CircleCI rerun failed tests in RSpec with Knapsack Pro Queue Mode. Thanks to that you can rerun only failed tests instead of rerunning the whole CI build. https://docs.knapsackpro.com/ruby/circleci/ & https://knapsackpro.com

.circleci-config.yml

      - run:
          name: Run tests
          command: |
            export CIRCLE_TEST_REPORTS=/tmp/test-results
            mkdir -p $CIRCLE_TEST_REPORTS

            # split slow spec files by test examples
            # https://docs.knapsackpro.com/ruby/split-by-test-examples/
            export KNAPSACK_PRO_RSPEC_SPLIT_BY_TEST_EXAMPLES=true

            # Use circleci CLI to find out if we need to run all tests or rerun failed tests
            # We are telling circleci to split the tests across 1 node to get the full list of all tests for consideration. We leave the splitting to Knapsack Pro.
            export KNAPSACK_PRO_TEST_FILE_LIST_SOURCE_FILE=/tmp/tests_to_run.txt
            circleci tests glob "spec/**/*_spec.rb" | circleci tests run --index 0 --total 1 --command ">$KNAPSACK_PRO_TEST_FILE_LIST_SOURCE_FILE xargs -n1 echo" --verbose
            
            # tell Knapsack Pro to run only tests from the file (and still use Knapsack Pro Queue Mode magic)
            bundle exec rake "knapsack_pro:queue:rspec[--format documentation --format RspecJunitFormatter --out tmp/rspec.xml]"

Demo video: https://www.youtube.com/watch?v=gf2BK_ZukUg

You should probably use the CIRCLE_NODE_TOTAL env variable rather than hard coding 1

RUNNER_TOTAL=$(($CIRCLE_NODE_TOTAL - 1))
circleci tests glob "spec/**/*_spec.rb" | circleci tests run --index 0 --total $RUNNER_TOTAL --command ">/tmp/tests_to_run.txt xargs echo" --verbose > /tmp/tests_to_run.txt

You should probably use the CIRCLE_NODE_TOTAL env variable rather than hard coding 1

RUNNER_TOTAL=$(($CIRCLE_NODE_TOTAL - 1))
circleci tests glob "spec/**/*_spec.rb" | circleci tests run --index 0 --total $RUNNER_TOTAL --command ">/tmp/tests_to_run.txt xargs echo" --verbose > /tmp/tests_to_run.txt

@sethherr That's incorrect.

You need to specify --total 1 on purpose to feed Knapsack Pro Queue API with list of all test files. Only then tests could be properly distributed across CI nodes by Knapsack Pro.

KNAPSACK_PRO_TEST_FILE_LIST_SOURCE_FILE expects list of all test files. Each CI node must provide exactly the same list of tests. That's why we use --total 1.

Ahhhh. Ok, thanks for explaining.