Simple Mail Catcher for rails.

README.md

Update your ./bin/dev script with the following code.

__gems=("foreman" "sinatra" "gserver" "sinatra-contrib" "byebug")

for gem in "${__gems[@]}"; do
    if ! gem list "$gem" -i --silent; then
        echo "Installing $gem..."
        gem install "$gem"
    fi
done

# Check for 'mail:' directive in Procfile.dev
if ! grep -q "^mail:" Procfile.dev; then
    echo "mail: export RACK_ENV=development && ruby lib/fakemail.rb" >> Procfile.dev
    echo "Added 'mail:' directive to Procfile.dev."
fi

if [ ! -f lib/fakemail.rb ]; then
    # Download fakemail.rb to the lib/ directory
    curl "https://gist.githubusercontent.com/metacritical/4540736752dbf97b07084b7ee640c934/raw/3a90e7e48dd0bc6151f01c0f12495fa8a2b1d88a/fakemail.rb" -o lib/fakemail.rb
    echo "Downloaded fakemail.rb to lib/ directory."
fi

if [ ! -f bin/connect_byebug ]; then
    # Download connect_byebug to the bin/ directory
    curl "https://gist.githubusercontent.com/metacritical/4540736752dbf97b07084b7ee640c934/raw/3a90e7e48dd0bc6151f01c0f12495fa8a2b1d88a/connect_byebug" -o bin/connect_byebug
    chmod +x bin/connect_byebug
    echo "Downloaded conect_byebug to bin/ directory."
fi

exec foreman start -f Procfile.dev "$@"

Update config/environments/development.rb

 config.action_mailer.delivery_method = :smtp
 config.action_mailer.smtp_settings = { address: '127.0.0.1', port: 2525 }

As soon as you will run the ./bin/dev script it will automatically download and install gems and download the fakemail.rb to lib. Even update the Procfile.dev you only need to configure the above two files thats it.

The debugger is attached on 8989 which can be connected to using the bin/connect_byebug script given here.

connect_byebug

#!/bin/bash

if [ $# -ne 1 ]; then
  echo "Usage: $0 <port>"
  exit 1
fi

port="$1"
byebug -R localhost:$port

fakemail.rb

#!/usr/bin/env ruby

require 'sinatra'
require 'gserver'
require 'mail'
require 'fileutils'
require 'logger'
require 'sinatra/reloader' if development?

set :environment, :development
logger = Logger.new(STDOUT)

if ENV.fetch('RACK_ENV') == 'development'
  require 'byebug'
  require 'byebug/core'
  begin
    Byebug.start_server 'localhost', ENV.fetch('BYEBUG_SERVER_PORT', 8989).to_i
    logger.info "Byebug server started on PORT: 8989"
  rescue Errno::EADDRINUSE
    logger.warn 'Byebug server already running'
  end
end

module EmailStorage
  @emails = []
  @trash = []

  def self.add_email(email)
    @emails << email
  end

  def self.emails
    @emails
  end

  def self.trash
    @trash
  end

  def self.delete_email(index)
    @trash.push(@emails.delete_at(index))
  end

   def self.delete_trash(index)
    @trash.delete_at(index)
  end
end


#PID Cleanup
%x[rm -rf tmp/pids/*.pid]

PID_FILE = 'tmp/pids/smtp_server.pid'

# Simple SMTP Server class
class SimpleSMTPServer < GServer
  def start
    super
    write_pid_file
  end

  def shutdown
    super
    delete_pid_file
  end

  def serve(io)
    io.print "220 Welcome to SimpleSMTPServer\r\n"
    helo = io.gets
    io.print "250 Great, let's start\r\n"

    from = io.gets
    io.print "250 Ok\r\n"

    to = io.gets
    io.print "250 Ok\r\n"

    io.print "354 End data with <CR><LF>.<CR><LF>\r\n"
    email_data = ""
    loop do
      line = io.gets
      break if line == ".\r\n"
      email_data += line
    end

