ActionView::Template::Error: Can't resolve image into URL: undefined method `[]' for nil:NilClass答案

【问题标题】：ActionView::Template::Error: Can't resolve image into URL: undefined method `[]' for nil:NilClassActionView::Template::Error: Can't resolve image into URL: undefined method `[]' for nil:NilClass
【发布时间】：2020-05-20 14:15:32
【问题描述】：

使用：红宝石 2.4.0p0 导轨 5.2.3 在运行我的测试用例时：有和错误：

我的测试用例是这样的：

require 'test_helper'

class SubscriptionsControllerTest < ActionDispatch::IntegrationTest

  test "Can reach to index " do
    get subscriptions_url
    assert_response :success
  end

结束

错误：

SubscriptionsControllerTest#test_Can_reach_to_index_:
ActionView::Template::Error: Can't resolve image into URL: undefined method `[]' for nil:NilClass
    app/views/subscriptions/index.html.erb:43:in `_app_views_subscriptions_index_html_erb__900758959545617488_70234463713200'
    test/controllers/subscriptions_controller_test.rb:6:in `block in <class:SubscriptionsControllerTest>'

但手动打开 ui 时图像加载正确。你能建议什么是错的。在视图中有 image_tag 在第 43 行。

 <%= image_tag 'tukacad_1.png', alt: '', class: "img-responsive" %>

【问题讨论】：

标签： html ruby-on-rails-3 ruby-on-rails-5 ruby-2.4

【解决方案1】：

在 application.rb 或 test.rb 里面写下下面这行

config.serve_static_assets = true

也运行

rails assets:precompile

【讨论】：