Untuck tests out of __tests__ directories, colocate with program files

src/normalizers/notification.test.ts

@@ -0,0 +1,17 @@
+import { Record as ImmutableRecord } from 'immutable';
+
+import { normalizeNotification } from './notification';
+
+describe('normalizeNotification()', () => {
+  it('normalizes an empty map', () => {
+    const notification = {};
+    const result = normalizeNotification(notification);
+
+    expect(ImmutableRecord.isRecord(result)).toBe(true);
+    expect(result.type).toEqual('');
+    expect(result.account).toBe(null);
+    expect(result.target).toBe(null);
+    expect(result.status).toBe(null);
+    expect(result.id).toEqual('');
+  });
+});