如何在Heroku部署中发现并调试500个错误，该错误在开发模式下似乎可以正常工作？

Question

I figure I'll post this here as it'll hopefully save someone else the hours of tracing through each commit to see what the problem is. I hadn't pushed to heroku in a few weeks and when I did the app crashed with a 500 html message. no more information than that and the logs had nothng helpful to say whatsoever. nothing seemed atypical and nothing was out of the ordinary. what was the solution?

Answer 1

An unimplemented method in a controller, I had added a method new into a controller I hadn't implemented, I had no template or code in the method and it caused a 500 error on every page in the app, if your heroku push fails check all your controllers for unimplemented methods:

class ContactTablesController < ApplicationController
    before_action :signed_in_user

  # respond_to :html, :js

  # def new #I added this to implement it later, started doing something else
  # end     # and forgot about it, uncommenting these lines brings the entire heroku app
            # down resulting in 500 errors

  def create
    # pp params[:contact_table] + " create"
    @user = User.find(params[:contact_table][:contact_id])
    current_user.add_contact!(@user)
    respond_to do |format|
      format.html { redirect_to @user }
      format.js
    end
  end

  def destroy
    # pp params[:contact_table] + " destroy"
    @user = ContactTable.find(params[:id]).contact
    @id = ContactTable.where('user_id is ? AND contact_id is ?', current_user.id, @user.id).first.id 
    current_user.remove_contact!(@user)
    respond_to do |format|
      format.html { redirect_to @user }
      format.js
    end
  end
end

I realise a lot of people might know that this happens but I didn't and it took a while of going through the code to notice it. hope it can help someone else.