RequirementsInfoExtractor.py: Extract Project Dependency Info

Extract Project Dependency Info
from requirements.txt.

Closes #154

coala_quickstart/info_extractors/RequirementsInfoExtractor.py

@@ -0,0 +1,33 @@
+from requirements import parse
+
+from coala_quickstart.info_extraction.InfoExtractor import InfoExtractor
+from coala_quickstart.info_extraction.Information import (
+    ProjectDependencyInfo, VersionInfo)
+
+
+class RequirementsInfoExtractor(InfoExtractor):
+    supported_file_globs = ("requirements.txt",)
+
+    supported_information_kinds = (
+        ProjectDependencyInfo, VersionInfo)
+
+    def parse_file(self, fname, file_content):
+        parsed_file = []
+        with open(fname, 'r') as f:
+            parsed_file = parse(f)
+        return parsed_file
+
+    def find_information(self, fname, parsed_file):
+        results = []
+        for dependency in parsed_file:
+            results.append(
+                ProjectDependencyInfo(
+                    fname,
+                    dependency.name,
+                    version=VersionInfo(fname,
+                                        ''.join(str(i) for i in
+                                                dependency.specs[0]))
+                )
+            )
+
+        return results

tests/info_extractors/RequirementsInfoExtractorTest.py

@@ -0,0 +1,55 @@
+import os
+import unittest
+
+from coala_quickstart.info_extractors.RequirementsInfoExtractor import (
+    RequirementsInfoExtractor)
+from coala_quickstart.info_extraction.Information import (
+    ProjectDependencyInfo, VersionInfo)
+from tests.TestUtilities import generate_files
+
+
+test_file = """
+# This is the file to test requirements extractor.
+# It should not parse this line.
+Babel<=2.3.4
+Flask==0.11.1 # Everything after # must be ignored.
+Django>=1.5 # This is a comment.
+Jinja~2.9.6
+# Neither this.
+"""
+
+
+class RequirementsInfoExtractorTest(unittest.TestCase):
+    def setUp(self):
+        self.current_dir = os.getcwd()
+
+    def test_extracted_information(self):
+
+        with generate_files(
+            ['requirements'],
+            [test_file],
+                self.current_dir) as gen_file:
+
+            self.uut = RequirementsInfoExtractor(
+                ['requirements'],
+                self.current_dir)
+            extracted_info = self.uut.extract_information()
+            extracted_info = extracted_info[
+                os.path.normcase('requirements')
+            ]
+
+            information_types = extracted_info.keys()
+            self.assertIn("ProjectDependencyInfo", information_types)
+            dep_info = extracted_info['ProjectDependencyInfo']
+            self.assertEqual(len(dep_info), 4)
+
+            requirements_list = [('Babel', '<=2.3.4'),
+                                 ('Flask', '==0.11.1'),
+                                 ('Django', '>=1.5'),
+                                 ('Jinja', '~2.9.6'), ]
+
+            deps = [(dep.value, dep.version.value) for dep in dep_info]
+            self.assertNotIn(('ignore_this', '<=2.4'), deps)
+
+            for requirement in requirements_list:
+                self.assertIn(requirement, deps)