Run ESLint fixer from project root, where possible (#3096)

* Split eslint#GetCdString from eslint#GetCommand

Move the code for finding the project root and building the cd string
into a separate function so that it can be reused in the eslint fixer.

Signed-off-by: Kevin Locke <kevin@kevinlocke.name>

* Run ESLint fixer from project root dir

To match the ESLint linter, as changed in 9ee57d43 (which I forgot to
apply to the fixer, whoops).

Fixes: #3094
Closes: #3095

Signed-off-by: Kevin Locke <kevin@kevinlocke.name>

2 files changed, 18 insertions, 10 deletions

diff --git a/autoload/ale/fixers/eslint.vim b/autoload/ale/fixers/eslint.vim
index 62e692b1..f725875c 100644
--- a/autoload/ale/fixers/eslint.vim
+++ b/autoload/ale/fixers/eslint.vim
@@ -53,7 +53,8 @@ function! ale#fixers#eslint#ApplyFixForVersion(buffer, version) abort
     " Use --fix-to-stdout with eslint_d
     if l:executable =~# 'eslint_d$' && ale#semver#GTE(a:version, [3, 19, 0])
         return {
-        \   'command': ale#node#Executable(a:buffer, l:executable)
+        \   'command': ale#handlers#eslint#GetCdString(a:buffer)
+        \       . ale#node#Executable(a:buffer, l:executable)
         \       . ale#Pad(l:options)
         \       . ' --stdin-filename %s --stdin --fix-to-stdout',
         \   'process_with': 'ale#fixers#eslint#ProcessEslintDOutput',
@@ -63,7 +64,8 @@ function! ale#fixers#eslint#ApplyFixForVersion(buffer, version) abort
     " 4.9.0 is the first version with --fix-dry-run
     if ale#semver#GTE(a:version, [4, 9, 0])
         return {
-        \   'command': ale#node#Executable(a:buffer, l:executable)
+        \   'command': ale#handlers#eslint#GetCdString(a:buffer)
+        \       . ale#node#Executable(a:buffer, l:executable)
         \       . ale#Pad(l:options)
         \       . ' --stdin-filename %s --stdin --fix-dry-run --format=json',
         \   'process_with': 'ale#fixers#eslint#ProcessFixDryRunOutput',
@@ -71,7 +73,8 @@ function! ale#fixers#eslint#ApplyFixForVersion(buffer, version) abort
     endif
 
     return {
-    \   'command': ale#node#Executable(a:buffer, l:executable)
+    \   'command': ale#handlers#eslint#GetCdString(a:buffer)
+    \       . ale#node#Executable(a:buffer, l:executable)
     \       . ale#Pad(l:options)
     \       . (!empty(l:config) ? ' -c ' . ale#Escape(l:config) : '')
     \       . ' --fix %t',
diff --git a/autoload/ale/handlers/eslint.vim b/autoload/ale/handlers/eslint.vim
index 156b939f..c7c47d78 100644
--- a/autoload/ale/handlers/eslint.vim
+++ b/autoload/ale/handlers/eslint.vim
@@ -37,11 +37,9 @@ function! ale#handlers#eslint#GetExecutable(buffer) abort
     \])
 endfunction
 
-function! ale#handlers#eslint#GetCommand(buffer) abort
-    let l:executable = ale#handlers#eslint#GetExecutable(a:buffer)
-
-    let l:options = ale#Var(a:buffer, 'javascript_eslint_options')
-
+" Given a buffer, return a command prefix string which changes directory
+" as necessary for running ESLint.
+function! ale#handlers#eslint#GetCdString(buffer) abort
     " ESLint 6 loads plugins/configs/parsers from the project root
     " By default, the project root is simply the CWD of the running process.
     " https://github.com/eslint/rfcs/blob/master/designs/2018-simplified-package-loading/README.md
@@ -50,9 +48,16 @@ function! ale#handlers#eslint#GetCommand(buffer) abort
     " Note: If node_modules not present yet, can't load local deps anyway.
     let l:modules_dir = ale#path#FindNearestDirectory(a:buffer, 'node_modules')
     let l:project_dir = !empty(l:modules_dir) ? fnamemodify(l:modules_dir, ':h:h') : ''
-    let l:cd_command = !empty(l:project_dir) ? ale#path#CdString(l:project_dir) : ''
 
-    return l:cd_command
+    return !empty(l:project_dir) ? ale#path#CdString(l:project_dir) : ''
+endfunction
+
+function! ale#handlers#eslint#GetCommand(buffer) abort
+    let l:executable = ale#handlers#eslint#GetExecutable(a:buffer)
+
+    let l:options = ale#Var(a:buffer, 'javascript_eslint_options')
+
+    return ale#handlers#eslint#GetCdString(a:buffer)
     \   . ale#node#Executable(a:buffer, l:executable)
     \   . (!empty(l:options) ? ' ' . l:options : '')
     \   . ' -f json --stdin --stdin-filename %s'