bears/dart: Add bear for Dart using Dart Linter

Add a bear for Dart, which is a scalable programming language.
It looks a bit like a python or javascript.

Fixes #105

.ci/deps.sh

@@ -51,3 +51,7 @@ for dep_version in "${dep_versions[@]}" ; do
 done
 
 python setup.py --help
+
+# Dart Lint commands
+wget -nc -O ~/dart-sdk.zip https://storage.googleapis.com/dart-archive/channels/stable/release/1.14.2/sdk/dartsdk-linux-x64-release.zip
+unzip -n ~/dart-sdk.zip -d ~/

bears/dart/DartLintBear.py

@@ -0,0 +1,26 @@
+import re
+
+from coalib.bearlib.abstractions.Lint import Lint
+from coalib.bears.LocalBear import LocalBear
+from coalib.results.RESULT_SEVERITY import RESULT_SEVERITY
+
+
+class DartLintBear(LocalBear, Lint):
+    executable = 'dartanalyzer'
+    output_regex = re.compile(
+        r'\[(?P<severity>error|warning)\] (?P<message>.+)\('
+        r'(?P<file_name>.+), line (?P<line>\d+),'
+        r' col (?P<column>\d+)\)')
+    severity_map = {
+        "error": RESULT_SEVERITY.MAJOR,
+        "warning": RESULT_SEVERITY.NORMAL}
+
+    def run(self, filename, file):
+        '''
+        Checks the code with ``dart-linter``.
+
+        This bear expects dart commands to be on your ``PATH``. Please ensure
+        /path/to/dart-sdk/bin is in your ``PATH``.
+        '''
+        self.arguments = '{filename}'
+        return self.lint(filename)

circle.yml

@@ -6,9 +6,11 @@ dependencies:
     - ~/coala-bears/node_modules
     - ~/.rvm/gems/ruby-2.1.5/gems/
     - ~/.RLibrary
+    - ~/dart-sdk/bin
   pre:
     - echo 'export PATH=$PATH:~/coala-bears/node_modules/.bin' >> ~/.circlerc
     - echo 'export LINTR_COMMENT_BOT=false' >> ~/.circlerc
+    - echo 'export PATH=$PATH:~/dart-sdk/bin' >> ~/.circlerc
     - sed -i '/source \/home\/ubuntu\/virtualenvs\//d' ~/.circlerc
     - nvm alias default node
   override:

tests/dart/DartLintBearTest.py

@@ -0,0 +1,32 @@
+from bears.dart.DartLintBear import DartLintBear
+from tests.LocalBearTestHelper import verify_local_bear
+
+
+good_file = """
+printNumber(num aNumber) {
+  print('The number is $aNumber.');
+}
+
+main() {
+  var answer = 42;          // The meaning of life.
+  printNumber(answer);
+}
+""".splitlines(keepends=True)
+
+
+bad_file = """
+printNumber(num aNumber) {
+  print('The number is $aNumber.')
+}
+
+main() {
+  var answer = 42;          // The meaning of life.
+  printNumber(answer)
+}
+""".splitlines(keepends=True)
+
+
+DartLintBearTest = verify_local_bear(DartLintBear,
+                                     valid_files=(good_file,),
+                                     invalid_files=(bad_file,),
+                                     tempfile_kwargs={"suffix": ".dart"})