feat: new body option for custom PR body, with placeholders

.changeset/afraid-otters-go.md

@@ -0,0 +1,5 @@
+---
+"@changesets/action": minor
+---
+
+Added `body` option for custom PR body with default placeholders

README.md

@@ -10,6 +10,7 @@ This action for [Changesets](https://github.com/changesets/changesets) creates a
 - version - The command to update version, edit CHANGELOG, read and delete changesets. Default to `changeset version` if not provided
 - commit - The commit message to use. Default to `Version Packages`
 - title - The pull request title. Default to `Version Packages`
+- body - The pull request body. Default to the current implementation. Available placeholders: `<!-- header -->`, `<!-- prestate -->`, `<!-- releasesHeading -->`, `<!-- body -->`
 - 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`
 - commitMode - Specifies the commit mode. Use `"git-cli"` to push changes using the Git CLI, or `"github-api"` to push changes via the GitHub API. When using `"github-api"`, all commits and tags are GPG-signed and attributed to the user or app who owns the `GITHUB_TOKEN`. Default to `git-cli`.

action.yml

@@ -20,6 +20,9 @@ inputs:
   title:
     description: The pull request title. Default to `Version Packages`
     required: false
+  body:
+    description: The pull request body. Default to the current implementation. Available placeholders: `<!-- header -->`, `<!-- prestate -->`, `<!-- releasesHeading -->`, `<!-- body -->`
+    required: false
   setupGitUser:
     description: Sets up the git user for commits as `"github-actions[bot]"`. Default to `true`
     required: false

src/index.ts

@@ -123,6 +123,7 @@ const getOptionalInput = (name: string) => core.getInput(name) || undefined;
         git,
         octokit,
         prTitle: getOptionalInput("title"),
+        prBody: getOptionalInput("body"),
         commitMessage: getOptionalInput("commit"),
         hasPublishScript,
         branch: getOptionalInput("branch"),

src/run.test.ts

@@ -6,7 +6,7 @@ import path from "node:path";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { Git } from "./git.ts";
 import { setupOctokit } from "./octokit.ts";
-import { runVersion } from "./run.ts";
+import { runVersion, getVersionPrBody } from "./run.ts";
 
 vi.mock("@actions/github", () => ({
   context: {
@@ -273,3 +273,105 @@ fluminis divesque vulnere aquis parce lapsis rabie si visa fulmineis.
     );
   });
 });
+
+describe("getVersionPrBody", () => {
+  // Sample data for testing
+  const mockChangedPackagesInfo = [
+    {
+      highestLevel: 1,
+      private: false,
+      content: "### Minor Changes\n\n- Added awesome feature",
+      header: "## test-package@1.1.0"
+    }
+  ];
+
+  it("uses default behavior when prBody is undefined", async () => {
+    const result = await getVersionPrBody({
+      hasPublishScript: false,
+      preState: undefined,
+      changedPackagesInfo: mockChangedPackagesInfo,
+      prBodyMaxCharacters: 10000,
+      prBody: undefined,
+      branch: "main"
+    });
+
+    expect(result).toContain("This PR was opened by the [Changesets release]");
+    expect(result).toContain("# Releases");
+    expect(result).toContain("## test-package@1.1.0");
+    expect(result).toContain("### Minor Changes");
+    expect(result).toContain("- Added awesome feature");
+    // Should not contain placeholder comments when using default behavior
+    expect(result).not.toContain("<!-- header -->");
+    expect(result).not.toContain("<!-- body -->");
+  });
+
+  it("replaces placeholders when prBody contains only placeholders", async () => {
+    const customPrBody = "<!-- header -->\n\n<!-- prestate -->\n\n<!-- releasesHeading -->\n\n<!-- body -->";
+
+    const result = await getVersionPrBody({
+      hasPublishScript: true,
+      preState: undefined,
+      changedPackagesInfo: mockChangedPackagesInfo,
+      prBodyMaxCharacters: 10000,
+      prBody: customPrBody,
+      branch: "main"
+    });
+
+    expect(result).toContain("This PR was opened by the [Changesets release]");
+    expect(result).toContain("the packages will be published to npm automatically");
+    expect(result).toContain("# Releases");
+    expect(result).toContain("## test-package@1.1.0");
+    expect(result).toContain("### Minor Changes");
+    expect(result).toContain("- Added awesome feature");
+    // Should not contain placeholder comments after replacement
+    expect(result).not.toContain("<!-- header -->");
+    expect(result).not.toContain("<!-- body -->");
+  });
+
+  it("uses custom text around placeholders", async () => {
+    const customPrBody = `🚀 **Custom Release PR** 🚀
+
+<!-- header -->
+
+⚠️ **Important Notes:**
+This is a custom PR body with additional context.
+
+<!-- prestate -->
+
+📦 **Package Updates:**
+<!-- releasesHeading -->
+
+<!-- body -->
+
+✅ **Ready to merge when you are!**
+Please review the changes above before merging.`;
+
+    const result = await getVersionPrBody({
+      hasPublishScript: false,
+      preState: undefined,
+      changedPackagesInfo: mockChangedPackagesInfo,
+      prBodyMaxCharacters: 10000,
+      prBody: customPrBody,
+      branch: "develop"
+    });
+
+    // Should contain custom text
+    expect(result).toContain("🚀 **Custom Release PR** 🚀");
+    expect(result).toContain("⚠️ **Important Notes:**");
+    expect(result).toContain("This is a custom PR body with additional context.");
+    expect(result).toContain("📦 **Package Updates:**");
+    expect(result).toContain("✅ **Ready to merge when you are!**");
+    expect(result).toContain("Please review the changes above before merging.");
+
+    // Should still contain replaced content
+    expect(result).toContain("This PR was opened by the [Changesets release]");
+    expect(result).toContain("publish to npm yourself");
+    expect(result).toContain("# Releases");
+    expect(result).toContain("## test-package@1.1.0");
+    expect(result).toContain("### Minor Changes");
+
+    // Should not contain placeholder comments after replacement
+    expect(result).not.toContain("<!-- header -->");
+    expect(result).not.toContain("<!-- body -->");
+  });
+});

