guide: Add JsValue example to supported types section

examples/guide-supported-types-examples/js_value.js

@@ -0,0 +1,10 @@
+import {
+  take_js_value_by_value,
+  take_js_value_by_shared_ref,
+  return_js_value,
+} from './guide_supported_types_examples';
+
+take_js_value_by_value(42);
+take_js_value_by_shared_ref('hello');
+
+let v = return_js_value();

examples/guide-supported-types-examples/src/js_value.rs

@@ -0,0 +1,12 @@
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+pub fn take_js_value_by_value(x: JsValue) {}
+
+#[wasm_bindgen]
+pub fn take_js_value_by_shared_ref(x: &JsValue) {}
+
+#[wasm_bindgen]
+pub fn return_js_value() -> JsValue {
+    JsValue::NULL
+}

examples/guide-supported-types-examples/src/lib.rs

@@ -9,3 +9,4 @@ pub mod str;
 pub mod string;
 pub mod char;
 pub mod bool;
+pub mod js_value;

guide/src/reference/types.md

@@ -125,7 +125,19 @@ garbage-collected heap and the Wasm linear memory with `TextDecoder` and
 
 | `T` parameter | `&T` parameter | `&mut T` parameter | `T` return value | `Option<T>` parameter | `Option<T>` return value | JavaScript representation |
 |:---:|:---:|:---:|:---:|:---:|:---:|:---:|
-| Yes | Yes | Yes | Yes | No | No | Any JavaScript value |
+| Yes | Yes | No | Yes | No | No | Any JavaScript value |
+
+### Example Rust Usage
+
+```rust
+{{#include ../../../examples/guide-supported-types-examples/src/js_value.rs}}
+```
+
+### Example JavaScript Usage
+
+```js
+{{#include ../../../examples/guide-supported-types-examples/js_value.js}}
+```
 
 ## `Box<[JsValue]>`