From 6bfcb9cdffb86bf1a3e6d26cd1964858ff4bc3dd Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Wed, 8 Apr 2020 17:59:17 -0500
Subject: [PATCH 01/12] linters/xo: consolidate xo linters

---
 ale_linters/javascript/xo.vim                 | 23 ++-------------
 ale_linters/typescript/xo.vim                 | 23 ++-------------
 autoload/ale/handlers/xo.vim                  | 28 +++++++++++++++++++
 .../test_xo_command_callback.vader            | 10 ++++---
 .../test_xots_command_callback.vader          | 22 +++++++++++++++
 5 files changed, 62 insertions(+), 44 deletions(-)
 create mode 100644 autoload/ale/handlers/xo.vim
 create mode 100644 test/command_callback/test_xots_command_callback.vader

diff --git a/ale_linters/javascript/xo.vim b/ale_linters/javascript/xo.vim
index e24f4a82..5b206df8 100644
--- a/ale_linters/javascript/xo.vim
+++ b/ale_linters/javascript/xo.vim
@@ -1,26 +1,9 @@
 " Author: Daniel Lupu <lupu.daniel.f@gmail.com>
 " Description: xo for JavaScript files
 
-call ale#Set('javascript_xo_executable', 'xo')
-call ale#Set('javascript_xo_use_global', get(g:, 'ale_use_global_executables', 0))
-call ale#Set('javascript_xo_options', '')
-
-function! ale_linters#javascript#xo#GetExecutable(buffer) abort
-    return ale#node#FindExecutable(a:buffer, 'javascript_xo', [
-    \   'node_modules/.bin/xo',
-    \])
-endfunction
-
-function! ale_linters#javascript#xo#GetCommand(buffer) abort
-    return ale#Escape(ale_linters#javascript#xo#GetExecutable(a:buffer))
-    \   . ' ' . ale#Var(a:buffer, 'javascript_xo_options')
-    \   . ' --reporter json --stdin --stdin-filename %s'
-endfunction
-
-" xo uses eslint and the output format is the same
 call ale#linter#Define('javascript', {
 \   'name': 'xo',
-\   'executable': function('ale_linters#javascript#xo#GetExecutable'),
-\   'command': function('ale_linters#javascript#xo#GetCommand'),
-\   'callback': 'ale#handlers#eslint#HandleJSON',
+\   'executable': {b -> ale#handlers#xo#GetExecutable(b, 'javascript')},
+\   'command': {b -> ale#handlers#xo#GetLintCommand(b, 'javascript')},
+\   'callback': 'ale#handlers#xo#HandleJSON',
 \})
diff --git a/ale_linters/typescript/xo.vim b/ale_linters/typescript/xo.vim
index 0a3a717b..13ae0cf7 100644
--- a/ale_linters/typescript/xo.vim
+++ b/ale_linters/typescript/xo.vim
@@ -1,23 +1,6 @@
-call ale#Set('typescript_xo_executable', 'xo')
-call ale#Set('typescript_xo_use_global', get(g:, 'ale_use_global_executables', 0))
-call ale#Set('typescript_xo_options', '')
-
-function! ale_linters#typescript#xo#GetExecutable(buffer) abort
-    return ale#node#FindExecutable(a:buffer, 'typescript_xo', [
-    \   'node_modules/.bin/xo',
-    \])
-endfunction
-
-function! ale_linters#typescript#xo#GetCommand(buffer) abort
-    return ale#Escape(ale_linters#typescript#xo#GetExecutable(a:buffer))
-    \   . ale#Pad(ale#Var(a:buffer, 'typescript_xo_options'))
-    \   . ' --reporter json --stdin --stdin-filename %s'
-endfunction
-
-" xo uses eslint and the output format is the same
 call ale#linter#Define('typescript', {
 \   'name': 'xo',
-\   'executable': function('ale_linters#typescript#xo#GetExecutable'),
-\   'command': function('ale_linters#typescript#xo#GetCommand'),
-\   'callback': 'ale#handlers#eslint#HandleJSON',
+\   'executable': {b -> ale#handlers#xo#GetExecutable(b, 'typescript')},
+\   'command': {b -> ale#handlers#xo#GetLintCommand(b, 'typescript')},
+\   'callback': 'ale#handlers#xo#HandleJSON',
 \})
diff --git a/autoload/ale/handlers/xo.vim b/autoload/ale/handlers/xo.vim
new file mode 100644
index 00000000..38dcf5d5
--- /dev/null
+++ b/autoload/ale/handlers/xo.vim
@@ -0,0 +1,28 @@
+call ale#Set('javascript_xo_executable', 'xo')
+call ale#Set('javascript_xo_use_global', get(g:, 'ale_use_global_executables', 0))
+call ale#Set('javascript_xo_options', '')
+
+call ale#Set('typescript_xo_executable', 'xo')
+call ale#Set('typescript_xo_use_global', get(g:, 'ale_use_global_executables', 0))
+call ale#Set('typescript_xo_options', '')
+
+function! ale#handlers#xo#GetExecutable(buffer, type) abort
+    return ale#node#FindExecutable(a:buffer, a:type . '_xo', [
+    \   'node_modules/.bin/xo',
+    \])
+endfunction
+
+function! ale#handlers#xo#GetLintCommand(buffer, type) abort
+    return ale#Escape(ale#handlers#xo#GetExecutable(a:buffer, a:type))
+    \   . ale#Pad(ale#handlers#xo#GetOptions(a:buffer, a:type))
+    \   . ' --reporter json --stdin --stdin-filename %s'
+endfunction
+
+function! ale#handlers#xo#GetOptions(buffer, type) abort
+    return ale#Var(a:buffer, a:type . '_xo_options')
+endfunction
+
+" xo uses eslint and the output format is the same
+function! ale#handlers#xo#HandleJSON(buffer, lines) abort
+    return ale#handlers#eslint#HandleJSON(a:buffer, a:lines)
+endfunction
diff --git a/test/command_callback/test_xo_command_callback.vader b/test/command_callback/test_xo_command_callback.vader
index 65cb4f8a..7a38b2b1 100644
--- a/test/command_callback/test_xo_command_callback.vader
+++ b/test/command_callback/test_xo_command_callback.vader
@@ -1,8 +1,10 @@
 Before:
-  call ale#assert#SetUpLinterTest('typescript', 'xo')
-  call ale#test#SetFilename('testfile.ts')
+  call ale#assert#SetUpLinterTest('javascript', 'xo')
+  call ale#test#SetFilename('testfile.js')
   unlet! b:executable
 
