@kilianpaquier/semantic-release-backmerge

---

A semantic-release plugin to handle backmerge between branches.

Step	Description
verifyConditions	Verify the presence of specific plugin configuration alongside required environment variables
success	Apply backmerge for the appropriate target branches

• How to ?
• How does it work ?
• Usage
• Configuration
  • Templating
  • Maintenance branches
• Environment variables
  • Bitbucket (data center/server)
  • Bitbucket (cloud)
  • Gitea
  • Github
  • Gitlab

How to ?

bun

bun install -D @kilianpaquier/semantic-release-backmerge

npm

npm install -D @kilianpaquier/semantic-release-backmerge

pnpm

pnpm install -D @kilianpaquier/semantic-release-backmerge

yarn

yarn install -D @kilianpaquier/semantic-release-backmerge

How does it work ?

When configured in targets, a provided branch (i.e main) can be backmerged in one or multiple others (i.e. develop) when a released in made with semantic-release.

With the instance of main and develop, develop branch will be check'ed out locally and merged with git merge <branch> --ff -m <commit_message>. It means that if git can avoid a merge commit, it will avoid it.

In the event of conflicts (it may happen, production fixes could be made to main and features developped in develop), a pull request is created from main to develop.

Usage

This plugin can be configured through the semantic-release configuration file.

{
  "branches": ["main"],
  "plugins": [
    "@semantic-release/commit-analyzer",
    "@semantic-release/release-notes-generator",
    "@semantic-release/git",
    "@semantic-release/github",
    [
      "@kilianpaquier/semantic-release-backmerge",
      {
        "commit": "chore(release): merge branch ${ from } into ${ to } [skip ci]",
        "targets": [
          { "from": "main", "to": "develop" }
          { "from": "main", "to": "staging" }
          { "from": "staging", "to": "develop" }
        ],
        "title": "Automatic merge failure",
      }
    ],
    "@semantic-release/exec",
  ]
}

Configuration

name	required	default	description
apiPathPrefix	Yes	Guessed in environment variables. Unless baseUrl is specifically provided.	API Prefix for your platform (i.e. /api/v4 for gitlab).
baseUrl	Yes	Guessed in environment variables	Platform base URL (i.e. https://gitlab.com for gitlab).
checkHasPull	No	true	Whether to check if a pull request already exists between a backmerged branch and the released branch. This check is only made if backmerge with git wasn't successful.
commit	No	chore(release): merge branch ${ from } into ${ to } [skip ci]	Merge commit in case the fast-forward mode couldn't be done.
dryRun	No	--dry-run option from semantic-release	Whether to really push and create pull requests or only log the actions.
platform	Yes	Guessed in environment variables. Unless baseUrl is specifically provided.	Platform name. Either bitbucket, bitbucket-cloud, gitea, github or gitlab.
targets	No	[]	Backmerge targets, a slice / list of { from: <from>, to: <to> }. from and to can be regexp like (develop|staging) or v[0-9]+(.[0-9]+)?, etc.
title	No	Automatic merge failure	Pull request title to set when creating pull requests.

Templating

Configuration commit and title are templated with lodash during backmerge or pull request creation. The following data are available:

name	type	description
from	string	Backmerge source branch.
to	string	Backmerge target branch.
lastRelease	object	Last release with version, gitTag, gitHead, name, and channels fields.
nextRelease	object	Last release with version, gitTag, gitHead, name, type, channel and notes fields.

Maintenance branches

In some cases, you may want to maintain multiple maintenance branches associated to the same major version.

In that case, semantic-release-backmerge is covering for you. When providing a from branch matching a maintenance branch, then backmerge will only allow backmerge into more recent maintenance branches (of the same major version):

• v1 cannot be backmerged
• v1.6 can be backmerged into v1.7 (and above) and v1
• v1.x cannot be backmerged
• v1.5.x can be backmerged into v1.6.x (and above) and v1.x

Environment variables

When working with specifics git platforms, and as such sometimes with associated CI functionalities, environment variable are by default provided.

For semantic-release-backmerge to work flawlessly with your platform, you may provide in the next sections the right environment variables.

To avoid painful configurations, you may use the environments variables to automatically guess baseUrl, apiPathPrefix and platform instead of given them in your configuration file.

