test: unit test for fecs fixer, fecs command

test/command_callback/test_fecs_command_callback.vader

@@ -0,0 +1,8 @@
+Before:
+  call ale#assert#SetUpLinterTest('javascript', 'fecs')
+
+After:
+  call ale#assert#TearDownLinterTest()
+
+Execute(The default command should be correct):
+  AssertLinter 'fecs', ale#Escape('fecs') . ' check --colors=false --rule=true %t'

test/fixers/test_fecs_fixer_callback.vader

@@ -0,0 +1,26 @@
+Before:
+  call ale#assert#SetUpFixerTest('javascript', 'fecs')
+  runtime autoload/ale/handlers/fecs.vim
+
+After:
+  call ale#assert#TearDownFixerTest()
+
+Execute(The fecs fixer should respect to g:ale_javascript_fecs_executable):
+  let g:ale_javascript_fecs_executable = 'fecs_paths/fecs'
+  let g:ale_javascript_fecs_use_global = 1
+  silent cd ../command_callback
+  let g:dir = getcwd()
+
+  AssertEqual
+  \ {
+  \   'command': ale#Escape(g:ale_javascript_fecs_executable) . ' format --replace=true %t',
+  \   'read_temporary_file': 1,
+  \ },
+  \ ale#fixers#fecs#Fix(bufnr(''))
+
+Execute(The fecs fixer should return 0 when executable not found):
+  let g:ale_javascript_fecs_executable = 'fecs-invalid'
+  let g:ale_javascript_fecs_use_global = 1
+  AssertEqual
+  \ 0,
+  \ ale#fixers#fecs#Fix(bufnr(''))