+  runtime autoload/ale/handlers/xo.vim
+
 After:
   call ale#assert#TearDownLinterTest()
 
@@ -10,11 +12,11 @@ Execute(The XO executable should be called):
   AssertLinter 'xo', ale#Escape('xo') . ' --reporter json --stdin --stdin-filename %s'
 
 Execute(The XO executable should be configurable):
-  let b:ale_typescript_xo_executable = 'foobar'
+  let b:ale_javascript_xo_executable = 'foobar'
 
   AssertLinter 'foobar', ale#Escape('foobar') . ' --reporter json --stdin --stdin-filename %s'
 
 Execute(The XO options should be configurable):
-  let b:ale_typescript_xo_options = '--wat'
+  let b:ale_javascript_xo_options = '--wat'
 
   AssertLinter 'xo', ale#Escape('xo') . ' --wat --reporter json --stdin --stdin-filename %s'
diff --git a/test/command_callback/test_xots_command_callback.vader b/test/command_callback/test_xots_command_callback.vader
new file mode 100644
index 00000000..c614ad59
--- /dev/null
+++ b/test/command_callback/test_xots_command_callback.vader
@@ -0,0 +1,22 @@
+Before:
+  call ale#assert#SetUpLinterTest('typescript', 'xo')
+  call ale#test#SetFilename('testfile.ts')
+  unlet! b:executable
+
+  runtime autoload/ale/handlers/xo.vim
+
+After:
+  call ale#assert#TearDownLinterTest()
+
+Execute(The XO executable should be called):
+  AssertLinter 'xo', ale#Escape('xo') . ' --reporter json --stdin --stdin-filename %s'
+
+Execute(The XO executable should be configurable):
+  let b:ale_typescript_xo_executable = 'foobar'
+
+  AssertLinter 'foobar', ale#Escape('foobar') . ' --reporter json --stdin --stdin-filename %s'
+
+Execute(The XO options should be configurable):
+  let b:ale_typescript_xo_options = '--wat'
+
+  AssertLinter 'xo', ale#Escape('xo') . ' --wat --reporter json --stdin --stdin-filename %s'

From 4a6136c27ec2430a1ef5481e0ca10dee03ba178f Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Wed, 8 Apr 2020 18:20:10 -0500
Subject: [PATCH 02/12] fixers/xo: add tests

---
 autoload/ale/fixers/xo.vim                    |  4 ++-
 .../react-app/node_modules/xo/cli.js          |  0
 test/fixers/test_xo_fixer_callback.vader      | 29 +++++++++++++++++++
 3 files changed, 32 insertions(+), 1 deletion(-)
 create mode 100644 test/eslint-test-files/react-app/node_modules/xo/cli.js
 create mode 100644 test/fixers/test_xo_fixer_callback.vader

diff --git a/autoload/ale/fixers/xo.vim b/autoload/ale/fixers/xo.vim
index 882350be..69d23ea3 100644
--- a/autoload/ale/fixers/xo.vim
+++ b/autoload/ale/fixers/xo.vim
@@ -14,10 +14,12 @@ endfunction
 
 function! ale#fixers#xo#Fix(buffer) abort
     let l:executable = ale#fixers#xo#GetExecutable(a:buffer)
+    let l:options = ale#Var(a:buffer, 'javascript_xo_options')
 
     return {
     \   'command': ale#node#Executable(a:buffer, l:executable)
-    \       . ' --fix %t',
+    \       . ' --fix %t'
+    \       . ale#Pad(l:options),
     \   'read_temporary_file': 1,
     \}
 endfunction
diff --git a/test/eslint-test-files/react-app/node_modules/xo/cli.js b/test/eslint-test-files/react-app/node_modules/xo/cli.js
new file mode 100644
index 00000000..e69de29b
diff --git a/test/fixers/test_xo_fixer_callback.vader b/test/fixers/test_xo_fixer_callback.vader
new file mode 100644
index 00000000..8bccd05e
--- /dev/null
+++ b/test/fixers/test_xo_fixer_callback.vader
@@ -0,0 +1,29 @@
+Before:
+  call ale#assert#SetUpFixerTest('javascript', 'xo')
+
+After:
+  call ale#assert#TearDownFixerTest()
+
+Execute(The xo callback should return the correct default values):
+  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.js')
+
+  AssertFixer
+  \ {
+  \   'read_temporary_file': 1,
+  \   'command': (has('win32') ? 'node.exe ' : '')
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ' --fix %t',
+  \ }
+
+Execute(The xo callback should include custom xo options):
+  let g:ale_javascript_xo_options = '--space'
+  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.js')
+
+  AssertFixer
+  \ {
+  \   'read_temporary_file': 1,
+  \   'command': (has('win32') ? 'node.exe ' : '')
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ' --fix %t'
+  \     . ' --space',
+  \ }

From 289f808ccd3098cb19bc3bbbb274524a4fb85ff7 Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Wed, 8 Apr 2020 18:38:47 -0500
Subject: [PATCH 03/12] fixers/xo: refactor to handlers

---
 autoload/ale/fixers/xo.vim               | 15 ++-------------
 autoload/ale/handlers/xo.vim             |  1 +
 test/fixers/test_xo_fixer_callback.vader |  1 +
 3 files changed, 4 insertions(+), 13 deletions(-)

diff --git a/autoload/ale/fixers/xo.vim b/autoload/ale/fixers/xo.vim
index 69d23ea3..06e58508 100644
--- a/autoload/ale/fixers/xo.vim
+++ b/autoload/ale/fixers/xo.vim
@@ -1,20 +1,9 @@
 " Author: Albert Marquez - https://github.com/a-marquez
 " Description: Fixing files with XO.
 
