Add yaml swaglint linter (#771)

* Add yaml swaglint linter

test/command_callback/test_swaglint_command_callback.vader

@@ -0,0 +1,36 @@
+Before:
+  runtime ale_linters/yaml/swaglint.vim
+  call ale#test#SetDirectory('/testplugin/test/command_callback')
+
+After:
+  call ale#linter#Reset()
+  let g:ale_yaml_swaglint_executable = 'swaglint'
+  let g:ale_yaml_swaglint_use_global = 0
+
+Execute(The yaml swaglint command callback should return the correct default string):
+  AssertEqual 'swaglint',
+  \ ale_linters#yaml#swaglint#GetExecutable(bufnr(''))
+  AssertEqual 'swaglint -r compact --stdin',
+  \ ale_linters#yaml#swaglint#GetCommand(bufnr(''))
+
+Execute(The yaml swaglint command callback should be configurable):
+  let g:ale_yaml_swaglint_executable = '~/.local/bin/swaglint'
+  AssertEqual '~/.local/bin/swaglint',
+  \ ale_linters#yaml#swaglint#GetExecutable(bufnr(''))
+  AssertEqual '~/.local/bin/swaglint -r compact --stdin',
+  \ ale_linters#yaml#swaglint#GetCommand(bufnr(''))
+
+Execute(The yaml swaglint command callback should allow a global installation to be used):
+  let g:ale_yaml_swaglint_executable = '/usr/local/bin/swaglint'
+  let g:ale_yaml_swaglint_use_global = 1
+  AssertEqual '/usr/local/bin/swaglint',
+  \ ale_linters#yaml#swaglint#GetExecutable(bufnr(''))
+  AssertEqual '/usr/local/bin/swaglint -r compact --stdin',
+  \ ale_linters#yaml#swaglint#GetCommand(bufnr(''))
+
+Execute(The yaml swaglint command callback should allow a local installation to be used):
+  call ale#test#SetFilename('swaglint_paths/docs/swagger.yaml')
+  AssertEqual g:dir . '/swaglint_paths/node_modules/.bin/swaglint',
+  \ ale_linters#yaml#swaglint#GetExecutable(bufnr(''))
+  AssertEqual g:dir . '/swaglint_paths/node_modules/.bin/swaglint -r compact --stdin',
+  \ ale_linters#yaml#swaglint#GetCommand(bufnr(''))

test/handler/test_swaglint_handler.vader

@@ -0,0 +1,58 @@
+Before:
+  runtime ale_linters/yaml/swaglint.vim
+
+Execute(The swaglint handler should parse lines correctly):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 1,
+  \     'col': 1,
+  \     'text': 'Missing required property: info (sway_object_missing_required_property)',
+  \     'type': 'E',
+  \   },
+  \   {
+  \     'lnum': 6,
+  \     'col': 9,
+  \     'text': 'Not a valid response definition (sway_one_of_missing)',
+  \     'type': 'E',
+  \   },
+  \   {
+  \     'lnum': 7,
+  \     'col': 11,
+  \     'text': 'Missing required property: description (sway_object_missing_required_property)',
+  \     'type': 'E',
+  \   },
+  \   {
+  \     'lnum': 7,
+  \     'col': 11,
+  \     'text': 'Missing required property: $ref (sway_object_missing_required_property)',
+  \     'type': 'E',
+  \   },
+  \   {
+  \     'lnum': 1,
+  \     'col': 10,
+  \     'text': 'Expected type string but found type integer (sway_invalid_type)',
+  \     'type': 'E',
+  \   },
+  \   {
+  \     'lnum': 1,
+  \     'col': 10,
+  \     'text': 'No enum match for: 2 (sway_enum_mismatch)',
+  \     'type': 'E',
+  \   },
+  \   {
+  \     'lnum': 14,
+  \     'col': 3,
+  \     'text': 'Definition is not used: #/definitions/Foo (sway_unused_definition)',
+  \     'type': 'W',
+  \   },
+  \ ],
+  \ ale_linters#yaml#swaglint#Handle(347, [
+  \   'swagger.yaml: error @ 1:1 - Missing required property: info (sway_object_missing_required_property)',
+  \   'swagger.yaml: error @ 6:9 - Not a valid response definition (sway_one_of_missing)',
+  \   'swagger.yaml: error @ 7:11 - Missing required property: description (sway_object_missing_required_property)',
+  \   'swagger.yaml: error @ 7:11 - Missing required property: $ref (sway_object_missing_required_property)',
+  \   'swagger.yaml: error @ 1:10 - Expected type string but found type integer (sway_invalid_type)',
+  \   'swagger.yaml: error @ 1:10 - No enum match for: 2 (sway_enum_mismatch)',
+  \   'swagger.yaml: warning @ 14:3 - Definition is not used: #/definitions/Foo (sway_unused_definition)',
+  \ ])