Add coverage parallelization (Synthetixio#1275)

* remove definition of NODE_OPTIONS form ci config as is already defined on package.json

* add coverage reports parallelization and upload it to codecov

* remove istanbul-combine for coverage merging

let codecov to take care of merging the reports

Author: mjlescano

.circleci/config.yml

@@ -210,6 +210,22 @@ jobs:
       - store_artifacts:
           path: test/publish/test-log.html
           destination: test-log.html
+  job-unit-tests-coverage-report:
+    working_directory: ~/repo
+    docker:
+      - image: synthetixio/docker-node:14.16-focal
+        auth:
+          username: $DOCKERHUB_USERNAME
+          password: $DOCKERHUB_TOKEN
+    steps:
+      - checkout
+      - attach_workspace:
+          at: /tmp/coverage
+      - run:
+          name: Upload coverage
+          command: |
+            cp -R /tmp/coverage/coverage-*.json .
+            bash <(curl -s https://codecov.io/bash)
   job-unit-tests-coverage:
     working_directory: ~/repo
     docker:
@@ -218,12 +234,28 @@ jobs:
           username: $DOCKERHUB_USERNAME
           password: $DOCKERHUB_TOKEN
     resource_class: large
+    parallelism: 8
     steps:
       - checkout
       - attach_workspace:
           at: .
-      - run: NODE_OPTIONS=--max_old_space_size=4096 npm run coverage
-      - run: bash <(curl -s https://codecov.io/bash)
+      - run:
+          name: Create shared coverage outputs folder
+          command: mkdir -p /tmp/coverage
+      - run:
+          name: Coverage
+          command: |
+            TEST_FILES="{$(circleci tests glob "test/contracts/*.js" | \
+              circleci tests split --split-by=timings | xargs | sed -e 's/ /,/g')}"
+            npm run coverage -- --testfiles "$TEST_FILES"
+      - run:
+          name: Save coverage
+          command: |
+            cp coverage.json /tmp/coverage/coverage-$CIRCLE_NODE_INDEX.json
+      - persist_to_workspace:
+          root: /tmp/coverage
+          paths:
+            - coverage-*.json
   job-unit-tests-gas-report:
     working_directory: ~/repo
     docker:
@@ -311,6 +343,10 @@ workflows:
       - job-unit-tests-coverage:
           requires:
             - job-prepare
+      - job-unit-tests-coverage-report:
+          requires:
+            - job-prepare
+            - job-unit-tests-coverage
       - job-unit-tests-gas-report:
           requires:
             - job-prepare

.circleci/src/jobs/job-unit-tests-coverage-report.yml

@@ -0,0 +1,11 @@
+# Measures unit and spec test coverage
+{{> job-header.yml}}
+steps:
+  - checkout
+  - attach_workspace:
+      at: /tmp/coverage
+  - run:
+      name: Upload coverage
+      command: |
+        cp -R /tmp/coverage/coverage-*.json .
+        bash <(curl -s https://codecov.io/bash)

.circleci/src/jobs/job-unit-tests-coverage.yml

@@ -1,9 +1,25 @@
 # Measures unit and spec test coverage
 {{> job-header.yml}}
 resource_class: large
+parallelism: 8
 steps:
   - checkout
   - attach_workspace:
       at: .
-  - run: NODE_OPTIONS=--max_old_space_size=4096 npm run coverage
-  - run: bash <(curl -s https://codecov.io/bash)
+  - run:
+      name: Create shared coverage outputs folder
+      command: mkdir -p /tmp/coverage
+  - run:
+      name: Coverage
+      command: |
+        TEST_FILES="{$(circleci tests glob "test/contracts/*.js" | \
+          circleci tests split --split-by=timings | xargs | sed -e 's/ /,/g')}"
+        npm run coverage -- --testfiles "$TEST_FILES"
+  - run:
+      name: Save coverage
+      command: |
+        cp coverage.json /tmp/coverage/coverage-$CIRCLE_NODE_INDEX.json
+  - persist_to_workspace:
+      root: /tmp/coverage
+      paths:
+        - coverage-*.json

.circleci/src/snippets/require-unit-tests-coverage.yml

@@ -0,0 +1,3 @@
+requires:
+  - job-prepare
+  - job-unit-tests-coverage

.circleci/src/workflows/workflow-all.yml

@@ -17,6 +17,8 @@ jobs:
       {{> require-prepare.yml}}
   - job-unit-tests-coverage:
       {{> require-prepare.yml}}
+  - job-unit-tests-coverage-report:
+      {{> require-unit-tests-coverage.yml}}
   - job-unit-tests-gas-report:
       {{> require-prepare.yml}}
   - job-test-deploy-script: