Added tests for HasOneThrough eager loading

tests/sqlite/relationships/test_sqlite_has_through_relationships.py

@@ -0,0 +1,119 @@
+import unittest
+
+from build.lib.masoniteorm.collection import Collection
+from build.lib.masoniteorm.scopes import scope
+from src.masoniteorm.models import Model
+from src.masoniteorm.relationships import has_one_through
+from tests.integrations.config.database import DB
+from tests.integrations.config.database import DATABASES
+from src.masoniteorm.schema import Schema
+from src.masoniteorm.schema.platforms import SQLitePlatform
+
+
+class Port(Model):
+    __table__ = "ports"
+    __connection__ = "dev"
+    __fillable__ = ["port_id", "name", "port_country_id"]
+
+
+class Country(Model):
+    __table__ = "countries"
+    __connection__ = "dev"
+    __fillable__ = ["country_id", "name"]
+
+
+class IncomingShipment(Model):
+    __table__ = "incoming_shipments"
+    __connection__ = "dev"
+    __fillable__ = ["shipment_id", "name", "from_port_id"]
+
+    @has_one_through(None, "from_port_id", "port_country_id", "port_id", "country_id")
+    def from_country(self):
+        return [Country, Port]
+
+
+class TestRelationships(unittest.TestCase):
+    def setUp(self):
+        self.schema = Schema(
+            connection="dev",
+            connection_details=DATABASES,
+            platform=SQLitePlatform,
+        ).on("dev")
+
+        with self.schema.create_table_if_not_exists("incoming_shipments") as table:
+            table.integer("shipment_id").primary()
+            table.string("name")
+            table.integer("from_port_id")
+
+        with self.schema.create_table_if_not_exists("ports") as table:
+            table.integer("port_id").primary()
+            table.string("name")
+            table.integer("port_country_id")
+
+        with self.schema.create_table_if_not_exists("countries") as table:
+            table.integer("country_id").primary()
+            table.string("name")
+
+        if not Country.count():
+            Country.builder.new().bulk_create(
+                [
+                    {"country_id": 10, "name": "Australia"},
+                    {"country_id": 20, "name": "USA"},
+                    {"country_id": 30, "name": "Canada"},
+                    {"country_id": 40, "name": "United Kingdom"},
+                ]
+            )
+
+        if not Port.count():
+            Port.builder.new().bulk_create(
+                [
+                    {"port_id": 100, "name": "Melbourne", "port_country_id": 10},
+                    {"port_id": 200, "name": "Darwin", "port_country_id": 10},
+                    {"port_id": 300, "name": "South Louisiana", "port_country_id": 20},
+                    {"port_id": 400, "name": "Houston", "port_country_id": 20},
+                    {"port_id": 500, "name": "Montreal", "port_country_id": 30},
+                    {"port_id": 600, "name": "Vancouver", "port_country_id": 30},
+                    {"port_id": 700, "name": "Southampton", "port_country_id": 40},
+                    {"port_id": 800, "name": "London Gateway", "port_country_id": 40},
+                ]
+            )
+
+        if not IncomingShipment.count():
+            IncomingShipment.builder.new().bulk_create(
+                [
+                    {"name": "Bread", "from_port_id": 300},
+                    {"name": "Milk", "from_port_id": 100},
+                    {"name": "Tractor Parts", "from_port_id": 100},
+                    {"name": "Fridges", "from_port_id": 700},
+                    {"name": "Wheat", "from_port_id": 600},
+                    {"name": "Kettles", "from_port_id": 400},
+                    {"name": "Bread", "from_port_id": 700},
+                ]
+            )
+
+    def test_has_one_through_can_eager_load(self):
+        shipments = IncomingShipment.where("name", "Bread").with_("from_country").get()
+        self.assertEqual(shipments.count(), 2)
+
+        shipment1 = shipments.shift()
+        self.assertIsInstance(shipment1.from_country, Country)
+        self.assertEqual(shipment1.from_country.country_id, 20)
+
+        shipment2 = shipments.shift()
+        self.assertIsInstance(shipment2.from_country, Country)
+        self.assertEqual(shipment2.from_country.country_id, 40)
+
+    def test_has_one_through_eager_load_can_be_empty(self):
+        shipments = (
+            IncomingShipment.where("name", "Bread")
+            .with_(
+                "from_country",
+            )
+            .get()
+        )
+        self.assertEqual(shipments.count(), 2)
+
+    def test_has_one_through_can_get_related(self):
+        shipment = IncomingShipment.where("name", "Milk").first()
+        self.assertIsInstance(shipment.from_country, Country)
+        self.assertEqual(shipment.from_country.country_id, 10)