docker-compose - override default container startup command and volumes example

version: '3'
services:
  test:
    build:
      context: .
      dockerfile: Dockerfile.dev
    volumes:
      - /app/node_modules # will bookmark this folder inside a Docker container
      - .:/app # # mount current directory to /app inside container
    command: ["npm", "run", "test"] # the instruction that overrides the default command