Add wasm sample for CI (#2372)

* Add wasm sample for CI

* Add wasm sample for CI

* Add wasm sample for CI

samples/wasm/src/lib.rs

@@ -0,0 +1,19 @@
+mod utils;
+
+use wasm_bindgen::prelude::*;
+
+// When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
+// allocator.
+#[cfg(feature = "wee_alloc")]
+#[global_allocator]
+static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
+
+#[wasm_bindgen]
+extern {
+    fn alert(s: &str);
+}
+
+#[wasm_bindgen]
+pub fn greet() {
+    alert("Hello, wasm!");
+}

samples/wasm/src/utils.rs

@@ -0,0 +1,11 @@
+#[allow(unused)]
+pub fn set_panic_hook() {
+    // When the `console_error_panic_hook` feature is enabled, we can call the
+    // `set_panic_hook` function at least once during initialization, and then
+    // we will get better error messages if our code ever panics.
+    //
+    // For more details see
+    // https://github.com/rustwasm/console_error_panic_hook#readme
+    #[cfg(feature = "console_error_panic_hook")]
+    console_error_panic_hook::set_once();
+}