screepCode/src/modules/util.ts

export function FindCapacity(creep: Creep) {
    return creep.room.find(FIND_STRUCTURES, {
        filter: (structure: StructureSpawn | StructureExtension) => {
            let type = structure.structureType;
            return (
                (type == STRUCTURE_EXTENSION ||
                    type == STRUCTURE_SPAWN) &&
                    structure.store.getFreeCapacity(RESOURCE_ENERGY) as number > 0
            )
        }
    })
}