Schema Cache Improvements (#5612)

* Cache Improvements

* improve tests

* more tests

* clean-up

* test with singlecache

* ensure indexes exists

* remove ALL_KEYS

* Add Insert Test

* enableSingleSchemaCache default true

* Revert "enableSingleSchemaCache default true"

This reverts commit 323e7130fb8f695e3ca44ebf9b3b1d38905353da.

* further optimization

* refactor enforceFieldExists

* coverage improvements

* improve tests

* remove flaky test

* cleanup

* Learned something new

spec/PostgresStorageAdapter.spec.js

@@ -114,6 +114,33 @@ describe_only_db('postgres')('PostgresStorageAdapter', () => {
       })
       .catch(done);
   });
+
+  it('getClass if exists', async () => {
+    const schema = {
+      fields: {
+        array: { type: 'Array' },
+        object: { type: 'Object' },
+        date: { type: 'Date' },
+      },
+    };
+    await adapter.createClass('MyClass', schema);
+    const myClassSchema = await adapter.getClass('MyClass');
+    expect(myClassSchema).toBeDefined();
+  });
+
+  it('getClass if not exists', async () => {
+    const schema = {
+      fields: {
+        array: { type: 'Array' },
+        object: { type: 'Object' },
+        date: { type: 'Date' },
+      },
+    };
+    await adapter.createClass('MyClass', schema);
+    await expectAsync(adapter.getClass('UnknownClass')).toBeRejectedWith(
+      undefined
+    );
+  });
 });
 
 describe_only_db('postgres')('PostgresStorageAdapter shutdown', () => {