表单中的第一个参数不能包含 nil 或为空 Hartl 的 Rails 5 教程

Question

我在 Hartl 的教程中碰壁了。下面的测试给了我 "First argument in form cannot contain nil or be empty":

require 'test_helper'

class UsersEditTest < ActionDispatch::IntegrationTest

  def setup
    @user = users(:michael)
  end

  test "unsuccessful edit" do
    get edit_user_path(@user)
    assert_template 'users/edit'
    patch user_path(@user), params: { user: { name:  "",
                                              email: "foo@invalid",
                                              password:              "foo",
                                              password_confirmation: "bar" } }

    assert_template 'users/edit'
  end
end

这是我定义更新方法的控制器操作：

 class UsersController < ApplicationController

  def show
    @user = User.find(params[:id])
  end

  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)
    if @user.save
      log_in @user
      flash[:success] = "Welcome to the Sample App!"
      redirect_to @user
    else
      render 'new'
    end
  end

  def update
    @user = User.find(params[:id])
    if @user.update_attributes(user_params)
      # Handle a successful update.
    else
      render 'edit'
    end
  end

  private

    def user_params
      params.require(:user).permit(:name, :email, :password,
                                   :password_confirmation)
    end
end

最后 html 表格：

<% provide(:title, "Edit user") %>
<h1>Update your profile</h1>

<div class="row">
  <div class="col-md-6 col-md-offset-3">
    <%= form_for(@user) do |f| %>
      <%= render 'shared/error_messages' %>

      <%= f.label :name %>
      <%= f.text_field :name, class: 'form-control' %>

      <%= f.label :email %>
      <%= f.email_field :email, class: 'form-control' %>

      <%= f.label :password %>
      <%= f.password_field :password, class: 'form-control' %>

      <%= f.label :password_confirmation, "Confirmation" %>
      <%= f.password_field :password_confirmation, class: 'form-control' %>

      <%= f.submit "Save changes", class: "btn btn-primary" %>
    <% end %>

    <div class="gravatar_edit">
      <%= gravatar_for @user %>
      <a href="http://gravatar.com/emails" target="_blank" rel='noopener'>change</a>
    </div>
  </div>
</div>

可能是什么原因？我确保@user 已正确初始化。

Answer 1

您的 UsersController 中似乎缺少一个 edit 操作，它会为您初始化一个 @user 实例变量：

def edit
  @user = User.find(params[:id])
end

表单中的第一个参数不能包含 nil 或为空 Hartl 的 Rails 5 教程

First argument in form cannot contain nil or be empty Hartl's Rails 5 Tutorial

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