Refactor running of local Node programs with a helper function

autoload/ale/node.vim

@@ -0,0 +1,22 @@
+" Author: w0rp <devw0rp@gmail.com>
+" Description: Functions for working with Node executables.
+
+" Given a buffer number, a base variable name, and a list of paths to search
+" for in ancestor directories, detect the executable path for a Node program.
+"
+" The use_global and executable options for the relevant program will be used.
+function! ale#node#FindExecutable(buffer, base_var_name, path_list) abort
+    if ale#Var(a:buffer, a:base_var_name . '_use_global')
+        return ale#Var(a:buffer, a:base_var_name . '_executable')
+    endif
+
+    for l:path in a:path_list
+        let l:executable = ale#path#FindNearestFile(a:buffer, l:path)
+
+        if !empty(l:executable)
+            return l:executable
+        endif
+    endfor
+
+    return ale#Var(a:buffer, a:base_var_name . '_executable')
+endfunction