Adding host_metadata to Cloudflare Request Data (#348)

* Adding host_metadata to Cloudflare Request Data

* Update incoming_request_cf_properties.rs

Make `host_metadata` method `catch`

* Update cf.rs

---------

Co-authored-by: Kevin Flansburg <kflansburg@cloudflare.com>
Co-authored-by: Kevin Flansburg <kevin.flansburg@gmail.com>

worker-sys/src/types/incoming_request_cf_properties.rs

@@ -61,6 +61,9 @@ extern "C" {
     #[wasm_bindgen(method, catch, getter, js_name=regionCode)]
     pub fn region_code(this: &IncomingRequestCfProperties) -> Result<Option<String>, JsValue>;
 
+    #[wasm_bindgen(method, catch, getter, js_name=hostMetadata)]
+    pub fn host_metadata(this: &IncomingRequestCfProperties) -> Result<JsValue, JsValue>;
+
     #[wasm_bindgen(method, catch, getter)]
     pub fn timezone(this: &IncomingRequestCfProperties) -> Result<String, JsValue>;
 

worker/src/cf.rs

@@ -172,6 +172,18 @@ impl Cf {
     pub fn is_eu_country(&self) -> bool {
         self.inner.is_eu_country().unwrap() == Some("1".to_string())
     }
+
+    pub fn host_metadata<T: serde::de::DeserializeOwned>(&self) -> crate::Result<Option<T>> {
+        let host_metadata = self.inner.host_metadata()?;
+        if host_metadata.is_undefined() {
+            Ok(None)
+        } else {
+            serde_wasm_bindgen::from_value(host_metadata)
+                .map(Some)
+                .map_err(|e| wasm_bindgen::JsValue::from(e.to_string()))
+        }
+        .map_err(crate::Error::from)
+    }
 }
 
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