Add missing flag 'testOnReturn'

types/generic-pool/generic-pool-tests.ts

@@ -29,6 +29,7 @@ const opts = {
     min: 2,
     maxWaitingClients: 2,
     testOnBorrow: true,
+    testOnReturn: true,
     acquireTimeoutMillis: 100,
     fifo: true,
     priorityRange: 5,

types/generic-pool/index.d.ts

@@ -38,6 +38,7 @@ export interface Options {
     min?: number;
     maxWaitingClients?: number;
     testOnBorrow?: boolean;
+    testOnReturn?: boolean;
     acquireTimeoutMillis?: number;
     fifo?: boolean;
     priorityRange?: number;