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cyberfox/post_test.rb

Created March 10, 2017 09:37
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  1. cyberfox created this gist Mar 10, 2017.
    68 changes: 68 additions & 0 deletions post_test.rb
    View file
    Original file line number Diff line number Diff line change
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    require 'test_helper'

    # ActiveRecord::Schema.define(version: 20170310085807) do
    # create_table "forums", force: :cascade do |t|
    # t.string "title"
    # t.integer "posts_count"
    # t.datetime "created_at", null: false
    # t.datetime "updated_at", null: false
    # end
    #
    # create_table "posts", force: :cascade do |t|
    # t.string "subject"
    # t.integer "forum_id"
    # t.text "body"
    # t.datetime "created_at", null: false
    # t.datetime "updated_at", null: false
    # end
    # end
    #
    #
    # class Forum < ApplicationRecord
    # has_many :posts
    # end
    #
    # class Post < ApplicationRecord
    # belongs_to :forum, counter_cache: true
    # end

    class PostTest < ActiveSupport::TestCase
    setup do
    @first = Forum.create(title: "The first forum.")
    @second = Forum.create(title: "The other forum.")

    @post = Post.create(subject: "The message.", body: "Nothing important.")
    @post.forum = @first
    @post.save
    end

    test "Repeatedly assigning the association increases the counter_cache count." do
    5.times do
    @post.forum = @second
    @post.reload
    end

    # We never saved the post, the first forum should have 1, and the second forum should have none.
    assert_equal [1, 0], [@first.reload.posts_count, @second.reload.posts_count]
    # Expected: [1, 0]
    # Actual: [-4, 5]
    end

    test "The counter_cache gets updated when an association is assigned, not saved" do
    # The first forum correctly has 1 post.
    assert_equal 1, @first.reload.posts_count

    # Perhaps we should move the post?
    @post.forum = @second
    # Nah. Note, we have not saved the post.
    @post.reload

    # The reload reset the forum id in the post.
    assert_equal @first.id, @post.forum_id

    # So the posts_count should not have increased, because we never saved the changed post.
    assert_equal 1, @first.reload.posts_count
    # Expected: 1
    # Actual: 0
    end
    end