MarkdownBear: Add validate-links plugin

Closes coala#924

bears/markdown/MarkdownBear.py

@@ -21,15 +21,16 @@ class MarkdownBear:
 
     LANGUAGES = {'Markdown'}
     REQUIREMENTS = {NpmRequirement('remark-cli', '2'),
-                    NpmRequirement('remark-lint', '5')}
+                    NpmRequirement('remark-lint', '5'),
+                    NpmRequirement('remark-validate-links', '5')}
     AUTHORS = {'The coala developers'}
     AUTHORS_EMAILS = {'[email protected]'}
     LICENSE = 'AGPL-3.0'
     CAN_FIX = {'Formatting'}
 
     _output_regex = re.compile(
         r'\s*(?P<line>\d+):(?P<column>\d+)'
-        r'\s*(?P<severity>warning)\s*(?P<message>.*)')
+        r'\s*(?P<severity>warning)\s*(?P<message>.+?)(?:  .*|\n|$)')
 
     @staticmethod
     @deprecate_settings(bullets='markdown_bullets',
@@ -127,22 +128,23 @@ def create_arguments(filename, file, config_file,
             'ruleSpaces': horizontal_rule_spaces,       # Bool
             'ruleRepetition': horizontal_rule_repeat,   # int
         }
-        remark_configs_plugins = {}
+        remark_lint_configs = {}
 
         if max_line_length:
-            remark_configs_plugins['maximumLineLength'] = max_line_length
+            remark_lint_configs['maximumLineLength'] = max_line_length
 
         config_json = json.dumps(remark_configs_settings)
         # Remove { and } as remark adds them on its own
         settings = config_json[1:-1]
 
-        args = ['--no-color', '--quiet', '--setting', settings]
+        args = [filename, '--no-color', '--quiet', '--setting', settings]
 
-        if remark_configs_plugins:
-            config_json = json.dumps(remark_configs_plugins)
-            plugins = 'lint=' + config_json[1:-1]
-            args += ['--use', plugins]
+        if remark_lint_configs:
+            config_json = json.dumps(remark_lint_configs)
+            lint = 'lint=' + config_json[1:-1]
+            args += ['--use', lint]
 
+        args += ['--use', 'validate-links']
         return args
 
     def process_output(self, output, filename, file):

package.json

@@ -19,6 +19,7 @@
     "ramllint": ">=1.2.2 <1.2.4 || >=1.2.5 <1.3.0",
     "remark-cli": "~2",
     "remark-lint": "~5",
+    "remark-validate-links": "~5",
     "standard": "~7",
     "stylelint": "~7",
     "stylint": "~1.5.9",

tests/markdown/MarkdownBearTest.py

@@ -22,6 +22,16 @@
 2. nopqrstuvwxyz
 """
 
+test_file4 = """# Hello
+
+Read more [This link does not exist](#world).
+"""
+
+test_file5 = """# world
+
+Read more [This link exists](#world).
+"""
+
 MarkdownBearTest = verify_local_bear(MarkdownBear,
                                      valid_files=(test_file2,),
                                      invalid_files=(test_file1,))
@@ -52,6 +62,19 @@ def test_invalid_message(self):
         with prepare_file(content, None) as (file, fname):
             with execute_bear(self.uut, fname, file) as results:
                 self.assertEqual(results[0].message,
-                                 'Line must be at most 10 characters'
-                                 '  maximum-line-length  remark-lint')
+                                 'Line must be at most 10 characters')
+                self.assertEqual(results[0].severity, RESULT_SEVERITY.NORMAL)
+
+    def test_invalid_link(self):
+        content = test_file4.splitlines()
+        with prepare_file(content, None) as (file, fname):
+            with execute_bear(self.uut, fname, file) as results:
+                self.assertEqual(results[0].message,
+                                 'Link to unknown heading: `world`')
                 self.assertEqual(results[0].severity, RESULT_SEVERITY.NORMAL)
+
+    def test_valid_link(self):
+        content = test_file5.splitlines()
+        with prepare_file(content, None) as (file, fname):
+            with execute_bear(self.uut, fname, file) as results:
+                self.assertEqual(results, [])