add tests for rendering foreign key and unique constraints (#596)

(cherry picked from commit efe2eba)

.changes/unreleased/Under the Hood-20230511-144429.yaml

@@ -0,0 +1,6 @@
+kind: Under the Hood
+body: test foreign key + unique constraint rendering
+time: 2023-05-11T14:44:29.374015-04:00
+custom:
+  Author: michelleark
+  Issue: "7417"

tests/functional/adapter/test_constraints.py

@@ -14,14 +14,15 @@
 
 _expected_sql_snowflake = """
 create or replace transient table <model_identifier> (
-    id integer not null primary key,
+    id integer not null primary key references <foreign_key_model_identifier> (id) unique,
     color text,
     date_day text
 ) as ( select
         id,
         color,
         date_day from
     (
+    -- depends_on: <foreign_key_model_identifier>
     select
         'blue' as color,
         1 as id,
@@ -113,15 +114,17 @@ def expected_sql(self):
     color text,
     date_day text,
     primary key (id),
-    constraint strange_uniqueness_requirement unique (color, date_day)
+    constraint strange_uniqueness_requirement unique (color, date_day),
+    foreign key (id) references <foreign_key_model_identifier> (id)
 ) as ( select
         id,
         color,
         date_day from
     (
+    -- depends_on: <foreign_key_model_identifier>
     select
-        1 as id,
         'blue' as color,
+        1 as id,
         '2019-01-01' as date_day
     ) as model_subq
 );