How can I make Mix run only specific tests from my suite of tests?

There are 5 ways to run only specific tests with Elixir

1. run a single file with mix test path_to_your_tests/your_test_file.exs
   This will run all test defined in your_test_file.exs

2. run a specific test from a specific test file by adding a colon and the line number of that test
   for example mix test path_to_your_tests/your_test_file.exs:12 will run the test at line 12 of
   your_test_file.exs

3. define a tag to exclude on your test methods

   defmodule MyTests do
       @tag disabled: true
       test "some test" do
           #testtesttest
       end
   end
   

   on the command line execute your tests like this
   mix test --exclude disabled

4. define a tag to include on your test methods

   defmodule MyTests do
       @tag mustexec: true
       test "some test" do
           #testtesttest
       end
   end
   

   on the command line execute your tests like this
   mix test --only mustexec

5. Generally exclude some tagged tests by adding this to your test/test_helper.exsfile
   ExUnit.configure exclude: [disabled: true]

Warning:
Mix has an --include directive. This directive is NOT the same as the --only directive. Include is used to break the general configuration (exclusion) from the test/test_helper.exsfile described under 4).

For some reason googling for elixir mix include testsor the like never shows up on my search results therefore I have written this entry and its answer. For more info, see the Mix documentation.