_use_global*
   Type: |Number|
   Default: `get(g:, 'ale_use_global_executables', 0)`
 
@@ -381,8 +392,8 @@ g:ale_python_flakehell_use_global            *g:ale_python_flakehell_use_global*
   Both variables can be set with `b:` buffer variables instead.
 
 
-g:ale_python_flakehell_auto_pipenv          *g:ale_python_flakehell_auto_pipenv*
-                                            *b:ale_python_flakehell_auto_pipenv*
+g:ale_python_flakehell_auto_pipenv         *g:ale_python_flakehell_auto_pipenv*
+                                           *b:ale_python_flakehell_auto_pipenv*
   Type: |Number|
   Default: `0`
 
@@ -975,13 +986,13 @@ g:ale_python_pylint_use_msg_id                 *g:ale_python_pylint_use_msg_id*
 
 
 ===============================================================================
-pylsp                                                          *ale-python-pylsp*
+pylsp                                                        *ale-python-pylsp*
 
 `pylsp` will be run from a detected project root, per |ale-python-root|.
 
 
-g:ale_python_pylsp_executable                     *g:ale_python_pylsp_executable*
-                                                 *b:ale_python_pylsp_executable*
+g:ale_python_pylsp_executable                   *g:ale_python_pylsp_executable*
+                                                *b:ale_python_pylsp_executable*
   Type: |String|
   Default: `'pylsp'`
 
@@ -991,16 +1002,16 @@ g:ale_python_pylsp_executable                     *g:ale_python_pylsp_executable
   Set this to `'poetry'` to invoke `'poetry` `run` `pyls'`.
 
 
-g:ale_python_pylsp_use_global                     *g:ale_python_pylsp_use_global*
-                                                 *b:ale_python_pylsp_use_global*
+g:ale_python_pylsp_use_global                   *g:ale_python_pylsp_use_global*
+                                                *b:ale_python_pylsp_use_global*
   Type: |Number|
   Default: `get(g:, 'ale_use_global_executables', 0)`
 
   See |ale-integrations-local-executables|
 
 
-g:ale_python_pylsp_auto_pipenv                   *g:ale_python_pylsp_auto_pipenv*
-                                                *b:ale_python_pylsp_auto_pipenv*
+g:ale_python_pylsp_auto_pipenv                 *g:ale_python_pylsp_auto_pipenv*
+                                               *b:ale_python_pylsp_auto_pipenv*
   Type: |Number|
   Default: `0`
 
@@ -1008,8 +1019,8 @@ g:ale_python_pylsp_auto_pipenv                   *g:ale_python_pylsp_auto_pipenv
   if true. This is overridden by a manually-set executable.
 
 
-g:ale_python_pylsp_auto_poetry                   *g:ale_python_pylsp_auto_poetry*
-                                                *b:ale_python_pylsp_auto_poetry*
+g:ale_python_pylsp_auto_poetry                 *g:ale_python_pylsp_auto_poetry*
+                                               *b:ale_python_pylsp_auto_poetry*
   Type: |Number|
   Default: `0`
 
@@ -1017,8 +1028,8 @@ g:ale_python_pylsp_auto_poetry                   *g:ale_python_pylsp_auto_poetry
   if true. This is overridden by a manually-set executable.
 
 
-g:ale_python_pylsp_config                             *g:ale_python_pylsp_config*
-                                                     *b:ale_python_pylsp_config*
+g:ale_python_pylsp_config                           *g:ale_python_pylsp_config*
+                                                    *b:ale_python_pylsp_config*
   Type: |Dictionary|
   Default: `{}`
 
@@ -1035,8 +1046,8 @@ g:ale_python_pylsp_config                             *g:ale_python_pylsp_config
       \ }
 <
 
-g:ale_python_pylsp_options                           *g:ale_python_pylsp_options*
-                                                    *b:ale_python_pylsp_options*
+g:ale_python_pylsp_options                         *g:ale_python_pylsp_options*
+                                                   *b:ale_python_pylsp_options*
   Type: |String|
   Default: `''`
 
