feat: add baseBranch option

.changeset/unlucky-lies-brush.md

@@ -0,0 +1,5 @@
+---
+"@changesets/action": minor
+---
+
+add option 'baseBranch'

README.md

@@ -13,6 +13,7 @@ This action for [Changesets](https://github.com/atlassian/changesets) creates a
 - setupGitUser - Sets up the git user for commits as `"github-actions[bot]"`. Default to `true`
 - createGithubReleases - A boolean value to indicate whether to create Github releases after `publish` or not. Default to `true`
 - cwd - Changes node's `process.cwd()` if the project is not located on the root. Default to `process.cwd()`
+- baseBranch - The branch to create the pull request against. Default to the branch the action is running on.
 
 ### Outputs
 

action.yml

@@ -31,6 +31,9 @@ inputs:
   branch:
     description: Sets the branch in which the action will run. Default to `github.ref_name` if not provided
     required: false
+  baseBranch:
+    description: Sets the base branch for the pull request. Default to the branch the action runs on if not provided
+    required: false
 outputs:
   published:
     description: A boolean value to indicate whether a publishing is happened or not

src/index.ts

@@ -110,6 +110,7 @@ const getOptionalInput = (name: string) => core.getInput(name) || undefined;
         commitMessage: getOptionalInput("commit"),
         hasPublishScript,
         branch: getOptionalInput("branch"),
+        baseBranch: getOptionalInput("baseBranch"),
       });
 
       core.setOutput("pullRequestNumber", String(pullRequestNumber));

src/run.ts

@@ -300,6 +300,7 @@ type VersionOptions = {
   hasPublishScript?: boolean;
   prBodyMaxCharacters?: number;
   branch?: string;
+  baseBranch?: string;
 };
 
 type RunVersionResult = {
@@ -315,11 +316,13 @@ export async function runVersion({
   hasPublishScript = false,
   prBodyMaxCharacters = MAX_CHARACTERS_PER_MESSAGE,
   branch,
+  baseBranch,
 }: VersionOptions): Promise<RunVersionResult> {
   const octokit = setupOctokit(githubToken);
 
   let repo = `${github.context.repo.owner}/${github.context.repo.repo}`;
   branch = branch ?? github.context.ref.replace("refs/heads/", "");
+  baseBranch ??= branch;
   let versionBranch = `changeset-release/${branch}`;
 
   let { preState } = await readChangesetState(cwd);
@@ -396,7 +399,7 @@ export async function runVersion({
   if (existingPullRequests.data.length === 0) {
     core.info("creating pull request");
     const { data: newPullRequest } = await octokit.rest.pulls.create({
-      base: branch,
+      base: baseBranch,
       head: versionBranch,
       title: finalPrTitle,
       body: prBody,