refactor(javac): ale_java_javac_classpath variable supports String and List types

ale_linters/java/javac.vim

@@ -41,10 +41,15 @@ endfunction
 function! s:BuildClassPathOption(buffer, import_paths) abort
     " Filter out lines like [INFO], etc.
     let l:class_paths = filter(a:import_paths[:], 'v:val !~# ''[''')
-    call extend(
-    \   l:class_paths,
-    \   split(ale#Var(a:buffer, 'java_javac_classpath'), s:classpath_sep),
-    \)
+    let l:cls_path = ale#Var(a:buffer, 'java_javac_classpath')
+
+    if !empty(l:cls_path) && type(l:cls_path) is v:t_string
+        call extend(l:class_paths, split(l:cls_path, s:classpath_sep))
+    endif
+
+    if !empty(l:cls_path) && type(l:cls_path) is v:t_list
+        call extend(l:class_paths, l:cls_path)
+    endif
 
     return !empty(l:class_paths)
     \   ? '-cp ' . ale#Escape(join(l:class_paths, s:classpath_sep))

doc/ale-java.txt

@@ -46,7 +46,7 @@ javac                                                          *ale-java-javac*
 
 g:ale_java_javac_classpath                         *g:ale_java_javac_classpath*
                                                    *b:ale_java_javac_classpath*
-  Type: |String|
+  Type: |String| or |List|
   Default: `''`
 
   This variable can be set to change the global classpath for Java.

test/command_callback/test_javac_command_callback.vader

@@ -31,7 +31,7 @@ After:
 Execute(The javac callback should return the correct default value):
   AssertLinter 'javac', g:prefix . ' -d ' . ale#Escape('TEMP_DIR') . ' %t'
 
-Execute(The javac callback should use g:ale_java_javac_classpath correctly):
+Execute(The javac callback should use string type g:ale_java_javac_classpath correctly):
   let g:ale_java_javac_classpath = 'foo.jar'
 
   AssertLinter 'javac',
@@ -39,6 +39,14 @@ Execute(The javac callback should use g:ale_java_javac_classpath correctly):
   \   . ' -cp ' . ale#Escape('foo.jar')
   \   . ' -d ' . ale#Escape('TEMP_DIR') . ' %t'
 
+Execute(The javac callback should use list type g:ale_java_javac_classpath correctly):
+  let g:ale_java_javac_classpath = ['foo.jar']
+
+  AssertLinter 'javac',
+  \ g:prefix
+  \   . ' -cp ' . ale#Escape('foo.jar')
+  \   . ' -d ' . ale#Escape('TEMP_DIR') . ' %t'
+
 Execute(The executable should be configurable):
   let g:ale_java_javac_executable = 'foobar'
 
@@ -108,6 +116,51 @@ Execute(The javac callback should combine discovered classpaths and manual ones)
   \   . ' -d ' . ale#Escape('TEMP_DIR') . ' %t',
   \ substitute(b:command, '%e', '\=ale#Escape(''javac'')', 'g')
 
+  let g:ale_java_javac_classpath = ['configured.jar']
+  let b:command = ale_linters#java#javac#GetCommand(bufnr(''), [
+  \ '[DEBUG] Ignore this.',
+  \ '[INFO] Something we should ignore.',
+  \ '/foo/bar.jar',
+  \ '/xyz/abc.jar',
+  \], {})
+
+  AssertEqual
+  \ g:prefix
+  \   . ' -cp '
+  \   . ale#Escape(join(
+  \     [
+  \       '/foo/bar.jar',
+  \       '/xyz/abc.jar',
+  \       'configured.jar',
+  \     ],
+  \     g:cp_sep
+  \   ))
+  \   . ' -d ' . ale#Escape('TEMP_DIR') . ' %t',
+  \ substitute(b:command, '%e', '\=ale#Escape(''javac'')', 'g')
+
+  let g:ale_java_javac_classpath = ['configured.jar', 'configured2.jar']
+  let b:command = ale_linters#java#javac#GetCommand(bufnr(''), [
+  \ '[DEBUG] Ignore this.',
+  \ '[INFO] Something we should ignore.',
+  \ '/foo/bar.jar',
+  \ '/xyz/abc.jar',
+  \], {})
+
+  AssertEqual
+  \ g:prefix
+  \   . ' -cp '
+  \   . ale#Escape(join(
+  \     [
+  \       '/foo/bar.jar',
+  \       '/xyz/abc.jar',
+  \       'configured.jar',
+  \       'configured2.jar',
+  \     ],
+  \     g:cp_sep
+  \   ))
+  \   . ' -d ' . ale#Escape('TEMP_DIR') . ' %t',
+  \ substitute(b:command, '%e', '\=ale#Escape(''javac'')', 'g')
+
 Execute(The javac callback should use string type g:ale_java_javac_sourcepath correctly):
   let g:ale_java_javac_sourcepath = 'java_paths/build/gen/main'