@@ -1158,10 +1169,10 @@ g:ale_python_pyright_config                       *g:ale_python_pyright_config*
 <
 
 ===============================================================================
-refurb                                                        *ale-python-refurb*
+refurb                                                      *ale-python-refurb*
 
-g:ale_python_refurb_change_directory       *g:ale_python_refurb_change_directory*
-                                           *b:ale_python_refurb_change_directory*
+g:ale_python_refurb_change_directory     *g:ale_python_refurb_change_directory*
+                                         *b:ale_python_refurb_change_directory*
   Type: |Number|
   Default: `1`
 
@@ -1170,8 +1181,8 @@ g:ale_python_refurb_change_directory       *g:ale_python_refurb_change_directory
   `refurb` will be run from the buffer's directory.
 
 
-g:ale_python_refurb_executable                   *g:ale_python_refurb_executable*
-                                                 *b:ale_python_refurb_executable*
+g:ale_python_refurb_executable                 *g:ale_python_refurb_executable*
+                                               *b:ale_python_refurb_executable*
   Type: |String|
   Default: `'refurb'`
 
@@ -1181,8 +1192,8 @@ g:ale_python_refurb_executable                   *g:ale_python_refurb_executable
   Set this to `'poetry'` to invoke `'poetry` `run` `refurb'`.
 
 
-g:ale_python_refurb_options                         *g:ale_python_refurb_options*
-                                                    *b:ale_python_refurb_options*
+g:ale_python_refurb_options                       *g:ale_python_refurb_options*
+                                                  *b:ale_python_refurb_options*
   Type: |String|
   Default: `''`
 
@@ -1192,16 +1203,16 @@ g:ale_python_refurb_options                         *g:ale_python_refurb_options
   For example, to select/enable and/or disable some error codes,
   you may want to set >
   let g:ale_python_refurb_options = '--ignore 100'
-g:ale_python_refurb_use_global                   *g:ale_python_refurb_use_global*
-                                                 *b:ale_python_refurb_use_global*
+g:ale_python_refurb_use_global                 *g:ale_python_refurb_use_global*
+                                               *b:ale_python_refurb_use_global*
   Type: |Number|
   Default: `get(g:, 'ale_use_global_executables', 0)`
 
   See |ale-integrations-local-executables|
 
 
-g:ale_python_refurb_auto_pipenv                 *g:ale_python_refurb_auto_pipenv*
-                                                *b:ale_python_refurb_auto_pipenv*
+g:ale_python_refurb_auto_pipenv               *g:ale_python_refurb_auto_pipenv*
+                                              *b:ale_python_refurb_auto_pipenv*
   Type: |Number|
   Default: `0`
 
@@ -1209,8 +1220,8 @@ g:ale_python_refurb_auto_pipenv                 *g:ale_python_refurb_auto_pipenv
   if true. This is overridden by a manually-set executable.
 
 
-g:ale_python_refurb_auto_poetry                 *g:ale_python_refurb_auto_poetry*
-                                                *b:ale_python_refurb_auto_poetry*
+g:ale_python_refurb_auto_poetry               *g:ale_python_refurb_auto_poetry*
+                                              *b:ale_python_refurb_auto_poetry*
   Type: |Number|
   Default: `0`
 
@@ -1335,8 +1346,8 @@ g:ale_python_unimport_auto_poetry           *g:ale_python_unimport_auto_poetry*
   if true. This is overridden by a manually-set executable.
 
 
-g:ale_python_unimport_executable              *g:ale_python_unimport_executable*
-                                              *b:ale_python_unimport_executable*
+g:ale_python_unimport_executable             *g:ale_python_unimport_executable*
+                                             *b:ale_python_unimport_executable*
   Type: |String|
   Default: `'unimport'`
 
@@ -1346,8 +1357,8 @@ g:ale_python_unimport_executable              *g:ale_python_unimport_executable*
   Set this to `'poetry'` to invoke `'poetry` `run` `unimport'`.
 
