feat(filter): Adds $nor operator.

Author: ryasmi

docs/filter.md

@@ -6,6 +6,7 @@ Operator | Description
 --- | ---
 [$and](https://docs.mongodb.com/manual/reference/operator/query/and/#op._S_and) | Includes entities where all of the specified filters are true.
 [$or](https://docs.mongodb.com/manual/reference/operator/query/or/#op._S_or) | Includes entities where some of the specified filters are true.
+[$nor](https://docs.mongodb.com/manual/reference/operator/query/nor/#op._S_nor) | Includes entities where some of the specified filters are false.
 [$not](https://docs.mongodb.com/manual/reference/operator/query/no/#op._S_no) | Includes entities where a specified filter is not true.
 [$eq](https://docs.mongodb.com/manual/reference/operator/query/eq/#op._S_eq) | Includes entities where the value of a given property is equal to the specified value.
 [$ne](https://docs.mongodb.com/manual/reference/operator/query/ne/#op._S_ne) | Includes entities where the value of a given property is not equal to the specified value.
@@ -49,6 +50,14 @@ The filter below is comprehensive example using all of the operators.
           }
         }
       ]
+    },
+    ,
+    {
+      "$nor": [
+        {
+          "stringProp4": "string value 6"
+        }
+      ]
     }
   ]
 }

src/tests/utils/filterTest.ts

@@ -72,6 +72,11 @@ export default (opts: Opts) => {
     await opts.assertFirstEntityFilter({ $or: [{ stringProp: 'a' }, { numberProp: 1 }] });
   });
 
+  it('should filter correctly when using $nor operator', async () => {
+    await createTestEntities();
+    await opts.assertFirstEntityFilter({ $nor: [{ stringProp: 'b' }, { numberProp: 2 }] });
+  });
+
   it('should filter correctly when using $not operator', async () => {
     await createTestEntities();
     await opts.assertFirstEntityFilter({ stringProp: { $not: { $eq: 'b' } } });

src/types/Filter.ts

@@ -24,10 +24,15 @@ export interface OrFilter<Entity> {
   readonly $or: Filter<Entity>[];
 }
 
+export interface NorFilter<Entity> {
+  readonly $nor: Filter<Entity>[];
+}
+
 export type Filter<Entity> = (
   EntityFilter<Entity> |
   AndFilter<Entity> |
-  OrFilter<Entity>
+  OrFilter<Entity> |
+  NorFilter<Entity>
 );
 
 export default Filter;

src/utils/createPaginationFilter/index.ts

@@ -1,7 +1,7 @@
 import * as atob from 'atob';
 import { get, mapValues } from 'lodash';
 // tslint:disable-next-line:no-unused
-import Filter, { AndFilter, NotFilter, OrFilter } from '../../types/Filter';
+import Filter, { AndFilter, NorFilter, NotFilter, OrFilter } from '../../types/Filter';
 import Pagination from '../../types/Pagination';
 import Sort from '../../types/Sort';