-call ale#Set('javascript_xo_executable', 'xo')
-call ale#Set('javascript_xo_use_global', get(g:, 'ale_use_global_executables', 0))
-call ale#Set('javascript_xo_options', '')
-
-function! ale#fixers#xo#GetExecutable(buffer) abort
-    return ale#node#FindExecutable(a:buffer, 'javascript_xo', [
-    \   'node_modules/xo/cli.js',
-    \   'node_modules/.bin/xo',
-    \])
-endfunction
-
 function! ale#fixers#xo#Fix(buffer) abort
-    let l:executable = ale#fixers#xo#GetExecutable(a:buffer)
-    let l:options = ale#Var(a:buffer, 'javascript_xo_options')
+    let l:executable = ale#handlers#xo#GetExecutable(a:buffer, 'javascript')
+    let l:options = ale#handlers#xo#GetOptions(a:buffer, 'javascript')
 
     return {
     \   'command': ale#node#Executable(a:buffer, l:executable)
diff --git a/autoload/ale/handlers/xo.vim b/autoload/ale/handlers/xo.vim
index 38dcf5d5..3f7c72cb 100644
--- a/autoload/ale/handlers/xo.vim
+++ b/autoload/ale/handlers/xo.vim
@@ -8,6 +8,7 @@ call ale#Set('typescript_xo_options', '')
 
 function! ale#handlers#xo#GetExecutable(buffer, type) abort
     return ale#node#FindExecutable(a:buffer, a:type . '_xo', [
+    \   'node_modules/xo/cli.js',
     \   'node_modules/.bin/xo',
     \])
 endfunction
diff --git a/test/fixers/test_xo_fixer_callback.vader b/test/fixers/test_xo_fixer_callback.vader
index 8bccd05e..0bb3108a 100644
--- a/test/fixers/test_xo_fixer_callback.vader
+++ b/test/fixers/test_xo_fixer_callback.vader
@@ -1,5 +1,6 @@
 Before:
   call ale#assert#SetUpFixerTest('javascript', 'xo')
+  runtime autoload/ale/handlers/xo.vim
 
 After:
   call ale#assert#TearDownFixerTest()

From e75ac9f4975be35e4f33b955f473ba5e336c9ca0 Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Wed, 8 Apr 2020 18:52:53 -0500
Subject: [PATCH 04/12] fixers/xo: support typescript options

---
 autoload/ale/fixers/xo.vim                    | 13 ++++++--
 .../react-app/subdir/testfile.ts              |  0
 test/fixers/test_xo_fixer_callback.vader      |  1 +
 test/fixers/test_xots_fixer_callback.vader    | 31 +++++++++++++++++++
 4 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 test/eslint-test-files/react-app/subdir/testfile.ts
 create mode 100644 test/fixers/test_xots_fixer_callback.vader

diff --git a/autoload/ale/fixers/xo.vim b/autoload/ale/fixers/xo.vim
index 06e58508..6c2901db 100644
--- a/autoload/ale/fixers/xo.vim
+++ b/autoload/ale/fixers/xo.vim
@@ -2,8 +2,17 @@
 " Description: Fixing files with XO.
 
 function! ale#fixers#xo#Fix(buffer) abort
-    let l:executable = ale#handlers#xo#GetExecutable(a:buffer, 'javascript')
-    let l:options = ale#handlers#xo#GetOptions(a:buffer, 'javascript')
+    let l:filetype = getbufvar(a:buffer, '&filetype')
+    let l:type = ''
+
+    if l:filetype =~# 'javascript'
+        let l:type = 'javascript'
+    elseif l:filetype =~# 'typescript'
+        let l:type = 'typescript'
+    endif
+
+    let l:executable = ale#handlers#xo#GetExecutable(a:buffer, l:type)
+    let l:options = ale#handlers#xo#GetOptions(a:buffer, l:type)
 
     return {
     \   'command': ale#node#Executable(a:buffer, l:executable)
diff --git a/test/eslint-test-files/react-app/subdir/testfile.ts b/test/eslint-test-files/react-app/subdir/testfile.ts
new file mode 100644
index 00000000..e69de29b
diff --git a/test/fixers/test_xo_fixer_callback.vader b/test/fixers/test_xo_fixer_callback.vader
index 0bb3108a..d36fe74c 100644
--- a/test/fixers/test_xo_fixer_callback.vader
+++ b/test/fixers/test_xo_fixer_callback.vader
@@ -1,6 +1,7 @@
 Before:
   call ale#assert#SetUpFixerTest('javascript', 'xo')
   runtime autoload/ale/handlers/xo.vim
+  set filetype=javascript
 
 After:
   call ale#assert#TearDownFixerTest()
diff --git a/test/fixers/test_xots_fixer_callback.vader b/test/fixers/test_xots_fixer_callback.vader
new file mode 100644
index 00000000..1ef6a6dd
--- /dev/null
+++ b/test/fixers/test_xots_fixer_callback.vader
@@ -0,0 +1,31 @@
+Before:
+  call ale#assert#SetUpFixerTest('typescript', 'xo')
+  runtime autoload/ale/handlers/xo.vim
+  set filetype=typescript
+
+After:
+  call ale#assert#TearDownFixerTest()
+
+Execute(The xo callback should return the correct default values):
+  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.ts')
+
+  AssertFixer
+  \ {
+  \   'read_temporary_file': 1,
+  \   'command': (has('win32') ? 'node.exe ' : '')
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ' --fix %t',
+  \ }
+
+Execute(The xo callback should include custom xo options):
+  let g:ale_typescript_xo_options = '--space'
+  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.ts')
+
+  AssertFixer
+  \ {
+  \   'read_temporary_file': 1,
+  \   'command': (has('win32') ? 'node.exe ' : '')
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ' --fix %t'
+  \     . ' --space',
+  \ }

