Melos Action

Activates Melos for your GitHub workflow. It can also automatically version, dry-run and publish your packages to pub.dev.

NOTE: Remember to check the "Allow GitHub Actions to create and approve pull requests" checkbox in the bottom of the Actions > General section of your repository settings if you want to use create-pr: true.

Installation

The melos-action needs to have either dart or flutter on the path before it can activate melos. With this set up it will automatically add melos to your path and run melos bootstrap, for more advanced usa-cases, like automatic releases, see the Parameters section.

With Flutter

steps:
- uses: actions/checkout@v4
- uses: subosito/flutter-action@v2
- uses: bluefireteam/melos-action@v3

With Dart

steps:
- uses: actions/checkout@v4
- uses: dart-lang/setup-dart@v1
- uses: bluefireteam/melos-action@v3

Parameters

There are a few parameters that can be set to customize the behavior of the action, they are all optional.

Parameter	Default	Description
melos-version	latest	The version of Melos to activate.
run-bootstrap	true	Whether to run melos bootstrap after activating Melos.
enforce-lockfile	false	Whether the versions in the lockfiles should be enforced.
run-versioning	false	Whether packages should be versioned.
run-versioning-prerelease	false	Whether packages should be versioned as a prerelease.
publish-dry-run	false	Whether packages should be dry-run published.
publish	false	Whether packages should be published to pub.dev.
create-pr	false	Whether to create a PR with the changes made by Melos.
git-email	contact@blue-fire.xyz	The email to use when committing changes.
git-name	Melos Action	The name to use when committing changes.

To set a specific parameter you use the with keyword in your action, like in the example below.

steps:
  - uses: actions/checkout@v4
  - uses: subosito/flutter-action@v2
  - uses: bluefireteam/melos-action@v3
    with:
      run-bootstrap: false

Set melos version

You can set a version constraint for the melos version if you don't want the latest version (default).

Simply adding the version, like in the example below, will guarantee that exactly the specified version is activated.

You can also use all range constraints that exist for pub. For example '^1.0.0' would allow any version from 1.0.0 to 2.0.0 (but not including 2.0.0). If you want an even tighter restriction you can define the version like this '>=1.2.0 < 1.3.0' which would allow any version between 1.2.0 (included) to 1.3.0 (excluded).

steps:
- uses: actions/checkout@v4
- uses: subosito/flutter-action@v2
- uses: bluefireteam/melos-action@v3
  with:
    melos-version: '1.2.0'

Automatic versioning and publishing

NOTE: This won't work until dart-lang/pub.dev#7462 is merged.

It is recommended that you read through and follow the set up steps at dart.dev before continuing, not applicable for dry-runs of course.

Remember that if your package isn't already published to pub.dev you need to manually publish it the first time, after that you can use the action to automatically publish it.

If you want to automatically release your packages for example when a new PR is merged you have a few different options:

1. Create two actions, one which versions and dry-run publishes your packages and then creates a release preparation PR every time a PR from a normal user is merged and then a second action that publishes your packages to pub.dev when the release preparation PR is merged.
2. Directly publish your packages to pub.dev when a PR from a normal user is merged and create a PR with the versioning changes afterwards.
3. Only use the action to ensure in your pipeline that your packages are releasable, i.e doesn't fail any dry run.

And this note is worth repeating - Remember to check the "Allow GitHub Actions to create and approve pull requests" checkbox in the bottom of the Actions > General section of your repository settings if you want to use create-pr: true.

1. Version and release on each PR

Create a file with the following content name prepare-release.yaml and place it in .github/workflows/:

name: Prepare release
on:
  push:
    branches: [main]

jobs:
  prepare-release:
    name: Prepare release
    permissions:
      contents: write
      pull-requests: write
    runs-on: ubuntu-latest
    if: "!contains(github.event.head_commit.message, 'chore(release)')"
    steps:
      - uses: actions/checkout@v4
      - uses: subosito/flutter-action@v2
      - uses: bluefireteam/melos-action@v3
        with:
          run-versioning: true
          publish-dry-run: true
          create-pr: true

Create a second file with the following content named publish.yaml and place it in .github/workflows/:

name: Publish packages
on:
  push:
    branches: [main]

jobs:
 publish-packages:
   name: Publish packages
   permissions:
     contents: write
     id-token: write # Required for authentication using OIDC
   runs-on: [ ubuntu-latest ]
   if: contains(github.event.head_commit.message, 'chore(release)')
   steps:
     - uses: actions/checkout@v3
     - uses: subosito/flutter-action@v2
     - uses: bluefireteam/melos-action@v3
       with:
         publish: true

2. Directly publish to pub.dev after each PR is merged

Create a second file with the following content named publish.yaml and place it in .github/workflows/:

name: Publish packages
on:
  push:
    branches: [main]

jobs:
 publish-packages:
   name: Publish packages
   permissions:
     contents: write
     id-token: write # Required for authentication using OIDC
   runs-on: [ ubuntu-latest ]
   steps:
     - uses: actions/checkout@v4
     - uses: subosito/flutter-action@v2
     - uses: bluefireteam/melos-action@v3
       with:
         run-versioning: true
         publish-dry-run: true
         publish: true
         create-pr: true

3. Only run dry-run versioning and publishing as a check

Create a second file with the following content named verify-releasable.yaml and place it in .github/workflows/:

name: Verify that the packages are releasable.
on:
  push:
    branches: [main]
  pull_request:

jobs:
 publish-packages:
   name: Verify packages
   runs-on: [ ubuntu-latest ]
   steps:
     - uses: actions/checkout@v4
     - uses: subosito/flutter-action@v2
     - uses: bluefireteam/melos-action@v3
       with:
         run-versioning: true
         publish-dry-run: true

See the examples directory to get files that you can copy and paste into your repository.