Bitbucket (data center/server)

variable name	description
BITBUCKET_URL	Base URL to your Bitbucket server
BB_TOKEN or BITBUCKET_TOKEN	Bitbucket token to push backmerged branches (in case of HTTP(S) connection) or create pull requests

Notes:

• The Base URL name differs from Bitbucket (Cloud) because the API endpoints to create pull request aren't the same.
• When BITBUCKET_URL is provided, you may omit the following configuration variables:
  • baseUrl is given this URL
  • apiPathPrefix is given by default /rest/api/1.0
  • platform is set to bitbucket
• Endpoint to create pull requests is POST {baseUrl}{apiPathPrefix}/projects/{owner}/repos/{name}/pull-requests
  • Example: POST https://stash.company.com/rest/api/1.0/projects/kilianpaquier/repos/semantic-release-backmerge/pull-requests
  • See documentation

Bitbucket (cloud)

variable name	description
BITBUCKET_CLOUD_URL	Base URL to your Bitbucket cloud server
BB_TOKEN or BITBUCKET_TOKEN	Bitbucket token to push backmerged branches (in case of HTTP(S) connection) or create pull requests

Notes:

• The Base URL name differs from Bitbucket (Data Center/Server) because the API endpoints to create pull request aren't the same.
• When BITBUCKET_CLOUD_URL is provided, you may omit the following configuration variables:
  • baseUrl is given this URL
  • apiPathPrefix is given by default /2.0
  • platform is set to bitbucket-cloud
• Endpoint to create pull requests is POST {baseUrl}{apiPathPrefix}/repositories/{owner}/{name}/pullrequests
  • Example: POST https://company.bitbucket.org/2.0/repositories/kilianpaquier/semantic-release-backmerge/pullrequests
  • See documentation

Gitea

variable name	description
GITEA_URL	Base URL to your gitea server
GITEA_TOKEN	Gitea token to push backmerged branches (in case of HTTP(S) connection) or create pull requests

Notes:

• When GITEA_URL is provided, you may omit the following configuration variables:
  • baseUrl is given this URL
  • apiPathPrefix is given by default /api/v1
  • platform is set to gitea
• Endpoint to create pull requests is POST {baseUrl}{apiPathPrefix}/repos/{owner}/{name}/pulls
  • Example: POST https://company.gitea.com/api/v1/repos/kilianpaquier/semantic-release-backmerge/pulls
  • See documentation

Github

variable name	description
GH_URL or GITHUB_URL or GITHUB_API_URL	Base URL to your github server, note that GITHUB_API_URL already exists with GitHub Actions
GH_TOKEN or GITHUB_TOKEN	GitHub token to push backmerged branches (in case of HTTP(S) connection) or create pull requests

Notes:

• When GH_URL or GITHUB_URL or GITHUB_API_URL is provided, you may omit the following configuration variables:
  • baseUrl is given this URL
  • apiPathPrefix is given by default ""
  • platform is set to github
• Endpoint to create pull requests is POST {baseUrl}{apiPathPrefix}/repos/{owner}/{repo}/pulls
  • Example: POST https://api.github.com/repos/kilianpaquier/semantic-release-backmerge/pulls
  • See documentation

Gitlab

variable name	description
GL_URL or GITLAB_URL or CI_SERVER_URL	Base URL to your gitlab server, note that CI_SERVER_URL already exists with GitLab CICD
GL_TOKEN or GITLAB_TOKEN	GitLab token to push backmerged branches (in case of HTTP(S) connection) or create pull requests (api, read_repository and write_repository scopes)

Notes:

• When GL_URL or GITLAB_URL or CI_SERVER_URL is provided, you may omit the following configuration variables:
  • baseUrl is given this URL
  • apiPathPrefix is given by default /api/v4
  • platform is set to gitlab
• Endpoint to create pull requests is POST {baseUrl}{apiPathPrefix}/projects/{uri_encoded({owner}/{repo})}/merge_requests
  • Example: POST https://gitlab.company.com/api/v4/projects/kilianpaquier%2Fsemantic-release-backmerge/merge_requests
  • Example: POST https://gitlab.company.com/api/v4/projects/kilianpaquier%2Fsubgroup%2Fsemantic-release-backmerge/merge_requests
  • See documentation