Get all error and failed test case in MiniTest Using SimpleCov in Rails Code

I am trying to send all the failed test case error to an email whenever my rake test(Minitest) fails, Right now it shows the error and failed test case in the terminal now.

I have no clue how to capture those failed test cases errors and failed cases related info in some rails variable to and send those errors in the email.

I just want to get the error in my rails programmatically each time my test cases fail just like it shows in the terminal when I run rake test.

Explored Simplecov Github doc too, but didn't find anything

I am using these 3 gems to generate coverage report including Minitest gem too

group :test do
 gem 'simplecov'
 gem 'simplecov-cobertura'
 gem 'minitest'
end

https://github.com/colszowka/simplecov

Like this failure case in terminal

Any help would be highly appreciated.

There are multiple ways to achieve this, I will describe one of the ways. Most of the big testing libs have a concept of custom reporters or hooks around their execution lifecycle, you would want to essentially use that to trigger your email in case tests fail. In case of minitest, you should follow these examples from the minitest doc.

You should create a minitest plugin and let the minitest plugin load a custom reporter which keeps tracks of failures and sends them over an email once the test suite is finished. Your custom reporter might look something like

# minitest/email_reporter_plugin.rb

module Minitest
  class CustomEmailReporter < AbstractReporter
    attr_accessor :failures

    def initialize options
      self.failures = []
    end

    def record result
      self.failures << result if !(result.passed? || result.skipped?)
    end

    def report
      if !self.failures.empty?
          MyAwesomeEmailService.send_email(prepare_email_content)
      end
    end

    def prepare_email_content
       # Use the data in self.failures to prepare an email here and return it
    end
  end

  # code from above...
end

If you want to see what more you can do, have a look at some of the inbuilt reporters.