From 04a78badc58c6b5cdc0f9ad9eb67e2dc91a9e78e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lauren=C8=9Biu=20Nicola?= <lnicola@dend.ro>
Date: Sat, 20 Apr 2019 09:29:03 +0300
Subject: [PATCH] Implement Debug for JsFuture

---
 crates/futures/src/lib.rs     | 7 +++++++
 crates/futures/tests/tests.rs | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/crates/futures/src/lib.rs b/crates/futures/src/lib.rs
index aaab7611..62d5e88d 100644
--- a/crates/futures/src/lib.rs
+++ b/crates/futures/src/lib.rs
@@ -104,6 +104,7 @@
 #![deny(missing_docs)]
 
 use std::cell::{Cell, RefCell};
+use std::fmt;
 use std::rc::Rc;
 use std::sync::Arc;
 
@@ -128,6 +129,12 @@ pub struct JsFuture {
     callbacks: Option<(Closure<FnMut(JsValue)>, Closure<FnMut(JsValue)>)>,
 }
 
+impl fmt::Debug for JsFuture {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "JsFuture {{ ... }}")
+    }
+}
+
 impl From<Promise> for JsFuture {
     fn from(js: Promise) -> JsFuture {
         // Use the `then` method to schedule two callbacks, one for the
diff --git a/crates/futures/tests/tests.rs b/crates/futures/tests/tests.rs
index d8ea2674..2262d7ef 100755
--- a/crates/futures/tests/tests.rs
+++ b/crates/futures/tests/tests.rs
@@ -52,6 +52,13 @@ fn error_future_is_rejected_promise() -> impl Future<Item = (), Error = JsValue>
     })
 }
 
+#[wasm_bindgen_test]
+fn debug_jsfuture() {
+    let p = js_sys::Promise::resolve(&JsValue::from(42));
+    let f = JsFuture::from(p);
+    assert_eq!(&format!("{:?}", f), "JsFuture { ... }");
+}
+
 #[wasm_bindgen]
 extern "C" {
     fn setTimeout(c: &Closure<FnMut()>);