1 files changed, 76 insertions, 0 deletions
diff --git a/core/runtime.rs b/core/runtime.rs
index bea9908ed..cb8b242e9 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -3052,6 +3052,82 @@ assertEquals(1, notify_return_value);
   }
 
   #[test]
+  fn test_op_detached_buffer() {
+    use serde_v8::DetachedBuffer;
+
+    #[op]
+    fn op_sum_take(b: DetachedBuffer) -> Result<u64, anyhow::Error> {
+      Ok(b.as_ref().iter().clone().map(|x| *x as u64).sum())
+    }
+
+    #[op]
+    fn op_boomerang(
+      b: DetachedBuffer,
+    ) -> Result<DetachedBuffer, anyhow::Error> {
+      Ok(b)
+    }
+
+    let ext = Extension::builder()
+      .ops(vec![op_sum_take::decl(), op_boomerang::decl()])
+      .build();
+
+    let mut runtime = JsRuntime::new(RuntimeOptions {
+      extensions: vec![ext],
+      ..Default::default()
+    });
+
+    runtime
+      .execute_script(
+        "test.js",
+        r#"
+        const a1 = new Uint8Array([1,2,3]);
+        const a1b = a1.subarray(0, 3);
+        const a2 = new Uint8Array([5,10,15]);
+        const a2b = a2.subarray(0, 3);
+        
+        
+        if (!(a1.length > 0 && a1b.length > 0)) {
+          throw new Error("a1 & a1b should have a length");
+        }
+        let sum = Deno.core.opSync('op_sum_take', a1b);
+        if (sum !== 6) {
+          throw new Error(`Bad sum: ${sum}`);
+        }
+        if (a1.length > 0 || a1b.length > 0) {
+          throw new Error("expecting a1 & a1b to be detached");
+        }
+
+        const a3 = Deno.core.opSync('op_boomerang', a2b);
+        if (a3.byteLength != 3) {
+          throw new Error(`Expected a3.byteLength === 3, got ${a3.byteLength}`);
+        }
+        if (a3[0] !== 5 || a3[1] !== 10) {
+          throw new Error(`Invalid a3: ${a3[0]}, ${a3[1]}`);
+        }
+        if (a2.byteLength > 0 || a2b.byteLength > 0) {
+          throw new Error("expecting a2 & a2b to be detached, a3 re-attached");
+        }
+        
+        const wmem = new WebAssembly.Memory({ initial: 1, maximum: 2 });
+        const w32 = new Uint32Array(wmem.buffer);
+        w32[0] = 1; w32[1] = 2; w32[2] = 3;
+        const assertWasmThrow = (() => {
+          try {
+            let sum = Deno.core.opSync('op_sum_take', w32.subarray(0, 2));
+            return false;
+          } catch(e) {
+            return e.message.includes('ExpectedDetachable');
+          }
+        });
+        if (!assertWasmThrow()) {
+          throw new Error("expected wasm mem to not be detachable");
+        }
+      "#,
+      )
+      .unwrap();
+  }
+
+  #[test]
   fn test_op_unstable_disabling() {
     #[op]
     fn op_foo() -> Result<i64, anyhow::Error> {