From 8ffde14039bdc0c12d1edf961461245eb15858e9 Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Wed, 8 Apr 2020 22:59:54 -0500
Subject: [PATCH 05/12] fixers/xo: support stdin relative to the fixed file

---
 autoload/ale/fixers/xo.vim                 | 29 ++++++++++++++++++++--
 autoload/ale/handlers/xo.vim               |  6 +++++
 test/fixers/test_xo_fixer_callback.vader   | 15 +++++++++++
 test/fixers/test_xots_fixer_callback.vader | 15 +++++++++++
 4 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/autoload/ale/fixers/xo.vim b/autoload/ale/fixers/xo.vim
index 6c2901db..2c8ab114 100644
--- a/autoload/ale/fixers/xo.vim
+++ b/autoload/ale/fixers/xo.vim
@@ -14,10 +14,35 @@ function! ale#fixers#xo#Fix(buffer) abort
     let l:executable = ale#handlers#xo#GetExecutable(a:buffer, l:type)
     let l:options = ale#handlers#xo#GetOptions(a:buffer, l:type)
 
+    return ale#semver#RunWithVersionCheck(
+    \   a:buffer,
+    \   l:executable,
+    \   '%e --version',
+    \   {b, v -> ale#fixers#xo#ApplyFixForVersion(b, v, l:executable, l:options)}
+    \)
+endfunction
+
+function! ale#fixers#xo#ApplyFixForVersion(buffer, version, executable, options) abort
+    let l:executable = ale#node#Executable(a:buffer, a:executable)
+    let l:options = ale#Pad(a:options)
+
+    " 0.30.0 is the first version with a working --stdin --fix
+    if ale#semver#GTE(a:version, [0, 30, 0])
+        let l:project_root = ale#handlers#xo#GetProjectRoot(a:buffer)
+
+        return {
+        \   'command': ale#path#CdString(l:project_root)
+        \       . l:executable
+        \       . ' --stdin --stdin-filename %s'
+        \       . ' --fix'
+        \       . l:options,
+        \}
+    endif
+
     return {
-    \   'command': ale#node#Executable(a:buffer, l:executable)
+    \   'command': l:executable
     \       . ' --fix %t'
-    \       . ale#Pad(l:options),
+    \       . l:options,
     \   'read_temporary_file': 1,
     \}
 endfunction
diff --git a/autoload/ale/handlers/xo.vim b/autoload/ale/handlers/xo.vim
index 3f7c72cb..0bea74e4 100644
--- a/autoload/ale/handlers/xo.vim
+++ b/autoload/ale/handlers/xo.vim
@@ -27,3 +27,9 @@ endfunction
 function! ale#handlers#xo#HandleJSON(buffer, lines) abort
     return ale#handlers#eslint#HandleJSON(a:buffer, a:lines)
 endfunction
+
+function! ale#handlers#xo#GetProjectRoot(buffer) abort
+    let l:package_path = ale#path#FindNearestFile(a:buffer, 'package.json')
+
+    return empty(l:package_path) ? '' : fnamemodify(l:package_path, ':p:h')
+endfunction
diff --git a/test/fixers/test_xo_fixer_callback.vader b/test/fixers/test_xo_fixer_callback.vader
index d36fe74c..ffbecb6c 100644
--- a/test/fixers/test_xo_fixer_callback.vader
+++ b/test/fixers/test_xo_fixer_callback.vader
@@ -29,3 +29,18 @@ Execute(The xo callback should include custom xo options):
   \     . ' --fix %t'
   \     . ' --space',
   \ }
+
+Execute(--stdin should be used when xo is new enough):
+  let g:ale_javascript_xo_options = '--space'
+  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.js')
+
+  GivenCommandOutput ['0.30.0']
+  AssertFixer
+  \ {
+  \   'command': ale#path#CdString(ale#path#Simplify(g:dir . '/../eslint-test-files'))
+  \     . (has('win32') ? 'node.exe ' : '')
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ' --stdin --stdin-filename %s'
+  \     . ' --fix'
+  \     . ' --space',
+  \ }
diff --git a/test/fixers/test_xots_fixer_callback.vader b/test/fixers/test_xots_fixer_callback.vader
index 1ef6a6dd..a26ec03c 100644
--- a/test/fixers/test_xots_fixer_callback.vader
+++ b/test/fixers/test_xots_fixer_callback.vader
@@ -29,3 +29,18 @@ Execute(The xo callback should include custom xo options):
   \     . ' --fix %t'
   \     . ' --space',
   \ }
+
+Execute(--stdin should be used when xo is new enough):
+  let g:ale_typescript_xo_options = '--space'
+  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.ts')
+
+  GivenCommandOutput ['0.30.0']
+  AssertFixer
+  \ {
+  \   'command': ale#path#CdString(ale#path#Simplify(g:dir . '/../eslint-test-files'))
+  \     . (has('win32') ? 'node.exe ' : '')
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ' --stdin --stdin-filename %s'
+  \     . ' --fix'
+  \     . ' --space',
+  \ }

From f17beadb49a6e57520303ea9a10722df1be4d13e Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Mon, 29 Jun 2020 18:40:43 -0500
Subject: [PATCH 06/12] fixers/xo: support monorepos

