chore: add rollup typescript example to validate definitions

examples/rollup-typescript/rollup.config.js

@@ -0,0 +1,83 @@
+import svelte from "rollup-plugin-svelte";
+import resolve from "@rollup/plugin-node-resolve";
+import commonjs from "@rollup/plugin-commonjs";
+import livereload from "rollup-plugin-livereload";
+import { terser } from "rollup-plugin-terser";
+import sveltePreprocess from "svelte-preprocess";
+import typescript from "@rollup/plugin-typescript";
+
+const production = !process.env.ROLLUP_WATCH;
+
+function serve() {
+  let server;
+
+  function toExit() {
+    if (server) server.kill(0);
+  }
+
+  return {
+    writeBundle() {
+      if (server) return;
+      server = require("child_process").spawn(
+        "npm",
+        ["run", "start", "--", "--dev"],
+        {
+          stdio: ["ignore", "inherit", "inherit"],
+          shell: true,
+        }
+      );
+
+      process.on("SIGTERM", toExit);
+      process.on("exit", toExit);
+    },
+  };
+}
+
+export default {
+  input: "src/main.ts",
+  output: {
+    sourcemap: true,
+    format: "iife",
+    name: "app",
+    file: "public/build/bundle.js",
+  },
+  plugins: [
+    svelte({
+      // enable run-time checks when not in production
+      dev: !production,
+      // we'll extract any component CSS out into
+      // a separate file - better for performance
+      css: (css) => {
+        css.write("public/build/bundle.css");
+      },
+      preprocess: sveltePreprocess(),
+    }),
+
+    // If you have external dependencies installed from
+    // npm, you'll most likely need these plugins. In
+    // some cases you'll need additional configuration -
+    // consult the documentation for details:
+    // https://github.com/rollup/plugins/tree/master/packages/commonjs
+    resolve({
+      browser: true,
+      dedupe: ["svelte"],
+    }),
+    commonjs(),
+    typescript({ sourceMap: !production }),
+
+    // In dev mode, call `npm run start` once
+    // the bundle has been generated
+    !production && serve(),
+
+    // Watch the `public` directory and refresh the
+    // browser on changes when not in production
+    !production && livereload("public"),
+
+    // If we're building for production (npm run build
+    // instead of npm run dev), minify
+    production && terser(),
+  ],
+  watch: {
+    clearScreen: false,
+  },
+};