Add select-mode, version, pack and publish sub-actions (#656)

* Add select-mode, version, and publish sub-actions

* Rename

* No github-token needed for select-mode for now

* extend select-mode with publish-plan check and upload

* Rename base-branch to pr-base-branch

* add `pack` subaction

* `--from-pack` support in the publish subaction

* rename CLI arg

* update rolldown config

* rename pack dir input/output

* tweak retendion days

---------

Co-authored-by: Mateusz Burzyński <mateuszburzynski@gmail.com>

src/utils.ts

@@ -1,6 +1,17 @@
 import fs from "node:fs/promises";
+import { createRequire } from "node:module";
+import path from "node:path";
+import artifact from "@actions/artifact";
+import {
+  exec,
+  getExecOutput,
+  type ExecOptions as ActionsExecOptions,
+  type ExecOutput,
+} from "@actions/exec";
 import { getPackages, type Package } from "@manypkg/get-packages";
 
+const require = createRequire(import.meta.url);
+
 export const BumpLevels = {
   dep: 0,
   patch: 1,
@@ -111,3 +122,57 @@ export function fileExists(filePath: string) {
     () => false,
   );
 }
+
+function resolveChangesetsCli(cwd: string) {
+  return require.resolve("@changesets/cli/bin.js", {
+    paths: [cwd],
+  });
+}
+
+interface ExecOptions extends Omit<ActionsExecOptions, "env"> {
+  env?: Record<string, string | undefined>;
+}
+
+export function execChangesetsCli(args: string[], options?: ExecOptions) {
+  return exec(
+    "node",
+    [resolveChangesetsCli(options?.cwd ?? process.cwd()), ...args],
+    options as ActionsExecOptions,
+  );
+}
+
+export function getExecOutputChangesetsCli(
+  args: string[],
+  options?: ExecOptions,
+): Promise<ExecOutput> {
+  return getExecOutput(
+    "node",
+    [resolveChangesetsCli(options?.cwd ?? process.cwd()), ...args],
+    options as ActionsExecOptions,
+  );
+}
+
+export async function downloadArtifact(
+  tmpDir: string,
+  artifactId: number,
+  name: string,
+) {
+  if (!Number.isInteger(artifactId) || artifactId <= 0) {
+    throw new Error(
+      `Invalid ${JSON.stringify(name)} artifact id: ${artifactId}`,
+    );
+  }
+
+  const downloadPath = path.join(tmpDir, `${name}-${artifactId}-${Date.now()}`);
+  const result = await artifact.downloadArtifact(artifactId, {
+    path: downloadPath,
+  });
+
+  if (!result.downloadPath) {
+    throw new Error(
+      `${JSON.stringify(name)} artifact download did not return a path for artifact ${artifactId}`,
+    );
+  }
+
+  return result.downloadPath;
+}