#2542 - Improve checkstyle project configuration

ale_linters/java/checkstyle.vim

@@ -1,6 +1,10 @@
 " Author: Devon Meunier <devon.meunier@gmail.com>
 " Description: checkstyle for Java files
 
+call ale#Set('java_checkstyle_executable', 'checkstyle')
+call ale#Set('java_checkstyle_config', 'google_checks.xml')
+call ale#Set('java_checkstyle_options', '')
+
 function! ale_linters#java#checkstyle#Handle(buffer, lines) abort
     let l:output = []
 
@@ -36,18 +40,21 @@ function! ale_linters#java#checkstyle#Handle(buffer, lines) abort
 endfunction
 
 function! ale_linters#java#checkstyle#GetCommand(buffer) abort
-    return 'checkstyle '
-    \ . ale#Var(a:buffer, 'java_checkstyle_options')
+    let l:options = ale#Var(a:buffer, 'java_checkstyle_options')
+    let l:config_option = ale#Var(a:buffer, 'java_checkstyle_config')
+    let l:config = l:options !~# '\v(^| )-c' && !empty(l:config_option)
+    \   ? ale#path#FindNearestFile(a:buffer, l:config_option)
+    \   : ''
+
+    return '%e'
+    \ . ale#Pad(l:options)
+    \ . (!empty(l:config) ? ' -c ' . ale#Escape(l:config) : '')
     \ . ' %s'
 endfunction
 
-if !exists('g:ale_java_checkstyle_options')
-    let g:ale_java_checkstyle_options = '-c /google_checks.xml'
-endif
-
 call ale#linter#Define('java', {
 \   'name': 'checkstyle',
-\   'executable': 'checkstyle',
+\   'executable': {b -> ale#Var(b, 'java_checkstyle_executable')},
 \   'command': function('ale_linters#java#checkstyle#GetCommand'),
 \   'callback': 'ale_linters#java#checkstyle#Handle',
 \   'lint_file': 1,

doc/ale-java.txt

@@ -5,14 +5,41 @@ ALE Java Integration                                         *ale-java-options*
 ===============================================================================
 checkstyle                                                *ale-java-checkstyle*
 
+g:ale_java_checkstyle_config                     *g:ale_java_checkstyle_config*
+                                                 *b:ale_java_checkstyle_config*
+
+  Type: |String|
+  Default: `'google_checks.xml'`
+
+  A path to a checkstyle configuration file.
+
+  If a configuration file is specified with |g:ale_java_checkstyle_options|,
+  it will be preferred over this setting.
+
+  The path to the configuration file can be an absolute path or a relative
+  path. ALE will search for the relative path in parent directories.
+
+
+g:ale_java_checkstyle_executable             *g:ale_java_checkstyle_executable*
+                                             *b:ale_java_checkstyle_executable*
+
+  Type: |String|
+  Default: 'checkstyle'
+
+  This variable can be changed to modify the executable used for checkstyle.
+
+
 g:ale_java_checkstyle_options                   *g:ale_java_checkstyle_options*
                                                 *b:ale_java_checkstyle_options*
 
-  Type: String
-  Default: '-c /google_checks.xml'
+  Type: |String|
+  Default: `''`
 
   This variable can be changed to modify flags given to checkstyle.
 
+  If a configuration file is specified with `-c`, it will be used instead of
+  configuration files set with |g:ale_java_checkstyle_config|.
+
 
 ===============================================================================
 javac                                                          *ale-java-javac*

test/command_callback/test_checkstyle_command_callback.vader

@@ -0,0 +1,62 @@
+Before:
+  call ale#assert#SetUpLinterTest('java', 'checkstyle')
+  call ale#test#SetFilename('dummy.java')
+
+After:
+  call ale#assert#TearDownLinterTest()
+
+Execute(The checkstyle callback should return the correct default value):
+  AssertLinter 'checkstyle', ale#Escape('checkstyle') . ' %s'
+
+Execute(The checkstyle executable should be configurable):
+  let b:ale_java_checkstyle_executable = 'foobar'
+
+  AssertLinter 'foobar', ale#Escape('foobar') . ' %s'
+
+Execute(Custom options should be supported):
+  let b:ale_java_checkstyle_options = '--foobar'
+
+  AssertLinter 'checkstyle', ale#Escape('checkstyle') . ' --foobar %s'
+
+Execute(configuration files set in _config should be supported):
+  let b:ale_java_checkstyle_config = ale#path#Simplify(g:dir . '/checkstyle_paths/other_config.xml')
+
+  AssertLinter 'checkstyle',
+  \ ale#Escape('checkstyle')
+  \ . ' -c ' . ale#Escape(ale#path#Simplify(g:dir . '/checkstyle_paths/other_config.xml'))
+  \ . ' %s'
+
+Execute(configuration files set in _options should be preferred over _config):
+  let b:ale_java_checkstyle_config = '/foo.xml'
+  let b:ale_java_checkstyle_options = '-c /bar.xml'
+
+  AssertLinter 'checkstyle', ale#Escape('checkstyle') . ' -c /bar.xml %s'
+
+  let b:ale_java_checkstyle_options = '-x -c /bar.xml'
+
+  AssertLinter 'checkstyle', ale#Escape('checkstyle') . ' -x -c /bar.xml %s'
+
+Execute(google_checks.xml should be detected automatically):
+  call ale#test#SetFilename('checkstyle_paths/test.java')
+
+  AssertLinter 'checkstyle',
+  \ ale#Escape('checkstyle')
+  \ . ' -c ' . ale#Escape(ale#path#Simplify(g:dir . '/checkstyle_paths/google_checks.xml'))
+  \ . ' %s'
+
+Execute(Other relative paths should be supported):
+  let b:ale_java_checkstyle_config = 'checkstyle_paths/other_config.xml'
+
+  AssertLinter 'checkstyle',
+  \ ale#Escape('checkstyle')
+  \ . ' -c ' . ale#Escape(ale#path#Simplify(g:dir . '/checkstyle_paths/other_config.xml'))
+  \ . ' %s'
+
+  call ale#test#SetFilename('checkstyle_paths/test.java')
+
+  let b:ale_java_checkstyle_config = 'other_config.xml'
+
+  AssertLinter 'checkstyle',
+  \ ale#Escape('checkstyle')
+  \ . ' -c ' . ale#Escape(ale#path#Simplify(g:dir . '/checkstyle_paths/other_config.xml'))
+  \ . ' %s'