`$.query` is broken in `join` / `having` on mongo driver

[ForkKILLET]

Code:

const words = await this.ctx.database
  .join(
    { message: 'w-message', word: 'w-message-word' },
    ({ message, word }) => $.and(
      $.eq(message.id, word.messageId),
      $.query(message, {
        ...guildQuery,
        ...userQuery,
        ...durationQuery,
      })
    )
  )
  .project(['word.word'])
  .execute()

Error:

MongoServerError: An object representing an expression must have exactly one field: { $expr: true, platform: "onebot", guildId: "*********", timestamp: {} }

Cause:

• $.query evaluates to { $expr, ...query }

• the join query is assigned to sel.args[0].having and handled by (Builder#modifier -> Builder#eval ->)Builder#transformEvalExpr

• $expr falls through, causing the Mongo error

  • however, $expr ($.quote) in where queries is handled correctly, by Builder#query)

Possible fix (untested):

if ('$expr' in query) {
  const { $expr, ...restQuery } = query
  return { $and: [{ $expr }, this.transformEvalExpr(restQuery, group)] }
}