feat(unstable): Add Deno.Conn.ref()/unref() (#17170)

This commit adds "Deno.Conn.ref()" and "Deno.Conn.unref()" methods.

These methods can be used to make connection block or not block the
event loop from finishing. Refing/unrefing only influences "read" 
operations - ie. scheduling writes to a connection _do_ keep event 
loop alive.

Required for https://github.com/denoland/deno/issues/16710

1 files changed, 49 insertions, 0 deletions

diff --git a/cli/tests/unit/net_test.ts b/cli/tests/unit/net_test.ts
index b4a21578e..930e4f052 100644
--- a/cli/tests/unit/net_test.ts
+++ b/cli/tests/unit/net_test.ts
@@ -906,6 +906,55 @@ Deno.test({
   listener.close();
 });
 
+Deno.test(
+  { permissions: { net: true, read: true, run: true } },
+  async function netConnUnref() {
+    const listener = Deno.listen({ port: 3500 });
+    const intervalId = setInterval(() => {}); // This keeps event loop alive.
+
+    const program = execCode(`
+      async function main() {
+        const conn = await Deno.connect({ port: 3500 });
+        conn.unref();
+        await conn.read(new Uint8Array(10)); // The program exits here
+        throw new Error(); // The program doesn't reach here  
+      }
+      main();
+    `);
+    const conn = await listener.accept();
+    const [statusCode, _output] = await program;
+    conn.close();
+    listener.close();
+    clearInterval(intervalId);
+    assertEquals(statusCode, 0);
+  },
+);
+
+Deno.test(
+  { permissions: { net: true, read: true, run: true } },
+  async function netConnUnrefReadable() {
+    const listener = Deno.listen({ port: 3500 });
+    const intervalId = setInterval(() => {}); // This keeps event loop alive.
+
+    const program = execCode(`
+      async function main() {
+        const conn = await Deno.connect({ port: 3500 });
+        conn.unref();
+        const reader = conn.readable.getReader();
+        await reader.read(); // The program exits here
+        throw new Error(); // The program doesn't reach here  
+      }
+      main();
+    `);
+    const conn = await listener.accept();
+    const [statusCode, _output] = await program;
+    conn.close();
+    listener.close();
+    clearInterval(intervalId);
+    assertEquals(statusCode, 0);
+  },
+);
+
 Deno.test({ permissions: { net: true } }, async function netTcpReuseAddr() {
   const listener1 = Deno.listen({
     hostname: "127.0.0.1",