add missing test for _get_related_readable

Author: dantownsend

tests/example_app/tables.py

@@ -2,8 +2,7 @@
 
 from piccolo.table import Table
 from piccolo.columns import Varchar, ForeignKey, Integer, Numeric, Text
-from piccolo.columns.choices import Choice
-
+from piccolo.columns.readable import Readable
 
 ###############################################################################
 # Simple example
@@ -12,6 +11,10 @@
 class Manager(Table):
     name = Varchar(length=50)
 
+    @classmethod
+    def get_readable(cls) -> Readable:
+        return Readable(template="%s", columns=[cls.name])
+
 
 class Band(Table):
     name = Varchar(length=50)

tests/table/instance/test_get_related_readable.py

@@ -0,0 +1,22 @@
+from tests.example_app.tables import Band
+from tests.base import DBTestCase
+
+
+class TestGetRelatedReadable(DBTestCase):
+    def test_get_related_readable(self):
+        """
+        Make sure you can get the `Readable` representation for related object
+        from another object instance.
+        """
+        self.insert_row()
+
+        response = Band.select(
+            Band.name, Band._get_related_readable(Band.manager)
+        ).run_sync()
+
+        self.assertEqual(
+            response, [{"name": "Pythonistas", "manager_readable": "Guido"}]
+        )
+
+        # TODO Need to make sure it can go two levels deep ...
+        # e.g. Concert._get_related_readable(Concert.band_1.manager)