    email = Mail.read_from_string(email_data)
    EmailStorage.add_email({
      from: email.from,
      to: email.to,
      subject: email.subject,
      body: email.body.decoded,
      date: email.date
    })

    io.print "250 Ok: queued\r\n"
    io.print "221 Bye\r\n"
  end

private

  def write_pid_file
    FileUtils.mkdir_p(File.dirname(PID_FILE))
    File.write(PID_FILE, Process.pid.to_s)
    end

  def delete_pid_file
    File.delete(PID_FILE) if File.exist?(PID_FILE)
  end
end


def server_running?
  return false unless File.exist?(PID_FILE)

  pid = File.read(PID_FILE).to_i
  Process.kill(0, pid)
  true
rescue Errno::ESRCH
  false
end


Signal.trap('INT')  { smtp_server.shutdown }
Signal.trap('TERM') { smtp_server.shutdown }

if server_running?
  puts "Server is already running. Exiting."
  exit(1)
else
  # Start SMTP Server in a separate thread
  sleep 1
  Thread.new do
    smtp_server = SimpleSMTPServer.new(2525)
    logger.info "Simple SMTP Server listenining on localhost @ 2525 "
    smtp_server.start
    smtp_server.join
  end
end


# Sinatra routes
get '/' do
  @emails = EmailStorage.emails
  @trash = EmailStorage.trash
  erb :index, layout: :app_layout
end

get '/emails/:id' do
  @emails = EmailStorage.emails
  @trash = EmailStorage.trash
  @email = @emails[params[:id].to_i]
  erb :show_email, layout: :app_layout
end

post '/delete/' do
  params[:email_id].keys.each do |id|
    EmailStorage.delete_email(id.to_i)
  end
  redirect '/'
end

get '/trash' do
  @emails = EmailStorage.emails
  @trash = EmailStorage.trash
  erb :trash, layout: :app_layout
end

post '/delete_trash/' do
  EmailStorage.delete_trash(params[:id].to_i)
  redirect '/trash'
end

post '/empty_trash' do
  EmailStorage.trash.clear

  redirect '/'
end

get '/custom.css' do
  erb :custom_css
end


__END__



@@ index
<table class="table table-striped table-hover">
  <tbody>
    <!-- inbox header -->
    <tr>
      <td>
        <button class="btn btn-outline-primary">
          <input type="checkbox" class="all" title="select all" onclick="toggleCheckboxes(this)"> All
        </button>      </td>
      <td></td>
      <td></td>
      <td></td>
    </tr>
    <!-- inbox item -->
    <form action="/delete/" method="post">
    <% @emails.reverse.each_with_index do |email, index| %>
    <tr>
    <td>
      <label>
        <input type="checkbox" name="email_id[<%= index %>]" >
      </label> <span class="name text-truncate"><%= email[:from][0] %></span>
    </td>
    <td>
      <a class="row clickable-row" href="/emails/<%= index %>">
        <span class="subject"><%= email[:subject] %></span>
      </a>
    </td>
    <td>
      <span class="badge"><%= email[:date].to_date %></span>
    </td>
    <td>
      <button type="submit" class="btn btn-sm" name="email_id[<%= index %>]">🗑️ </button>
    </td>
    <span class="float-right fa fa-paperclip"></span></td>
    </tr>
    <% end %>
    </form>
    <!-- inbox item end-->
  </tbody>
</table>


@@ trash
<table class="table table-striped table-hover">
  <tbody>
    <!-- inbox header -->
    <tr>
      <td>
        <btn class="btn btn-outline-primary">
          <input type="checkbox" class="all" title="select all" onclick="toggleCheckboxes(this)"> All
        </btn>
      </td>
      <td></td>
      <td></td>
      <td></td>
    </tr>
    <!-- inbox item -->
    <form action="/delete_trash/" method="post">
    <% @trash.reverse.each_with_index do |email, index| %>
    <tr>
    <td>
      <label>
        <input type="checkbox" name="email_id[<%= index %>]">
      </label> <span class="name text-truncate"><%= email[:from][0] %></span>
    </td>
    <td>
      <a class="row clickable-row" href="/emails/<%= index %>">
        <span class="subject"><%= email[:subject] %></span>
      </a>
    </td>
    <td>
      <span class="badge"><%= email[:date].to_date %></span>
    </td>
    <td>
      <button type="submit" class="btn btn-sm">🗑️ </button>
    </td>
    <span class="float-right fa fa-paperclip"></span></td>
  </tr>
  <% end %>
  <!-- inbox item end-->
    </form>
  </tbody>
</table>


