fix(mongoose): Connection's aren't truly thenable

types/mongoose/index.d.ts

@@ -1,4 +1,4 @@
-// Type definitions for Mongoose 5.0.1
+// Type definitions for Mongoose 5.0.2
 // Project: http://mongoosejs.com/
 // Definitions by: horiuchi <https://github.com/horiuchi>
 //                 sindrenm <https://github.com/sindrenm>
@@ -97,7 +97,10 @@ declare module "mongoose" {
   export function createConnection(): Connection;
   export function createConnection(uri: string,
     options?: ConnectionOptions
-  ): Connection;
+  ): Connection & {
+    then: Promise<Connection>["then"];
+    catch: Promise<Connection>["catch"];
+  };
 
   /**
    * Disconnects all connections.
@@ -403,9 +406,6 @@ declare module "mongoose" {
 
     /** Expose the possible connection states. */
     static STATES: any;
-
-    then: Promise<Connection>["then"];
-    catch: Promise<Connection>["catch"];
   }
 
   /*

types/mongoose/mongoose-tests.ts

@@ -131,6 +131,13 @@ mongoose.Connection.STATES.hasOwnProperty('');
 conn1.on('data', cb);
 conn1.addListener('close', cb);
 
+// The connection returned by useDb is *not* thenable.
+// From https://github.com/DefinitelyTyped/DefinitelyTyped/pull/26057#issuecomment-396150819
+const getDB = async (tenant: string)=> {
+  return conn1.useDb(tenant);
+};
+
+
 /*
  * section error/validation.js
  * http://mongoosejs.com/docs/api.html#error-validation-js