Try splitting tests into separate groups by the top-level

context/describe.

This is done by doing `rspec -fd --dry-run` and selecting only top-level descriptions

Hopefully this will make testing faster/easier to debug when there are
flakey tests.

Author: jordansissel

.github/workflows/ruby.yml

@@ -6,11 +6,29 @@ on:
     branches: [main]
 
 jobs:
+  split:
+    runs-on: ubuntu-24.04 
+    outputs:
+      rspec_groups: ${{ steps.groups.outputs.rspec_groups }}
+    steps:
+    - uses: actions/checkout@v3
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: '3.4'
+        bundler-cache: true
+    - id: groups
+      run: |
+        printf "rspec_groups<<JSON\n" >> $GITHUB_OUTPUT
+        bundle exec rspec -fd --dry-run | sed -ne '/^Finished in /q; /^\S/p' | jq -R | jq -s >> $GITHUB_OUTPUT
+        printf "JSON\n" >> $GITHUB_OUTPUT
+
   test:
     runs-on: ubuntu-22.04
+    needs: [ split ]
     strategy:
       matrix:
         ruby-version: ['2.7', '3.0', '3.1', '3.4']
+        rspec-group: ${{ fromJSON(needs.split.outputs.rspec_groups) }}
     steps:
     - run: |
         sudo apt-get update
@@ -21,10 +39,7 @@ jobs:
         ruby-version: ${{ matrix.ruby-version }}
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically
     - run: |
-        if [ ! -z "$RUNNER_DEBUG" ] ; then
-          DEBUG=1 bundle exec rspec -fd
-        else
-          bundle exec rspec
-        fi
+        [ ! -z "$RUNNER_DEBUG" ] && export DEBUG=1
+        bundle exec rspec -fd -e "${{ matrix.rspec-group }}"
       env:
         SHELL: /usr/bin/bash