---
 autoload/ale/handlers/xo.vim                       |  4 ++--
 test/fixers/test_xo_fixer_callback.vader           | 14 +++++++-------
 test/fixers/test_xots_fixer_callback.vader         | 14 +++++++-------
 test/xo-test-files/monorepo/node_modules/xo/cli.js |  0
 test/xo-test-files/monorepo/package.json           |  0
 test/xo-test-files/monorepo/packages/a/index.js    |  0
 test/xo-test-files/monorepo/packages/a/index.ts    |  0
 .../xo-test-files/monorepo/packages/a/package.json |  0
 8 files changed, 16 insertions(+), 16 deletions(-)
 create mode 100644 test/xo-test-files/monorepo/node_modules/xo/cli.js
 create mode 100644 test/xo-test-files/monorepo/package.json
 create mode 100644 test/xo-test-files/monorepo/packages/a/index.js
 create mode 100644 test/xo-test-files/monorepo/packages/a/index.ts
 create mode 100644 test/xo-test-files/monorepo/packages/a/package.json

diff --git a/autoload/ale/handlers/xo.vim b/autoload/ale/handlers/xo.vim
index 0bea74e4..df2659da 100644
--- a/autoload/ale/handlers/xo.vim
+++ b/autoload/ale/handlers/xo.vim
@@ -29,7 +29,7 @@ function! ale#handlers#xo#HandleJSON(buffer, lines) abort
 endfunction
 
 function! ale#handlers#xo#GetProjectRoot(buffer) abort
-    let l:package_path = ale#path#FindNearestFile(a:buffer, 'package.json')
+    let l:modules_dir = ale#path#FindNearestDirectory(a:buffer, 'node_modules')
 
-    return empty(l:package_path) ? '' : fnamemodify(l:package_path, ':p:h')
+    return empty(l:modules_dir) ? '' : fnamemodify(l:modules_dir, ':h:h')
 endfunction
diff --git a/test/fixers/test_xo_fixer_callback.vader b/test/fixers/test_xo_fixer_callback.vader
index ffbecb6c..c676bd34 100644
--- a/test/fixers/test_xo_fixer_callback.vader
+++ b/test/fixers/test_xo_fixer_callback.vader
@@ -7,39 +7,39 @@ After:
   call ale#assert#TearDownFixerTest()
 
 Execute(The xo callback should return the correct default values):
-  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.js')
+  call ale#test#SetFilename('../xo-test-files/monorepo/packages/a/index.js')
 
   AssertFixer
   \ {
   \   'read_temporary_file': 1,
   \   'command': (has('win32') ? 'node.exe ' : '')
-  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo/node_modules/xo/cli.js'))
   \     . ' --fix %t',
   \ }
 
 Execute(The xo callback should include custom xo options):
   let g:ale_javascript_xo_options = '--space'
-  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.js')
+  call ale#test#SetFilename('../xo-test-files/monorepo/packages/a/index.js')
 
   AssertFixer
   \ {
   \   'read_temporary_file': 1,
   \   'command': (has('win32') ? 'node.exe ' : '')
-  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo/node_modules/xo/cli.js'))
   \     . ' --fix %t'
   \     . ' --space',
   \ }
 
 Execute(--stdin should be used when xo is new enough):
   let g:ale_javascript_xo_options = '--space'
-  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.js')
+  call ale#test#SetFilename('../xo-test-files/monorepo/packages/a/index.js')
 
   GivenCommandOutput ['0.30.0']
   AssertFixer
   \ {
-  \   'command': ale#path#CdString(ale#path#Simplify(g:dir . '/../eslint-test-files'))
+  \   'command': ale#path#CdString(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo'))
   \     . (has('win32') ? 'node.exe ' : '')
-  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo/node_modules/xo/cli.js'))
   \     . ' --stdin --stdin-filename %s'
   \     . ' --fix'
   \     . ' --space',
diff --git a/test/fixers/test_xots_fixer_callback.vader b/test/fixers/test_xots_fixer_callback.vader
index a26ec03c..6c8b448c 100644
--- a/test/fixers/test_xots_fixer_callback.vader
+++ b/test/fixers/test_xots_fixer_callback.vader
@@ -7,39 +7,39 @@ After:
   call ale#assert#TearDownFixerTest()
 
 Execute(The xo callback should return the correct default values):
-  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.ts')
+  call ale#test#SetFilename('../xo-test-files/monorepo/packages/a/index.ts')
 
   AssertFixer
   \ {
   \   'read_temporary_file': 1,
   \   'command': (has('win32') ? 'node.exe ' : '')
-  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo/node_modules/xo/cli.js'))
   \     . ' --fix %t',
   \ }
 
 Execute(The xo callback should include custom xo options):
   let g:ale_typescript_xo_options = '--space'
-  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.ts')
+  call ale#test#SetFilename('../xo-test-files/monorepo/packages/a/index.ts')
 
   AssertFixer
   \ {
   \   'read_temporary_file': 1,
   \   'command': (has('win32') ? 'node.exe ' : '')
-  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo/node_modules/xo/cli.js'))
   \     . ' --fix %t'
   \     . ' --space',
   \ }
 
 Execute(--stdin should be used when xo is new enough):
   let g:ale_typescript_xo_options = '--space'
-  call ale#test#SetFilename('../eslint-test-files/react-app/subdir/testfile.ts')
+  call ale#test#SetFilename('../xo-test-files/monorepo/packages/a/index.ts')
 
   GivenCommandOutput ['0.30.0']
   AssertFixer
   \ {
-  \   'command': ale#path#CdString(ale#path#Simplify(g:dir . '/../eslint-test-files'))
+  \   'command': ale#path#CdString(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo'))
   \     . (has('win32') ? 'node.exe ' : '')
-  \     . ale#Escape(ale#path#Simplify(g:dir . '/../eslint-test-files/react-app/node_modules/xo/cli.js'))
+  \     . ale#Escape(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo/node_modules/xo/cli.js'))
   \     . ' --stdin --stdin-filename %s'
   \     . ' --fix'
   \     . ' --space',
diff --git a/test/xo-test-files/monorepo/node_modules/xo/cli.js b/test/xo-test-files/monorepo/node_modules/xo/cli.js
new file mode 100644
index 00000000..e69de29b
diff --git a/test/xo-test-files/monorepo/package.json b/test/xo-test-files/monorepo/package.json
new file mode 100644
index 00000000..e69de29b
diff --git a/test/xo-test-files/monorepo/packages/a/index.js b/test/xo-test-files/monorepo/packages/a/index.js
new file mode 100644
index 00000000..e69de29b
diff --git a/test/xo-test-files/monorepo/packages/a/index.ts b/test/xo-test-files/monorepo/packages/a/index.ts
new file mode 100644
index 00000000..e69de29b
diff --git a/test/xo-test-files/monorepo/packages/a/package.json b/test/xo-test-files/monorepo/packages/a/package.json
new file mode 100644
index 00000000..e69de29b

