A function to find DraftJS Entity

findEntity.js

export const getEntitiesByLogic = ({ editorState, findEntity }) => {
  const content = editorState.getCurrentContent();
  const entities = [];
  content.getBlocksAsArray().forEach(block => {
    let selectedEntity = null;
    block.findEntityRanges(
      character => {
        if (character.getEntity() !== null) {
          const entityKey = character.getEntity();
          const entity = content.getEntity(entityKey);
          const entityData = entity.getData();
          const entityType = entity.getType();
          // If our logic is successful
          if (
            findEntity({ type: entityType, data: entityData })
          ) {
            // set data
            selectedEntity = {
              entityKey,
              blockKey: block.getKey(),
              entity: content.getEntity(character.getEntity())
            };
            return true;
          }
        }
        return false;
      },
      (start, end) => {
        // We are using this function because in most of the scenarios when using entity, 
        // we need start and end position of the entity as well which we only get here
        entities.push({ ...selectedEntity, start, end });
      }
    );
  });
  return entities;
};

const findEntity = ({ type, data }) => {
  return type === 'mention' && entityData.id === 1;
}

//We use the above function like this:
const entities = findEntitiesByLogic({editorState, findEntity});

//Result that we get:
const results = [{  
  entityKey: "myEntityKey",
  blockKey: "myBlockKey",
  entity: EntityObject,
  start: 4,
  end: 10
}]