fixed most of the test cases

src/documents/tests/test_parsers.py

@@ -0,0 +1,50 @@
+from tempfile import TemporaryDirectory
+from unittest import mock
+
+from django.test import TestCase
+
+from documents.parsers import get_parser_class
+
+
+class TestParserDiscovery(TestCase):
+
+    @mock.patch("documents.parsers.document_consumer_declaration.send")
+    def test__get_parser_class_1_parser(self, m, *args):
+        class DummyParser(object):
+            pass
+
+        m.return_value = (
+            (None, lambda _: {"weight": 0, "parser": DummyParser}),
+        )
+
+        self.assertEqual(
+            get_parser_class("doc.pdf"),
+            DummyParser
+        )
+
+    @mock.patch("documents.parsers.document_consumer_declaration.send")
+    def test__get_parser_class_n_parsers(self, m, *args):
+
+        class DummyParser1(object):
+            pass
+
+        class DummyParser2(object):
+            pass
+
+        m.return_value = (
+            (None, lambda _: {"weight": 0, "parser": DummyParser1}),
+            (None, lambda _: {"weight": 1, "parser": DummyParser2}),
+        )
+
+        self.assertEqual(
+            get_parser_class("doc.pdf"),
+            DummyParser2
+        )
+
+    @mock.patch("documents.parsers.document_consumer_declaration.send")
+    def test__get_parser_class_0_parsers(self, m, *args):
+        m.return_value = ((None, lambda _: None),)
+        with TemporaryDirectory() as tmpdir:
+            self.assertIsNone(
+                get_parser_class("doc.pdf")
+            )