UrlGenerationError Missing Required Key [:id] Error?

When i want to create an article. i get this error after clicking on the create article button "No route matches {:action=>"show", :controller=>"articles", :id=>nil} missing required keys: [:id]"

although i make sure there is a user who is logged in before creating the article. Here's my code:

articles_controller.rb

class ArticlesController < ApplicationController
before_action :require_user , except:[:index,:show]

def index
    @articles = Article.all
end

def new
    @article = Article.new
end

def create
    @article = Article.new(article_params)
    if @article.save
        flash[:notice] = "Your Article was Created"
    else
        render 'new'
    end
    redirect_to article_path(@article)
end

def show
    @article = Article.find(params[:id])
end

def edit
    @article = Article.find(params[:id])
end

def update
    @article = Article.find(params[:id])
    if @article.update(article_params)
        flash[:notice] = "Your Article was Updated"
        redirect_to article_path(@article)
    else
        render 'edit'
    end

end

def destroy
    @article = Article.find(params[:id])
    @article.destroy
    flash[:notice] = "Your Article was deleted"
    redirect_to articles_path(@article)
end

private

def article_params
    params.require(:article).permit(:title,:description)
end

end

users_controller.rb

class UsersController < ApplicationController
def index
    @users = User.all
end

def new
    @user = User.new
end

def create
    @user = User.new(user_params)
    if @user.save
        flash[:success] = "You Signed up successfully"
        redirect_to articles_path
    else
        render 'new'
    end

end

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

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

def update
    @user = User.find(params[:id])
    if @user.update(user_params)
        flash[:success]= "Your user was updated"
        redirect_to articles_path
    else
        render 'edit'
    end
end

private

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

end

views/new.html

    <h1>New Article</h1>
<%= form_for @article do |f| %>

<p>title<%= f.text_field :title %></p><br>
<p>description<%= f.text_area :description %></p>
<%= f.submit "Create" %>
<%end%>

here's my github repo

my github repo