gistfile1.txt

      steps:
        - restore_cache:
            keys:
              - gatsby-build-v1-{{ .Branch }}-
        - run:
            environment:
              DATA_SOURCE_URL: << parameters.data-source-url >>
            name: Gatsby Build (incremental)
            # yarn or npm uses the same scripts section at package.json 
            # we are safe to use this command as main execution 
            command: |
              if [[ << parameters.incremental-build >> ]];then
                GATSBY_EXPERIMENTAL_PAGE_BUILD_ON_DATA_CHANGES=true npm run-script build --log-pages
              else
                npm run-script build --log-pages
              fi
        - save_cache:
            key: gatsby-build-v1-{{ .Branch }}-{{ epoch }}
            paths:
              - ./public
              - ./.cache