Add executable option for phpmd linter (resolves #1076) (#1078)

* Add executable option for phpmd linter (resolves #1076)
* Add test for phpmd executable option

ale_linters/php/phpmd.vim

@@ -1,11 +1,20 @@
-" Author: medains <https://github.com/medains>
+" Author: medains <https://github.com/medains>, David Sierra <https://github.com/davidsierradz>
 " Description: phpmd for PHP files
 
+let g:ale_php_phpmd_executable = get(g:, 'ale_php_phpmd_executable', 'phpmd')
+
 " Set to change the ruleset
 let g:ale_php_phpmd_ruleset = get(g:, 'ale_php_phpmd_ruleset', 'cleancode,codesize,controversial,design,naming,unusedcode')
 
+function! ale_linters#php#phpmd#GetExecutable(buffer) abort
+    return ale#Var(a:buffer, 'php_phpmd_executable')
+endfunction
+
 function! ale_linters#php#phpmd#GetCommand(buffer) abort
-    return 'phpmd %s text '
+    let l:executable = ale_linters#php#phpmd#GetExecutable(a:buffer)
+
+    return ale#Escape(l:executable)
+    \   . ' %s text '
     \   . ale#Var(a:buffer, 'php_phpmd_ruleset')
     \   . ' --ignore-violations-on-exit %t'
 endfunction
@@ -30,7 +39,7 @@ endfunction
 
 call ale#linter#Define('php', {
 \   'name': 'phpmd',
-\   'executable': 'phpmd',
+\   'executable_callback': 'ale_linters#php#phpmd#GetExecutable',
 \   'command_callback': 'ale_linters#php#phpmd#GetCommand',
 \   'callback': 'ale_linters#php#phpmd#Handle',
 \})

doc/ale-php.txt

@@ -121,6 +121,14 @@ g:ale_php_phpcs_use_global                         *g:ale_php_phpcs_use_global*
 ===============================================================================
 phpmd                                                           *ale-php-phpmd*
 
+g:ale_php_phpmd_executable                         *g:ale_php_phpmd_executable*
+                                                   *b:ale_php_phpmd_executable*
+  Type: |String|
+  Default: `'phpmd'`
+
+  This variable sets executable used for phpmd.
+
+
 g:ale_php_phpmd_ruleset                               *g:ale_php_phpmd_ruleset*
                                                       *b:ale_php_phpmd_ruleset*
   Type: |String|

test/command_callback/test_phpmd_command_callbacks.vader

@@ -0,0 +1,20 @@
+Before:
+  Save g:ale_php_phpmd_executable
+
+  unlet! g:ale_php_phpmd_executable
+
+  runtime ale_linters/php/phpmd.vim
+
+After:
+  Restore
+
+  call ale#linter#Reset()
+
+Execute(Custom executables should be used for the executable and command):
+  let g:ale_php_phpmd_executable = 'phpmd_test'
+
+  AssertEqual 'phpmd_test', ale_linters#php#phpmd#GetExecutable(bufnr(''))
+  AssertEqual
+  \ ale#Escape('phpmd_test')
+  \ . ' %s text cleancode,codesize,controversial,design,naming,unusedcode --ignore-violations-on-exit %t',
+  \ ale_linters#php#phpmd#GetCommand(bufnr(''))