add end to end test for kegg annotation of virgo

backend/metagenedb/apps/catalog/management/commands/tests/test_files/virgo_kegg.tsv

+V1	K12345	ljo:LJ0360	dvvi:GSVIVP00035275001  GSVIVT00035275001; assembled CDS; K02948 small subunit ribosomal protein S11
+V2	K67890	shg:Sph21_4943	dtni:5367  ;

backend/metagenedb/apps/catalog/management/commands/tests/test_import_virgo_kegg.py

+import os
+
+from rest_framework.test import APITestCase
+
+from metagenedb.apps.catalog.models import Gene
+from metagenedb.apps.catalog.management.commands.import_virgo_genes import ImportVirgoGenes
+from metagenedb.apps.catalog.management.commands.import_virgo_kegg import ImportVirgoGeneKeggAnnotation
+from metagenedb.apps.catalog.factory.function import generate_fake_functions_db
+
+
+class TestEndToEnd(APITestCase):
+    """
+    This test depends on two files, one to create genes (gene_length) and the other for this test (kegg)
+    """
+
+    @classmethod
+    def setUpTestData(cls):
+        generate_fake_functions_db()
+        virgo_gene_length_file = os.path.join(os.path.dirname(__file__), "./test_files/virgo_gene_length.tsv")
+        loader = ImportVirgoGenes(virgo_gene_length_file)
+        loader.load_all()
+
+    def test_end_to_end(self):
+        test_file = os.path.join(os.path.dirname(__file__), "./test_files/virgo_kegg.tsv")
+        loader = ImportVirgoGeneKeggAnnotation(test_file)
+        expected_genes = {
+            'v1': {
+                'source': 'virgo',
+                'name': 'V1',
+                'functions': {
+                    'kegg': 'K12345',
+                }
+            },
+            'v2': {
+                'source': 'virgo',
+                'name': 'V2',
+                'functions': {
+                    'kegg': 'K67890',
+                }
+            },
+        }
+        loader.load_all()
+        created_genes = Gene.objects.all().prefetch_related('functions')
+        for created_gene in created_genes:
+            for key in ['source', 'name']:
+                self.assertEqual(getattr(created_gene, key), expected_genes[created_gene.gene_id][key])
+            # Check functions
+            for function in created_gene.functions.all():
+                self.assertIn(function.source, ['kegg', 'eggnog'])
+                self.assertEqual(
+                    function.function_id, expected_genes[created_gene.gene_id]['functions'][function.source]
+                )