1 files changed, 27 insertions, 0 deletions
diff --git a/cli/tests/unit/tls_test.ts b/cli/tests/unit/tls_test.ts
index cf335de49..860965e49 100644
--- a/cli/tests/unit/tls_test.ts
+++ b/cli/tests/unit/tls_test.ts
@@ -148,6 +148,33 @@ Deno.test(
 );
 
 Deno.test(
+  { permissions: { net: true } },
+  async function startTlsWithoutExclusiveAccessToTcpConn() {
+    const hostname = "localhost";
+    const port = getPort();
+
+    const tcpListener = Deno.listen({ hostname, port });
+    const [serverConn, clientConn] = await Promise.all([
+      tcpListener.accept(),
+      Deno.connect({ hostname, port }),
+    ]);
+
+    const buf = new Uint8Array(128);
+    const readPromise = clientConn.read(buf);
+    // `clientConn` is being used by a pending promise (`readPromise`) so
+    // `Deno.startTls` cannot consume the connection.
+    await assertRejects(
+      () => Deno.startTls(clientConn, { hostname }),
+      Deno.errors.BadResource,
+    );
+
+    serverConn.close();
+    tcpListener.close();
+    await readPromise;
+  },
+);
+
+Deno.test(
   { permissions: { read: true, net: true } },
   async function dialAndListenTLS() {
     const resolvable = deferred();