Include coverage in spec matrix

.github/workflows/rubocop.yml

@@ -1,3 +1,4 @@
+# CAUTION: There's probably a way to refactor this nicely. PR welcome.
 # NOTE: When changing minimal version of Ruby or Rubocop, change all of them
 
 name: CI
@@ -7,7 +8,7 @@ on: [push, pull_request]
 jobs:
   ast_specs:
     name: >-
-      AST | ${{ matrix.rubocop }} | ${{ matrix.ruby }} (${{ matrix.os }})
+      ${{ matrix.title || 'AST' }} | ${{ matrix.rubocop }} | ${{ matrix.ruby }} (${{ matrix.os }})
     runs-on: ${{ matrix.os }}-latest
     env:
       # See https://github.com/tmm1/test-queue#environment-variables
@@ -18,10 +19,13 @@ jobs:
         os: [ ubuntu ]
         ruby: [ 2.4, 2.5, 2.6, 2.7, head ]
         rubocop: [ master ]
+        coverage: [ null ]
+        title: [ null ]
         include:
           - { os: windows, rubocop: master, ruby: mingw }
           - { rubocop: '0.84.0', ruby: 2.4, os: ubuntu }
           - { rubocop: '0.84.0', ruby: head, os: ubuntu }
+          - { rubocop: '0.84.0', ruby: 2.4, os: ubuntu, coverage: true, title: 'Cov' }
 
     steps:
       - name: windows misc
@@ -49,10 +53,20 @@ jobs:
           git clone https://github.com/rubocop-hq/rubocop.git ../rubocop
           chmod +x ../rubocop/exe/rubocop
           cd ../rubocop && bundle install --jobs 3 --retry 3
+      - name: code coverage
+        if: matrix.coverage
+        uses: paambaati/codeclimate-action@v2.6.0
+        env:
+          CC_TEST_REPORTER_ID: '758a8228862932dc8afa9144c4a5bc5dfe29c2f7dde1b7734175bad49ee310e7'
+          COVERAGE: 'true'
+        with:
+          coverageCommand: bundle exec rake spec
+          debug: true
       - name: spec
+        if: matrix.coverage != true
         run:  bundle exec rake spec
       - name: internal_investigation
-        if: matrix.os != 'windows'
+        if: "matrix.os != 'windows' && matrix.coverage != true"
         run:  bundle exec rake internal_investigation
   rubocop_specs:
     name: >-