add explicit clear rejection of

Signed-off-by: Fredrik Adelöw <freben@gmail.com>

plugins/catalog-backend/src/service/request/applyPredicateEntityFilterToQuery.test.ts

@@ -231,6 +231,12 @@ describe.each(databases.eachSupportedId())(
       ).resolves.toEqual(['service-a', 'website-c']);
     });
 
+    it('throws on $contains operator', async () => {
+      await expect(
+        query({ 'metadata.name': { $contains: 'service' } as any }),
+      ).rejects.toThrow(/\$contains operator is not supported/);
+    });
+
     it('throws on top-level primitive', async () => {
       await expect(query('bad-value' as any)).rejects.toThrow(
         /top-level primitive values are not supported/,

plugins/catalog-backend/src/service/request/applyPredicateEntityFilterToQuery.ts

@@ -209,6 +209,11 @@ function applyFieldCondition(options: {
         .andWhereRaw('?? like ? escape ?', ['value', `${escaped}%`, '\\']);
       return targetQuery.andWhere(onEntityIdField, 'in', matchQuery);
     }
+
+    if ('$contains' in value) {
+      // TODO(freben): Implement this, AT LEAST for some special cases such as tags and relations.
+      throw new InputError('The $contains operator is not supported');
+    }
   }
 
   throw new InputError(