Add license banner to generated files

package.json

@@ -11,6 +11,7 @@
         "@rollup/plugin-node-resolve": "^16.0.1",
         "@rollup/plugin-sucrase": "5.0.2",
         "@rollup/plugin-terser": "0.4.4",
+        "rollup-plugin-license": "^3.6.0",
         "@types/bun": "1.2.21",
         "@types/deno": "2.3.0",
         "@types/node": "24.3.0",

rollup.config.js

@@ -3,11 +3,30 @@ import nodeResolve from "@rollup/plugin-node-resolve";
 import sucrase from "@rollup/plugin-sucrase";
 import terser from "@rollup/plugin-terser";
 import { createHash } from "node:crypto";
+import { Buffer } from "node:buffer";
+import  license from 'rollup-plugin-license';
+
+const LICENSE_BANNER =
+    "SPDX-License-Identifier: Unlicense\n" +
+    "This file was automatically generated by https://github.com/yt-dlp/ejs on <%= moment().toISOString() %>" +
+    "<% if (dependencies && dependencies.length) { %>" +
+    "\n\nBundled Dependencies:" +
+    "<% _.forEach(dependencies, function (dependency) { if (!dependency.private) { %>" +
+      "\n\n---\nName: <%= dependency.name %>" +
+      "<% if (dependency.version) { %>\nVersion: <%= dependency.version %><% } %>" +
+      "\nLicense: <%= dependency.license %>" +
+      "<% if (dependency.repository && dependency.repository.url) { %>\nRepository: <%= dependency.repository.url %><% } %>" +
+      "<% if (dependency.homepage && dependency.homepage.url) { %>\nHomepage:  <%= dependency.homepage.url %><% } %>" +
+      "<% if (dependency.author) { %>\nAuthor: <%= dependency.author.text() %><% } %>" +
+      "<% if (dependency.licenseText) { %>\n\n<%= dependency.licenseText %><% } %>" +
+      "\n---<% } }) %>\n<% } %>"
+
+const ALLOWED_COMMENTS_RE = /SPDX-License-Identifier:/
 
 function printHash() {
   return {
     name: "hash-output-plugin",
-    async writeBundle(options, bundle) {
+    writeBundle(_options, bundle) {
       for (const [fileName, assetInfo] of Object.entries(bundle)) {
           if (assetInfo.code) {
             try {
@@ -43,6 +62,11 @@ export default defineConfig([
         exclude: ["node_modules/**"],
         transforms: ["typescript"],
       }),
+      license({
+        banner: {
+          content: LICENSE_BANNER
+        },
+      }),
       printHash(),
     ],
   },
@@ -67,7 +91,16 @@ export default defineConfig([
         exclude: ["node_modules/**"],
         transforms: ["typescript"],
       }),
-      terser(),
+      terser({
+        format: {
+          comments: ALLOWED_COMMENTS_RE
+        }
+      }),
+      license({
+        banner: {
+          content: LICENSE_BANNER
+        },
+      }),
       printHash(),
     ],
   },
@@ -85,6 +118,11 @@ export default defineConfig([
         exclude: ["node_modules/**"],
         transforms: ["typescript"],
       }),
+      license({
+        banner: {
+          content: LICENSE_BANNER
+        },
+      }),
       printHash(),
     ],
   },
@@ -103,7 +141,16 @@ export default defineConfig([
         exclude: ["node_modules/**"],
         transforms: ["typescript"],
       }),
-      terser(),
+      terser({
+        format: {
+          comments: ALLOWED_COMMENTS_RE
+        }
+      }),
+      license({
+        banner: {
+          content: LICENSE_BANNER
+        },
+      }),
       printHash(),
     ],
   },