@@ show_email
<p>From: <%= @email[:from] %></p>
<p>To: <%= @email[:to] %></p>
<p>Subject: <%= @email[:subject] %></p>
<p><%= @email[:body] %></p>
<a href="/">Back to Inbox</a>

@@ show_trash
<div class="main-content">
  <h3>Trash</h3>
  <% @trash.reverse.each_with_index do |email, index| %>
       <div class="email-item">
            <strong>From:</strong> <%= email[:from][0] %><br>
            <strong>Subject:</strong><%= email[:subject] %><br>
            <p> <a href="/emails/<%= index %>">View</a> </p>

            <form action="/delete_trash/<%= index %>" method="post">
              <button type="submit">Delete</button>
            </form>
      </div>
  <% end %>
  <a href="/trash">Back to Trash</a>
</div>

@@ app_layout
<head>
  <title>FakeMail</title>
  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4.0.0/dist/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<link rel="stylesheet" href="/custom.css">
</head>
<body>
  <script>
   function toggleCheckboxes(allCheckbox) {
     const isChecked = allCheckbox.checked;
     document.querySelectorAll('input[name^="email_id"]').forEach(checkbox => checkbox.checked = isChecked);
   }
  </script>
  <!------ START ----->
<div class="container-fluid py-3">
    <div class="row">
        <div class="col-md-2">
            <div class="btn-group w-100">
                <h1><span class="badge bg-warning">📩 MailCapture </span></h1>
            </div>
        </div>
        <div class="col-md-10">
        </div>
    </div>
    <hr>
    <div class="row">
        <!--left-->
        <aside class="col-sm-3 col-md-2 pb-3">
            <form action="/empty_trash" method="post">
              <button type="submit" class="btn btn-danger btn-sm btn-block">
                <i class="fa fa-edit"></i> Empty Trash
              </button>
            </form>

            <hr>
            <ul class="nav nav-pills flex-column">
              <li class="active"><a href="/">
                <span class="badge badge-primary float-right">
                  <%= @emails.count %>
                </span>📥 Inbox
              </a>
              </li>
              <li>
                <a href="/trash">
                  <span class="badge badge-primary float-right">
                    <%= @trash.count %>
                  </span>🗑 Trash
                </a>
              </li>
            </ul>
            <hr>
        </aside>
        <!--main-->
        <div class="col-sm-9 col-md-10">
            <!-- tabs -->
            <ul class="nav nav-tabs border-0">
                <li class="nav-item">
                    <a class="nav-link active" href="#inbox" data-toggle="tab">
                        <i class="fa fa-inbox mr-1"></i> <%= request.path_info == '/' ? 'Inbox' : 'Trash' %>
                    </a>
                </li>
            </ul>
            <!-- tab panes -->
            <div class="tab-content py-4">
                <div class="tab-pane in active" id="inbox">
                  <%= yield %>
                </div>
            </div>
            <div class="row-md-12">
                <div class="card card-body text-right">
                    <small>Last updated: 5/01/2024: 3:02 PM</small>
                </div>
            </div>
        </div>
    </div>
</div>
<!-------- END --------->
</body>

@@ custom_css
.clickable-row {
    display: block;
    color: inherit; /* Ensures text color is not changed */
    text-decoration: none; /* Removes underline from links */
}

.clickable-row:hover {
    text-decoration: none; /* Optional: Removes underline on hover */
    background-color: #f5f5f5; /* Optional: Change background on hover */
}

Preview.md

Preview