From 1991313ee734129d056a61d6daf1da2c738f8e1a Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Sat, 4 Jul 2020 14:11:16 -0500
Subject: [PATCH 07/12] xo: update docs

---
 doc/ale-typescript.txt | 27 +++++++++++++++++++++++++++
 doc/ale.txt            |  1 +
 2 files changed, 28 insertions(+)

diff --git a/doc/ale-typescript.txt b/doc/ale-typescript.txt
index 2c50d119..026d17ce 100644
--- a/doc/ale-typescript.txt
+++ b/doc/ale-typescript.txt
@@ -138,5 +138,32 @@ g:ale_typescript_tsserver_use_global     *g:ale_typescript_tsserver_use_global*
   tsserver in node_modules.
 
 
+===============================================================================
+xo                                                          *ale-typescript-xo*
+
+g:ale_typescript_xo_executable                 *g:ale_typescript_xo_executable*
+                                               *b:ale_typescript_xo_executable*
+  Type: |String|
+  Default: `'xo'`
+
+  See |ale-integrations-local-executables|
+
+
+g:ale_typescript_xo_options                       *g:ale_typescript_xo_options*
+                                                  *b:ale_typescript_xo_options*
+  Type: |String|
+  Default: `''`
+
+  This variable can be set to pass additional options to xo.
+
+
+g:ale_typescript_xo_use_global                 *g:ale_typescript_xo_use_global*
+                                               *b:ale_typescript_xo_use_global*
+  Type: |Number|
+  Default: `get(g:, 'ale_use_global_executables', 0)`
+
+  See |ale-integrations-local-executables|
+
+
 ===============================================================================
   vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:
diff --git a/doc/ale.txt b/doc/ale.txt
index cfb5beb4..817201c4 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -2997,6 +2997,7 @@ documented in additional help files.
     standard..............................|ale-typescript-standard|
     tslint................................|ale-typescript-tslint|
     tsserver..............................|ale-typescript-tsserver|
+    xo....................................|ale-typescript-xo|
   vala....................................|ale-vala-options|
     uncrustify............................|ale-vala-uncrustify|
   verilog/systemverilog...................|ale-verilog-options|

From 23ff19a162aadb048f3d5b2d4a4aa9cf3ec58a52 Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Sat, 4 Jul 2020 14:12:14 -0500
Subject: [PATCH 08/12] fixers/xo: remove unnecessary directory crawl

---
 autoload/ale/fixers/xo.vim                 | 5 +----
 autoload/ale/handlers/xo.vim               | 6 ------
 test/fixers/test_xo_fixer_callback.vader   | 3 +--
 test/fixers/test_xots_fixer_callback.vader | 3 +--
 4 files changed, 3 insertions(+), 14 deletions(-)

diff --git a/autoload/ale/fixers/xo.vim b/autoload/ale/fixers/xo.vim
index 2c8ab114..0f8f3ec6 100644
--- a/autoload/ale/fixers/xo.vim
+++ b/autoload/ale/fixers/xo.vim
@@ -28,11 +28,8 @@ function! ale#fixers#xo#ApplyFixForVersion(buffer, version, executable, options)
 
     " 0.30.0 is the first version with a working --stdin --fix
     if ale#semver#GTE(a:version, [0, 30, 0])
-        let l:project_root = ale#handlers#xo#GetProjectRoot(a:buffer)
-
         return {
-        \   'command': ale#path#CdString(l:project_root)
-        \       . l:executable
+        \   'command': l:executable
         \       . ' --stdin --stdin-filename %s'
         \       . ' --fix'
         \       . l:options,
diff --git a/autoload/ale/handlers/xo.vim b/autoload/ale/handlers/xo.vim
index df2659da..3f7c72cb 100644
--- a/autoload/ale/handlers/xo.vim
+++ b/autoload/ale/handlers/xo.vim
@@ -27,9 +27,3 @@ endfunction
 function! ale#handlers#xo#HandleJSON(buffer, lines) abort
     return ale#handlers#eslint#HandleJSON(a:buffer, a:lines)
 endfunction
-
-function! ale#handlers#xo#GetProjectRoot(buffer) abort
-    let l:modules_dir = ale#path#FindNearestDirectory(a:buffer, 'node_modules')
-
-    return empty(l:modules_dir) ? '' : fnamemodify(l:modules_dir, ':h:h')
-endfunction
diff --git a/test/fixers/test_xo_fixer_callback.vader b/test/fixers/test_xo_fixer_callback.vader
index c676bd34..a473606e 100644
--- a/test/fixers/test_xo_fixer_callback.vader
+++ b/test/fixers/test_xo_fixer_callback.vader
@@ -37,8 +37,7 @@ Execute(--stdin should be used when xo is new enough):
   GivenCommandOutput ['0.30.0']
   AssertFixer
   \ {
-  \   'command': ale#path#CdString(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo'))
-  \     . (has('win32') ? 'node.exe ' : '')
+  \   'command': (has('win32') ? 'node.exe ' : '')
   \     . ale#Escape(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo/node_modules/xo/cli.js'))
   \     . ' --stdin --stdin-filename %s'
   \     . ' --fix'
diff --git a/test/fixers/test_xots_fixer_callback.vader b/test/fixers/test_xots_fixer_callback.vader
index 6c8b448c..5c7fa1d1 100644
--- a/test/fixers/test_xots_fixer_callback.vader
+++ b/test/fixers/test_xots_fixer_callback.vader
@@ -37,8 +37,7 @@ Execute(--stdin should be used when xo is new enough):
   GivenCommandOutput ['0.30.0']
   AssertFixer
   \ {
-  \   'command': ale#path#CdString(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo'))
-  \     . (has('win32') ? 'node.exe ' : '')
+  \   'command': (has('win32') ? 'node.exe ' : '')
   \     . ale#Escape(ale#path#Simplify(g:dir . '/../xo-test-files/monorepo/node_modules/xo/cli.js'))
   \     . ' --stdin --stdin-filename %s'
   \     . ' --fix'

