Setting up Mocha Test Coverage and Parallelism In Circle CI

.nycrc.yaml

all: true
check-coverage: false
clean: false
lines: 80
statements: 80
branches: 50
functions: 50
reporter:
  - lcov

config.yml

version: 2.1

jobs:
  checkout_source:
    docker:
      - image: circleci/node:14.15.1-stretch
    steps:
      - checkout
      - persist_to_workspace:
          root: .
          paths:
            - .

  install_dependencies:
    docker:
      - image: circleci/node:14.15.1-stretch
    steps:
      - attach_workspace:
          at: .
      - restore_cache:
          keys:
            - dependencies-{{ checksum "package-lock.json" }}
      - run:
          name: Install dependencies
          command: npm install
      - save_cache:
          key: dependencies-{{ checksum "package-lock.json" }}
          paths:
            - node_modules
      - persist_to_workspace:
          root: .
          paths:
            - node_modules/*
  test:
    docker:
      - image: circleci/node:14.15.1-stretch
    parallelism: 8
    steps:
      - attach_workspace:
          at: .
      - run:
          name: Run tests
          command:
            circleci tests glob 'test/**/*.spec.ts' |
            circleci tests split |
            xargs npx nyc --temp-dir=./.nyc_output_temp/$CIRCLE_JOB-$CIRCLE_NODE_INDEX/nyc_output mocha
      - persist_to_workspace:
          root: .
          paths:
            - .nyc_output_temp/*

  test_coverage:
    docker:
      - image: circleci/node:14.15.1-stretch
    steps:
      - attach_workspace:
          at: .
      - run:
          name: Merge coverage output
          command: node merge-nyc-output.js
      - run:
          name: Check code coverage
          command: npx nyc report --reporter=lcov --reporter=text-summary --check-coverage

workflows:
  build_workflow:
    jobs:
      - checkout_source
      - install_dependencies:
          requires:
            - checkout_source
      - test:
          requires:
            - install_dependencies
      - test_coverage:
          requires:
            - test

merge-nyc-output.js

'use strict';

const { spawnSync } = require('child_process');
const path = require('path');
const glob = require('glob');
const makeDir = require('make-dir');
const rimraf = require('rimraf');

process.chdir(__dirname);
rimraf.sync('.nyc_output');
makeDir.sync('.nyc_output');

// Merge coverage data from each executor.
glob.sync('.nyc_output_temp/*/nyc_output').forEach((nycOutput) => {
  console.log(`Merging: ${nycOutput}`);
  const cwd = path.dirname(nycOutput);
  const { status, stderr } = spawnSync(
    'npx nyc',
    [
      'merge',
      'nyc_output',
      path.join(__dirname, '.nyc_output', path.basename(cwd) + '.json'),
    ],
    {
      encoding: 'utf8',
      shell: true,
      cwd,
    },
  );

  if (status !== 0) {
    process.exit(status);
  }
});

Hi, Thank you for your sharing.

I wanna ask something, how about the ci/cd for a mocha test when run after deployment from another repository? Thank you