Merge branch '281-new-job-yarn' into 'latest'

## Objective

This job allows you to build your project using a script (`build` by default)

from your `package.json` file.

## How to use it

1. Ensure that your project have

   [`package.json`](https://classic.yarnpkg.com/en/docs/package-json/){:target="_blank"}

   file which contains the script required to build (`build` by default)

1. Add the corresponding URL to your `.gitlab-ci.yml` file (see [Getting

   started](/getting-started)). Example:

    ```yaml

    include:

      - remote: 'https://jobs.r2devops.io/yarn_build.yml'

    ```

1. If you need to customize the job (stage, variables, ...) 👉 check the [jobs

   customization](/use-the-hub/#jobs-customization)

1. Well done, your job is ready to work ! 😀

## Job details

* Job name: `yarn_build`

* Default stage: `build`

* Docker image: [`node:15.7-buster`](https://hub.docker.com/_/node){:target="_blank"}

* When: `always`

### Variables

| Name | Description | Default |

| ---- | ----------- | ------- |

| `PROJECT_ROOT` | Path to the directory containing `package.json` (path relative from the root of the repository) | `.` |

| `YARN_INSTALL_OPTIONS` | Additional options for `yarn install` | ` ` |

| `YARN_BUILD_SCRIPT_NAME` | The build script in the `package.json` that you want to run | `build` |

| `YARN_BUILD_OPTIONS` | Options passed to your build script | ` ` |

| `YARN_BUILD_OUTPUT_FOLDER` | Path to the output produced by the `yarn` build script used (path relative from the `PROJECT_ROOT`) | `build` |

| `PAGES_DEPLOY` | Prepare your build result to be deployed on pages (require [pages job](jobs/deploy/pages/)) | `false` |

| `PAGES_FOLDER` | Path where to copy the output to be exposed for deployment on [pages](jobs/deploy/pages/) (path relative from the root of the repository) | `./website_build` |

### Example to deploy on pages

Following example of `.gitlab-ci.yml` file describes how to enable Gitlab pages

deployment using this job:

```yaml

stages:

  - build

  - deploy

include:

  - remote: 'https://jobs.r2devops.io/yarn_build.yml'

  - remote: 'https://jobs.r2devops.io/pages.yml'

yarn_build:

  variables:

    PAGES_DEPLOY: "true"

```

### Artifact

Result of  build is [exposed

as](https://docs.gitlab.com/ee/ci/yaml/#artifactsexpose_as){:target="_blank"}

`yarn build` in merge requests.

!!! warning

    Exposition of artifact doesn't work currently because of [this issue from

    Gitlab](https://gitlab.com/gitlab-org/gitlab/-/issues/37129){:target="_blank"}. As soon as

    the issue will be fixed, exposed artifacts will be available in merge

    requests.

name: yarn_build

description: A ready to use `yarn` job to build your application

default_stage: build

icon: 🧱

maintainer: coconux

license: MIT

* Initial version

# Job from R2Devops hub --> r2devops.io

stages:

  - build

yarn_build:

  stage: build

  image:

    name: node:15.7-buster

    entrypoint: [""]

  variables:

    PROJECT_ROOT: "."

    YARN_INSTALL_OPTIONS: ""

    YARN_BUILD_SCRIPT_NAME: "build"

    YARN_BUILD_OPTIONS: ""

    YARN_BUILD_OUTPUT_FOLDER: "build"

    PAGES_DEPLOY: "false"

    PAGES_FOLDER: "./website_build"

  script:

    # Working directory

    - cd $PROJECT_ROOT

    - yarn install $YARN_INSTALL_OPTIONS

    - yarn run $YARN_BUILD_SCRIPT_NAME $YARN_BUILD_OPTIONS

    # To deploy on pages

    - if [ "$PAGES_DEPLOY" == "true" ]; then

        # Pages folder must to be at the root of the repo

    -   cd $CI_PROJECT_DIR

    -   cp -r ${PROJECT_ROOT}/${YARN_BUILD_OUTPUT_FOLDER} ${CI_PROJECT_DIR}/${PAGES_FOLDER}

    - fi

  artifacts:

    expose_as: "yarn build"

    paths:

      - "${PROJECT_ROOT}/${YARN_BUILD_OUTPUT_FOLDER}"

      # To deploy on pages

      - "${PAGES_FOLDER}"