introduce utils for creating a jar archive

src/bin/tools/tee.ts

@@ -0,0 +1,37 @@
+import { PassThrough, Readable } from "stream";
+
+export default function tee(input: Readable) {
+    const a = new PassThrough();
+    const b = new PassThrough();
+
+    let aFull = false;
+    let bFull = false;
+
+    a.on("drain", () => {
+        aFull = false;
+        if (!aFull && !bFull) input.resume();
+    });
+    b.on("drain", () => {
+        bFull = false;
+        if (!aFull && !bFull) input.resume();
+    });
+
+    input.on("error", e => {
+        a.emit("error", e);
+        b.emit("error", e);
+    });
+
+    input.on("data", chunk => {
+        aFull = !a.write(chunk);
+        bFull = !b.write(chunk);
+
+        if (aFull || bFull) input.pause();
+    });
+
+    input.on("end", () => {
+        a.end();
+        b.end();
+    });
+
+    return [a, b] as const;
+}