src/run.ts

@@ -188,6 +188,7 @@ type GetMessageOptions = {
     header: string;
   }[];
   prBodyMaxCharacters: number;
+  prBody?: string;
   preState?: PreState;
 };
 
@@ -196,6 +197,7 @@ export async function getVersionPrBody({
   preState,
   changedPackagesInfo,
   prBodyMaxCharacters,
+  prBody,
   branch,
 }: GetMessageOptions) {
   let messageHeader = `This PR was opened by the [Changesets release](https://github.com/changesets/action) GitHub action. When you're ready to do a release, you can merge this and ${
@@ -214,34 +216,42 @@ export async function getVersionPrBody({
     : "";
   let messageReleasesHeading = `# Releases`;
 
-  let fullMessage = [
-    messageHeader,
-    messagePrestate,
-    messageReleasesHeading,
+  function useOrBuildTemplate(lines: string[]) {
+    if (!prBody) {
+      return [
+        messageHeader,
+        messagePrestate,
+        messageReleasesHeading,
+        ...lines,
+      ].join('\n');
+    }
+
+    return prBody
+      .replace('<!-- header -->', messageHeader)
+      .replace('<!-- prestate -->', messagePrestate)
+      .replace('<!-- releasesHeading -->', messageReleasesHeading)
+      .replace('<!-- body -->', lines.join('\n'));
+  }
+
+  let fullMessage = useOrBuildTemplate([
     ...changedPackagesInfo.map((info) => `${info.header}\n\n${info.content}`),
-  ].join("\n");
+  ]);
 
   // Check that the message does not exceed the size limit.
   // If not, omit the changelog entries of each package.
   if (fullMessage.length > prBodyMaxCharacters) {
-    fullMessage = [
-      messageHeader,
-      messagePrestate,
-      messageReleasesHeading,
+    fullMessage = useOrBuildTemplate([
       `\n> The changelog information of each package has been omitted from this message, as the content exceeds the size limit.\n`,
       ...changedPackagesInfo.map((info) => `${info.header}\n\n`),
-    ].join("\n");
+    ]);
   }
 
   // Check (again) that the message is within the size limit.
   // If not, omit all release content this time.
   if (fullMessage.length > prBodyMaxCharacters) {
-    fullMessage = [
-      messageHeader,
-      messagePrestate,
-      messageReleasesHeading,
+    fullMessage = useOrBuildTemplate([
       `\n> All release information have been omitted from this message, as the content exceeds the size limit.`,
-    ].join("\n");
+    ]);
   }
 
   return fullMessage;
@@ -253,6 +263,7 @@ type VersionOptions = {
   octokit: Octokit;
   cwd?: string;
   prTitle?: string;
+  prBody?: string;
   commitMessage?: string;
   hasPublishScript?: boolean;
   prBodyMaxCharacters?: number;
@@ -269,6 +280,7 @@ export async function runVersion({
   octokit,
   cwd = process.cwd(),
   prTitle = "Version Packages",
+  prBody,
   commitMessage = "Version Packages",
   hasPublishScript = false,
   prBodyMaxCharacters = MAX_CHARACTERS_PER_MESSAGE,
@@ -348,12 +360,13 @@ export async function runVersion({
     .filter((x) => x)
     .sort(sortTheThings);
 
-  let prBody = await getVersionPrBody({
+  prBody = await getVersionPrBody({
     hasPublishScript,
     preState,
     branch,
     changedPackagesInfo,
     prBodyMaxCharacters,
+    prBody,
   });
 
   if (existingPullRequests.data.length === 0) {