FIX: Change base importer to create new Bookmark records (#9603)

Also add a spec and fixture with a mock importer that we can use to test the create_X methods of the base importer

spec/script/import_scripts/base_spec.rb

@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+require_relative '../../../script/import_scripts/base'
+
+describe ImportScripts::Base do
+  before do
+    STDOUT.stubs(:write)
+  end
+
+  class MockSpecImporter < ImportScripts::Base
+    def initialize(data)
+      super()
+      @import_data = data
+    end
+
+    def execute
+      import_users
+      import_posts
+      import_bookmarks
+    end
+
+    def import_users
+      users = @import_data[:users]
+      create_users(users) do |row|
+        { email: row[:email], id: row[:id] }
+      end
+    end
+
+    def import_posts
+      posts = @import_data[:posts]
+      create_posts(posts) do |row|
+        user_id = @lookup.user_id_from_imported_user_id(row[:user_id]) || -1
+        { user_id: user_id, raw: row[:raw], id: row[:id], title: "Test topic for post #{row[:id]}" }
+      end
+    end
+
+    def import_bookmarks
+      bookmarks = @import_data[:bookmarks]
+      create_bookmarks(bookmarks) do |row|
+        { post_id: row[:post_id], user_id: row[:user_id] }
+      end
+    end
+  end
+
+  let(:import_data) do
+    import_file = Rack::Test::UploadedFile.new(file_from_fixtures("base-import-data.json", "json"))
+    ActiveSupport::HashWithIndifferentAccess.new(JSON.parse(import_file.read))
+  end
+
+  it "creates bookmarks, posts, and users" do
+    MockSpecImporter.new(import_data).perform
+    expect(Bookmark.count).to eq(5)
+    expect(Post.count).to eq(5)
+    expect(User.where('id > 0').count).to eq(1)
+  end
+end