feat: read the release assets asynchronously (#552)

Previously all assets were being read synchronously into memory, making
the action unsuitable for releasing very large assets. Because the
client library allows stream body inputs (it just forwards it to the
underlying `fetch` implementation), just do it.

The idea is also suggested by @enumag in
#353 (comment).

Fixes: #353

Signed-off-by: WANG Xuerui <git@xen0n.name>

Author: xen0n

__tests__/github.test.ts

@@ -1,6 +1,5 @@
-//import * as assert from "assert";
-//const assert = require('assert');
 import * as assert from "assert";
+import { text } from "stream/consumers";
 import { mimeOrDefault, asset } from "../src/github";
 
 describe("github", () => {
@@ -19,7 +18,7 @@ describe("github", () => {
       assert.equal(name, "bar.txt");
       assert.equal(mime, "text/plain");
       assert.equal(size, 10);
-      assert.equal(data.toString(), "release me");
+      assert.equal(await text(data), "release me");
     });
   });
 });

src/github.ts

@@ -1,6 +1,6 @@
 import { GitHub } from "@actions/github/lib/utils";
 import { Config, isTag, releaseBody, alignAssetName } from "./util";
-import { statSync, readFileSync } from "fs";
+import { createReadStream, statSync, type ReadStream } from "fs";
 import { getType } from "mime";
 import { basename } from "path";
 
@@ -10,7 +10,7 @@ export interface ReleaseAsset {
   name: string;
   mime: string;
   size: number;
-  data: Buffer;
+  data: ReadStream;
 }
 
 export interface Release {
@@ -145,7 +145,7 @@ export const asset = (path: string): ReleaseAsset => {
     name: basename(path),
     mime: mimeOrDefault(path),
     size: statSync(path).size,
-    data: readFileSync(path),
+    data: createReadStream(path, "binary"),
   };
 };