Add wasm tests (#74)

src/deadline_support.rs

@@ -0,0 +1,37 @@
+use std::time::Duration;
+
+#[cfg(not(feature = "wasm32_web_time"))]
+pub use std::time::Instant;
+
+/// WASM (browser) specific instant type.
+///
+/// This type is only available when the `wasm32_web_time` feature is enabled.  In that
+/// case this is an alias for [`web_time::Instant`].
+#[cfg(feature = "wasm32_web_time")]
+pub use web_time::Instant;
+
+/// Checks if a deadline was exeeded.
+pub fn deadline_exceeded(deadline: Option<Instant>) -> bool {
+    #[allow(unreachable_code)]
+    match deadline {
+        Some(deadline) => {
+            #[cfg(all(target_arch = "wasm32", not(feature = "wasm32_web_time")))]
+            {
+                return false;
+            }
+            Instant::now() > deadline
+        }
+        None => false,
+    }
+}
+
+/// Converst a duration into a deadline.  This can be a noop on wasm
+#[allow(unused)]
+pub fn duration_to_deadline(add: Duration) -> Option<Instant> {
+    #[allow(unreachable_code)]
+    #[cfg(all(target_arch = "wasm32", not(feature = "wasm32_web_time")))]
+    {
+        return None;
+    }
+    Instant::now().checked_add(add)
+}