 
-g:ale_python_unimport_options                    *g:ale_python_unimport_options*
-                                                 *b:ale_python_unimport_options*
+g:ale_python_unimport_options                   *g:ale_python_unimport_options*
+                                                *b:ale_python_unimport_options*
   Type: |String|
   Default: `''`
 
@@ -1355,8 +1366,8 @@ g:ale_python_unimport_options                    *g:ale_python_unimport_options*
   invocation.
 
 
-g:ale_python_unimport_use_global              *g:ale_python_unimport_use_global*
-                                              *b:ale_python_unimport_use_global*
+g:ale_python_unimport_use_global             *g:ale_python_unimport_use_global*
+                                             *b:ale_python_unimport_use_global*
   Type: |Number|
   Default: `get(g:, 'ale_use_global_executables', 0)`
 
diff --git a/plugin/ale.vim b/plugin/ale.vim
index b9786bb0..f9b6cab8 100644
--- a/plugin/ale.vim
+++ b/plugin/ale.vim
@@ -178,6 +178,10 @@ let g:ale_python_auto_pipenv = get(g:, 'ale_python_auto_pipenv', 0)
 " Enable automatic detection of poetry for Python linters.
 let g:ale_python_auto_poetry = get(g:, 'ale_python_auto_poetry', 0)
 
+" Enable automatic adjustment of environment variables for Python linters.
+" The variables are set based on ALE's virtualenv detection.
+let g:ale_python_auto_virtualenv = get(g:, 'ale_python_auto_virtualenv', 0)
+
 " This variable can be overridden to set the GO111MODULE environment variable.
 let g:ale_go_go111module = get(g:, 'ale_go_go111module', '')
 
diff --git a/test/linter/test_jedils.vader b/test/linter/test_jedils.vader
new file mode 100644
index 00000000..0c2781bd
--- /dev/null
+++ b/test/linter/test_jedils.vader
@@ -0,0 +1,47 @@
+Before:
+  call ale#assert#SetUpLinterTest('python', 'jedils')
+  Save b:ale_python_auto_virtualenv
+
+  let b:bin_dir = has('win32') ? 'Scripts' : 'bin'
+
+After:
+  unlet! b:bin_dir
+  unlet! b:venv_bin
+  unlet! b:sep
+  unlet! b:executable
+
+  call ale#assert#TearDownLinterTest()
+
+Execute(The jedi-language-server command callback should return default string):
+  call ale#test#SetFilename('./foo.py')
+
+  AssertLinter 'jedi-language-server', ale#Escape('jedi-language-server')
+
+Execute(The jedi-language-server executable should be configurable):
+  let g:ale_python_jedils_executable = '~/.local/bin/jedi-language-server'
+
+  AssertLinter '~/.local/bin/jedi-language-server' , ale#Escape('~/.local/bin/jedi-language-server')
+
+Execute(virtualenv vars should be used when ale_python_auto_virtualenv = 1):
+  let b:ale_python_auto_virtualenv = 1
+  call ale#test#SetFilename('../test-files/python/with_virtualenv/subdir/foo/bar.py')
+
+  let b:venv_bin = ale#path#Simplify(g:dir . '/../test-files/python/with_virtualenv/env/' . b:bin_dir)
+  let b:sep = has('win32') ? ';' : ':'
+  let b:executable = ale#path#Simplify(b:venv_bin . '/jedi-language-server')
+
+  AssertLinter b:executable, ale#Env('PATH', b:venv_bin . b:sep . $PATH)
+  \   . ale#Escape(b:executable)
+
+Execute(You should be able to override the jedi-language-server virtualenv lookup):
+  call ale#test#SetFilename('../test-files/python/with_virtualenv/subdir/foo/bar.py')
+
+  let g:ale_python_jedils_use_global = 1
+
+  AssertLinter 'jedi-language-server', ale#Escape('jedi-language-server')
+
+Execute(Setting executable to 'pipenv' appends 'run jedi-language-server'):
+  let g:ale_python_jedils_executable = 'path/to/pipenv'
+  call ale#test#SetFilename('../test-files/dummy')
+
+  AssertLinter 'path/to/pipenv', ale#Escape('path/to/pipenv') . ' run jedi-language-server'
diff --git a/test/linter/test_pylsp.vader b/test/linter/test_pylsp.vader
index 34cc30c6..d1490978 100644
--- a/test/linter/test_pylsp.vader
+++ b/test/linter/test_pylsp.vader
@@ -1,10 +1,13 @@
 Before:
   call ale#assert#SetUpLinterTest('python', 'pylsp')
+  Save b:ale_python_auto_virtualenv
 
