ActiveRecord: preload for has_many through with source_type provided fails if has_many through association without source_type was specified in preload earlier.

[EnotPoloskun]

Steps to reproduce

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  gem "rails", "7.0.8"
  gem "sqlite3"
end

require "active_record"
require "minitest/autorun"
require "logger"

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
ActiveRecord::Base.logger = Logger.new($stdout)

ActiveRecord::Schema.define do
  create_table "invoices", force: :cascade, &:timestamps

  create_table "invoice_payments", force: :cascade do |t|
    t.integer "invoice_id"
    t.integer "source_id"
    t.string "source_type"
  end

  create_table "checks", force: :cascade, &:timestamps

  create_table "charges", force: :cascade do |t|
    t.integer "card_id"
  end

  create_table "cards", force: :cascade, &:timestamps
end

class Invoice < ActiveRecord::Base
  has_many :invoice_payments
  has_many :charges, through: :invoice_payments, source: :source, source_type: "Charge"
end

class InvoicePayment < ActiveRecord::Base
  belongs_to :invoice
  belongs_to :source, polymorphic: true
end

class Check < ActiveRecord::Base
end

class Charge < ActiveRecord::Base
  belongs_to :card
end

class Card < ActiveRecord::Base
end

class BugTest < Minitest::Test
  def test_preload
    invoice = Invoice.create!
    check = Check.create!
    card = Card.create!
    charge = Charge.create!(card: card)
    InvoicePayment.create!(invoice: invoice, source: charge)
    InvoicePayment.create!(invoice: invoice, source: check)

    assert_equal invoice, Invoice.preload(:invoice_payments).first # works
    assert_equal invoice, Invoice.preload(:charges).first # works
    assert_equal invoice, Invoice.preload(:invoice_payments, :charges).first # works
    assert_equal invoice, Invoice.preload(:charges, :invoice_payments).first # works
    assert_equal invoice, Invoice.preload({ charges: :card }, :invoice_payments).first # works
    assert_equal invoice, Invoice.preload(:invoice_payments, { charges: :card }).first # fails
  end
end

Expected behavior

Invoice.preload(:invoice_payments, { charges: :card }).first

Should return first invoice with preloaded associations provided in preload same way how

Invoice.preload({ charges: :card }, :invoice_payments).first

does. Order inside preload must not matter.

Actual behavior

Following error is raised:

ActiveRecord::AssociationNotFoundError: Association named 'card' was not found on Check; perhaps you misspelled it?

System configuration

Rails version: 7.0.8
Ruby version: 3.2.2

[EnotPoloskun]

I believe that potential workaround for that issue is defining scoped association for has_many through to use. E.g in my example Invoice model should be changed to following

class Invoice < ActiveRecord::Base
  has_many :invoice_payments
  has_many :charge_invoice_payments, -> { where(source_type: "Charge") }, class_name: "InvoicePayment"
  has_many :charges, through: :charge_invoice_payments, source: :source, source_type: "Charge"
end

and tests will pass.

[paulreece]

I can confirm the error occurs from the reproduction script on the current development branch for 7.x.

Possibly related to:
49197
49084