futures: Add sanity tests for conversion between Promises and Futures

Part of #614

.travis.yml

@@ -62,9 +62,9 @@ matrix:
         - cargo test --target wasm32-unknown-unknown --features serde-serialize
         # Make sure the `std` feature works if disabled
         - cargo test --target wasm32-unknown-unknown -p no-std
-        # Make sure the `wasm-bindgen-futures` tests pass. Right now, this just
-        # verifies that the example program in the crate level docs compiles.
+        # Make sure the `wasm-bindgen-futures` tests pass.
         - cargo test -p wasm-bindgen-futures
+        - cargo test -p wasm-bindgen-futures --target wasm32-unknown-unknown
       addons:
         firefox: latest
       if: branch = master

crates/futures/Cargo.toml

@@ -7,3 +7,6 @@ authors = ["The wasm-bindgen Developers"]
 futures = "0.1.20"
 js-sys = { path = "../js-sys", version = '0.2.0' }
 wasm-bindgen = { path = "../..", version = '0.2.15' }
+
+[target.'cfg(target_arch = "wasm32")'.dev-dependencies]
+wasm-bindgen-test = { path = '../test', version = '0.2.15' }

crates/futures/tests/tests.rs

@@ -0,0 +1,51 @@
+#![feature(use_extern_macros)]
+#![cfg(target_arch = "wasm32")]
+
+extern crate futures;
+extern crate js_sys;
+extern crate wasm_bindgen;
+extern crate wasm_bindgen_futures;
+extern crate wasm_bindgen_test;
+
+use futures::Future;
+use wasm_bindgen::prelude::*;
+use wasm_bindgen_futures::{future_to_promise, JsFuture};
+use wasm_bindgen_test::*;
+
+#[wasm_bindgen_test(async)]
+fn promise_resolve_is_ok_future() -> impl Future<Item = (), Error = JsValue> {
+    let p = js_sys::Promise::resolve(&JsValue::from(42));
+    JsFuture::from(p)
+        .map(|x| {
+            assert_eq!(x, 42);
+        }).map_err(|_| unreachable!())
+}
+
+#[wasm_bindgen_test(async)]
+fn promise_reject_is_error_future() -> impl Future<Item = (), Error = JsValue> {
+    let p = js_sys::Promise::reject(&JsValue::from(42));
+    JsFuture::from(p).map(|_| unreachable!()).or_else(|e| {
+        assert_eq!(e, 42);
+        Ok(())
+    })
+}
+
+#[wasm_bindgen_test(async)]
+fn ok_future_is_resolved_promise() -> impl Future<Item = (), Error = JsValue> {
+    let f = futures::future::ok(JsValue::from(42));
+    let p = future_to_promise(f);
+    JsFuture::from(p)
+        .map(|x| {
+            assert_eq!(x, 42);
+        }).map_err(|_| unreachable!())
+}
+
+#[wasm_bindgen_test(async)]
+fn error_future_is_rejected_promise() -> impl Future<Item = (), Error = JsValue> {
+    let f = futures::future::err(JsValue::from(42));
+    let p = future_to_promise(f);
+    JsFuture::from(p).map(|_| unreachable!()).or_else(|e| {
+        assert_eq!(e, 42);
+        Ok(())
+    })
+}