   let b:bin_dir = has('win32') ? 'Scripts' : 'bin'
 
 After:
   unlet! b:bin_dir
+  unlet! b:venv_bin
+  unlet! b:sep
   unlet! b:executable
 
   call ale#assert#TearDownLinterTest()
@@ -40,6 +43,17 @@ Execute(The pylsp executable should be run from the virtualenv path):
   AssertEqual ale#Escape(b:executable),
   \ ale_linters#python#pylsp#GetCommand(bufnr(''))
 
+Execute(virtualenv vars should be used when ale_python_auto_virtualenv = 1):
+  let b:ale_python_auto_virtualenv = 1
+  call ale#test#SetFilename('../test-files/python/with_virtualenv/subdir/foo/bar.py')
+
+  let b:venv_bin = ale#path#Simplify(g:dir . '/../test-files/python/with_virtualenv/env/' . b:bin_dir)
+  let b:sep = has('win32') ? ';' : ':'
+  let b:executable = ale#path#Simplify(b:venv_bin . '/pylsp')
+
+  AssertLinter b:executable, ale#Env('PATH', b:venv_bin . b:sep . $PATH)
+  \   . ale#Escape(b:executable)
+
 Execute(You should be able to override the pylsp virtualenv lookup):
   call ale#test#SetFilename('../test-files/python/with_virtualenv/subdir/foo/bar.py')
 
diff --git a/test/linter/test_pyright.vader b/test/linter/test_pyright.vader
index 303efa24..c81ab4b4 100644
--- a/test/linter/test_pyright.vader
+++ b/test/linter/test_pyright.vader
@@ -1,10 +1,13 @@
 Before:
   call ale#assert#SetUpLinterTest('python', 'pyright')
+  Save b:ale_python_auto_virtualenv
 
   let b:bin_dir = has('win32') ? 'Scripts' : 'bin'
 
 After:
   unlet! b:bin_dir
+  unlet! b:venv_bin
+  unlet! b:sep
   unlet! b:executable
 
   call ale#assert#TearDownLinterTest()
@@ -132,6 +135,17 @@ Execute(The pyright callbacks should detect virtualenv directories):
 
   AssertLinter b:executable, ale#Escape(b:executable) . ' --stdio'
 
+Execute(virtualenv vars should be used when ale_python_auto_virtualenv = 1):
+  let b:ale_python_auto_virtualenv = 1
+  call ale#test#SetFilename('../test-files/python/with_virtualenv/subdir/foo/bar.py')
+
+  let b:venv_bin = ale#path#Simplify(g:dir . '/../test-files/python/with_virtualenv/env/' . b:bin_dir)
+  let b:sep = has('win32') ? ';' : ':'
+  let b:executable = ale#path#Simplify(b:venv_bin . '/pyright-langserver')
+
+  AssertLinter b:executable, ale#Env('PATH', b:venv_bin . b:sep . $PATH)
+  \   . ale#Escape(b:executable) . ' --stdio'
+
 Execute(Setting executable to 'pipenv' should append 'run pyright'):
   call ale#test#SetFilename('../test-files')
 
diff --git a/test/test-files/python/with_virtualenv/env/bin/jedi-language-server b/test/test-files/python/with_virtualenv/env/bin/jedi-language-server
new file mode 100755
index 00000000..e69de29b
--- /dev/null
+++ b/test/test-files/python/with_virtualenv/env/bin/jedi-language-server