From 4edfac4db64debcfd33d894f169d0c1dc6dc48a4 Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Tue, 19 Jan 2021 22:16:10 -0600
Subject: [PATCH 09/12] xo: inline filetype handling

---
 ale_linters/javascript/xo.vim |  4 ++--
 ale_linters/typescript/xo.vim |  4 ++--
 autoload/ale/fixers/xo.vim    | 13 ++-----------
 autoload/ale/handlers/xo.vim  | 32 +++++++++++++++++++++++++-------
 4 files changed, 31 insertions(+), 22 deletions(-)

diff --git a/ale_linters/javascript/xo.vim b/ale_linters/javascript/xo.vim
index 5b206df8..9cc1dc69 100644
--- a/ale_linters/javascript/xo.vim
+++ b/ale_linters/javascript/xo.vim
@@ -3,7 +3,7 @@
 
 call ale#linter#Define('javascript', {
 \   'name': 'xo',
-\   'executable': {b -> ale#handlers#xo#GetExecutable(b, 'javascript')},
-\   'command': {b -> ale#handlers#xo#GetLintCommand(b, 'javascript')},
+\   'executable': {b -> ale#handlers#xo#GetExecutable(b)},
+\   'command': {b -> ale#handlers#xo#GetLintCommand(b)},
 \   'callback': 'ale#handlers#xo#HandleJSON',
 \})
diff --git a/ale_linters/typescript/xo.vim b/ale_linters/typescript/xo.vim
index 13ae0cf7..2e25ba4c 100644
--- a/ale_linters/typescript/xo.vim
+++ b/ale_linters/typescript/xo.vim
@@ -1,6 +1,6 @@
 call ale#linter#Define('typescript', {
 \   'name': 'xo',
-\   'executable': {b -> ale#handlers#xo#GetExecutable(b, 'typescript')},
-\   'command': {b -> ale#handlers#xo#GetLintCommand(b, 'typescript')},
+\   'executable': {b -> ale#handlers#xo#GetExecutable(b)},
+\   'command': {b -> ale#handlers#xo#GetLintCommand(b)},
 \   'callback': 'ale#handlers#xo#HandleJSON',
 \})
diff --git a/autoload/ale/fixers/xo.vim b/autoload/ale/fixers/xo.vim
index 0f8f3ec6..dcf4c737 100644
--- a/autoload/ale/fixers/xo.vim
+++ b/autoload/ale/fixers/xo.vim
@@ -2,17 +2,8 @@
 " Description: Fixing files with XO.
 
 function! ale#fixers#xo#Fix(buffer) abort
-    let l:filetype = getbufvar(a:buffer, '&filetype')
-    let l:type = ''
-
-    if l:filetype =~# 'javascript'
-        let l:type = 'javascript'
-    elseif l:filetype =~# 'typescript'
-        let l:type = 'typescript'
-    endif
-
-    let l:executable = ale#handlers#xo#GetExecutable(a:buffer, l:type)
-    let l:options = ale#handlers#xo#GetOptions(a:buffer, l:type)
+    let l:executable = ale#handlers#xo#GetExecutable(a:buffer)
+    let l:options = ale#handlers#xo#GetOptions(a:buffer)
 
     return ale#semver#RunWithVersionCheck(
     \   a:buffer,
diff --git a/autoload/ale/handlers/xo.vim b/autoload/ale/handlers/xo.vim
index 3f7c72cb..2439b4f9 100644
--- a/autoload/ale/handlers/xo.vim
+++ b/autoload/ale/handlers/xo.vim
@@ -6,21 +6,39 @@ call ale#Set('typescript_xo_executable', 'xo')
 call ale#Set('typescript_xo_use_global', get(g:, 'ale_use_global_executables', 0))
 call ale#Set('typescript_xo_options', '')
 
-function! ale#handlers#xo#GetExecutable(buffer, type) abort
-    return ale#node#FindExecutable(a:buffer, a:type . '_xo', [
+function! ale#handlers#xo#GetExecutable(buffer) abort
+    let l:filetype = getbufvar(a:buffer, '&filetype')
+    let l:type = ''
+
+    if l:filetype =~# 'javascript'
+        let l:type = 'javascript'
+    elseif l:filetype =~# 'typescript'
+        let l:type = 'typescript'
+    endif
+
+    return ale#node#FindExecutable(a:buffer, l:type . '_xo', [
     \   'node_modules/xo/cli.js',
     \   'node_modules/.bin/xo',
     \])
 endfunction
 
-function! ale#handlers#xo#GetLintCommand(buffer, type) abort
-    return ale#Escape(ale#handlers#xo#GetExecutable(a:buffer, a:type))
-    \   . ale#Pad(ale#handlers#xo#GetOptions(a:buffer, a:type))
+function! ale#handlers#xo#GetLintCommand(buffer) abort
+    return ale#Escape(ale#handlers#xo#GetExecutable(a:buffer))
+    \   . ale#Pad(ale#handlers#xo#GetOptions(a:buffer))
     \   . ' --reporter json --stdin --stdin-filename %s'
 endfunction
 
-function! ale#handlers#xo#GetOptions(buffer, type) abort
-    return ale#Var(a:buffer, a:type . '_xo_options')
+function! ale#handlers#xo#GetOptions(buffer) abort
+    let l:filetype = getbufvar(a:buffer, '&filetype')
+    let l:type = ''
+
+    if l:filetype =~# 'javascript'
+        let l:type = 'javascript'
+    elseif l:filetype =~# 'typescript'
+        let l:type = 'typescript'
+    endif
+
+    return ale#Var(a:buffer, l:type . '_xo_options')
 endfunction
 
