fix: draft prereleases before uploading assets

Signed-off-by: Rui Chen <rui@chenrui.dev>

README.md

@@ -240,6 +240,11 @@ will retain its original info.
 existing draft release, set `draft: true` to keep it draft; if `draft` is omitted,
 the action will publish that draft after uploading assets.
 
+💡 When the action creates a new release that uploads assets, it stages the release
+as a draft first, uploads the assets, and then publishes it unless `draft: true`
+keeps it as a draft. This keeps new prereleases compatible with GitHub immutable
+releases.
+
 💡 `files` is glob-based, so literal filenames that contain glob metacharacters such as
 `[` or `]` must be escaped in the pattern.
 

__tests__/github.test.ts

@@ -517,7 +517,7 @@ describe('github', () => {
       );
     });
 
-    it('creates published prereleases without the forced draft-first path', async () => {
+    it('creates published prereleases without the forced draft-first path when no assets are configured', async () => {
       const prereleaseConfig = {
         ...config,
         input_prerelease: true,
@@ -564,6 +564,54 @@ describe('github', () => {
       );
     });
 
+    it('creates draft prereleases when assets are configured so uploads can finish before publish', async () => {
+      const prereleaseConfig = {
+        ...config,
+        input_prerelease: true,
+        input_draft: false,
+        input_files: ['draft-false.txt'],
+      };
+      const createdRelease: Release = {
+        id: 1,
+        upload_url: 'test',
+        html_url: 'test',
+        tag_name: 'v1.0.0',
+        name: 'test',
+        body: 'test',
+        target_commitish: 'main',
+        draft: true,
+        prerelease: true,
+        assets: [],
+      };
+
+      const createReleaseSpy = vi.fn(async () => ({ data: createdRelease }));
+      const mockReleaser: Releaser = {
+        getReleaseByTag: () => Promise.reject({ status: 404 }),
+        createRelease: createReleaseSpy,
+        updateRelease: () => Promise.reject('Not implemented'),
+        finalizeRelease: () => Promise.reject('Not implemented'),
+        allReleases: async function* () {
+          yield { data: [createdRelease] };
+        },
+        listReleaseAssets: () => Promise.reject('Not implemented'),
+        deleteReleaseAsset: () => Promise.reject('Not implemented'),
+        deleteRelease: () => Promise.reject('Not implemented'),
+        updateReleaseAsset: () => Promise.reject('Not implemented'),
+        uploadReleaseAsset: () => Promise.reject('Not implemented'),
+      } as const;
+
+      const result = await release(prereleaseConfig, mockReleaser, 1);
+
+      assert.equal(result.release.id, createdRelease.id);
+      assert.equal(result.created, true);
+      expect(createReleaseSpy).toHaveBeenCalledWith(
+        expect.objectContaining({
+          draft: true,
+          prerelease: true,
+        }),
+      );
+    });
+
     it('retries upload after deleting conflicting asset on 422 already_exists race', async () => {
       const uploadReleaseAsset = vi
         .fn()

action.yml

@@ -16,7 +16,7 @@ inputs:
     description: "Gives a tag name. Defaults to github.ref_name. refs/tags/<name> values are normalized to <name>."
     required: false
   draft:
-    description: "Keeps the release as a draft. Defaults to false. When reusing an existing draft release, set this to true to keep it draft; omit it to publish after upload."
+    description: "Keeps the release as a draft. Defaults to false. New releases that upload assets are staged as drafts first; set this to true to keep the release draft instead of publishing it after upload."
     required: false
   prerelease:
     description: "Identify the release as a prerelease. Defaults to false"

src/github.ts

@@ -875,7 +875,8 @@ async function createRelease(
   const name = config.input_name || tag;
   const body = releaseBody(config);
   const prerelease = config.input_prerelease;
-  const draft = prerelease === true ? config.input_draft === true : true;
+  const draft =
+    config.input_draft === true || prerelease !== true || (config.input_files?.length ?? 0) > 0;
   const target_commitish = config.input_target_commitish;
   const make_latest = config.input_make_latest;
   let commitMessage: string = '';