Draft - Adding matchmaker callback for advanced filtering

[ironohki]

Summary

Enables the option to pass a filter callback when defining a room in Colyseus.

DRAFT - Awaiting code review and approval.

TODO - Unit tests.

Author Code-Review Questions Questions

The following questions are also noted as inline comments in the code.

• I defined a new type in interfaces.ts. Types are not defined here, but I was not sure of a more appropriate location to define the time that is referenced throughout this process.
• I added an optional property to the findOne method and the Query class. This seemed like a minimally intrusive approach, but I considered the new value could be added to the IRoomListingData interface, which is passed as a partial.
• I used the name "filterMethod" as the user-facing property to define a callback used for filtering, while I defined the type name as "filterCallback" elsewhere in the code. Requesting feedback on Colyseus expectations for user-facing and internal variable naming.

Changes

/MatchMater.ts

• Passes filterCallback to findOne method in awaitRoomAvailable

/matchmaker/RegisteredHandler.ts

• Receives filterCallback from server define if provided, uses null if not provided.

/matchmaker/driver/Query.ts

• Adds logic to use filterCallback if it is defined.
• If filterCallback is null, use existing behavior.
• If filterCallback is defined, first manually check locked, name and private.
• If locked, name and private pass, provide instance options and room options to filterCallback.
• If filterCallback returns strict boolean false, return false for this room filter check.
• Proceed with room filter loop process.

/matchmaker/driver/index.ts

• Adds filterMethod as a property to Query method when FindOne method is called.

/matchmaker/driver/interfaces.ts

• Adds filterMethod as an optional property to the findOne interface.
• Defines the type FilterMethod as function with clientOptions and roomOptions optional properties, that returns strict boolean, or null.

Intended implementation example

const filterMethod = (instanceOptions: any, roomOptions: any): boolean => {
  return 
    instanceOptions.alpha !== roomOptions.beta && 
    instanceOptions.gamma === roomOptions.gamma;
} 

initializeGameServer: (gameServer) => {
  gameServer.define('MyRoom', MyRoom).filterBy(['alpha','beta','gamma']).filterMethod(filterCallback);
}