 " xo uses eslint and the output format is the same

From 5fd5fa53051c3514917974d0ba57f18eb50dd37e Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Tue, 19 Jan 2021 23:08:10 -0600
Subject: [PATCH 10/12] linters/xo: fix tests

---
 test/command_callback/test_xo_command_callback.vader   | 3 ++-
 test/command_callback/test_xots_command_callback.vader | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/test/command_callback/test_xo_command_callback.vader b/test/command_callback/test_xo_command_callback.vader
index 7a38b2b1..1aa4c3f1 100644
--- a/test/command_callback/test_xo_command_callback.vader
+++ b/test/command_callback/test_xo_command_callback.vader
@@ -1,8 +1,9 @@
 Before:
   call ale#assert#SetUpLinterTest('javascript', 'xo')
-  call ale#test#SetFilename('testfile.js')
+  call ale#test#SetFilename('testfile.jsx')
   unlet! b:executable
 
+  set filetype=javascriptreact
   runtime autoload/ale/handlers/xo.vim
 
 After:
diff --git a/test/command_callback/test_xots_command_callback.vader b/test/command_callback/test_xots_command_callback.vader
index c614ad59..cc38ff02 100644
--- a/test/command_callback/test_xots_command_callback.vader
+++ b/test/command_callback/test_xots_command_callback.vader
@@ -1,8 +1,9 @@
 Before:
   call ale#assert#SetUpLinterTest('typescript', 'xo')
-  call ale#test#SetFilename('testfile.ts')
+  call ale#test#SetFilename('testfile.tsx')
   unlet! b:executable
 
+  set filetype=typescriptreact
   runtime autoload/ale/handlers/xo.vim
 
 After:

From 03bd494fd42181f111ee56387a1d40639b42672e Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Tue, 19 Jan 2021 23:07:33 -0600
Subject: [PATCH 11/12] linters/xo: prefer function shorthand

---
 ale_linters/javascript/xo.vim | 4 ++--
 ale_linters/typescript/xo.vim | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/ale_linters/javascript/xo.vim b/ale_linters/javascript/xo.vim
index 9cc1dc69..5e04ad5c 100644
--- a/ale_linters/javascript/xo.vim
+++ b/ale_linters/javascript/xo.vim
@@ -3,7 +3,7 @@
 
 call ale#linter#Define('javascript', {
 \   'name': 'xo',
-\   'executable': {b -> ale#handlers#xo#GetExecutable(b)},
-\   'command': {b -> ale#handlers#xo#GetLintCommand(b)},
+\   'executable': function('ale#handlers#xo#GetExecutable'),
+\   'command': function('ale#handlers#xo#GetLintCommand'),
 \   'callback': 'ale#handlers#xo#HandleJSON',
 \})
diff --git a/ale_linters/typescript/xo.vim b/ale_linters/typescript/xo.vim
index 2e25ba4c..6f4ee50c 100644
--- a/ale_linters/typescript/xo.vim
+++ b/ale_linters/typescript/xo.vim
@@ -1,6 +1,6 @@
 call ale#linter#Define('typescript', {
 \   'name': 'xo',
-\   'executable': {b -> ale#handlers#xo#GetExecutable(b)},
-\   'command': {b -> ale#handlers#xo#GetLintCommand(b)},
+\   'executable': function('ale#handlers#xo#GetExecutable'),
+\   'command': function('ale#handlers#xo#GetLintCommand'),
 \   'callback': 'ale#handlers#xo#HandleJSON',
 \})

From 451e99341ea2abf48ec2e7318748e688a9a93b90 Mon Sep 17 00:00:00 2001
From: Charles B Johnson <mail@cbjohnson.info>
Date: Tue, 19 Jan 2021 23:07:55 -0600
Subject: [PATCH 12/12] xo: refactor to function

---
 autoload/ale/handlers/xo.vim | 29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/autoload/ale/handlers/xo.vim b/autoload/ale/handlers/xo.vim
index 2439b4f9..c63278c0 100644
--- a/autoload/ale/handlers/xo.vim
+++ b/autoload/ale/handlers/xo.vim
@@ -7,14 +7,7 @@ call ale#Set('typescript_xo_use_global', get(g:, 'ale_use_global_executables', 0
 call ale#Set('typescript_xo_options', '')
 
 function! ale#handlers#xo#GetExecutable(buffer) abort
-    let l:filetype = getbufvar(a:buffer, '&filetype')
-    let l:type = ''
-
-    if l:filetype =~# 'javascript'
-        let l:type = 'javascript'
-    elseif l:filetype =~# 'typescript'
-        let l:type = 'typescript'
-    endif
+    let l:type = ale#handlers#xo#GetType(a:buffer)
 
     return ale#node#FindExecutable(a:buffer, l:type . '_xo', [
     \   'node_modules/xo/cli.js',
@@ -29,14 +22,7 @@ function! ale#handlers#xo#GetLintCommand(buffer) abort
 endfunction
 
 function! ale#handlers#xo#GetOptions(buffer) abort
-    let l:filetype = getbufvar(a:buffer, '&filetype')
-    let l:type = ''
-
-    if l:filetype =~# 'javascript'
-        let l:type = 'javascript'
-    elseif l:filetype =~# 'typescript'
-        let l:type = 'typescript'
-    endif
+    let l:type = ale#handlers#xo#GetType(a:buffer)
 
     return ale#Var(a:buffer, l:type . '_xo_options')
 endfunction
@@ -45,3 +31,14 @@ endfunction
 function! ale#handlers#xo#HandleJSON(buffer, lines) abort
     return ale#handlers#eslint#HandleJSON(a:buffer, a:lines)
 endfunction
+
+function! ale#handlers#xo#GetType(buffer) abort
+    let l:filetype = getbufvar(a:buffer, '&filetype')
+    let l:type = 'javascript'
+
+    if l:filetype =~# 'typescript'
+        let l:type = 'typescript'
+    endif
+
+    return l:type
+endfunction