Check HTTP Method after mapRequestToAsset

Closes #151

packages/kv-asset-handler/src/index.ts

@@ -93,11 +93,6 @@ const getAssetFromKV = async (event: FetchEvent, options?: Partial<Options>): Pr
     throw new InternalError(`there is no KV namespace bound to the script`)
   }
 
-  const SUPPORTED_METHODS = ['GET', 'HEAD']
-  if (!SUPPORTED_METHODS.includes(request.method)) {
-    throw new MethodNotAllowedError(`${request.method} is not a valid request method`)
-  }
-
   const rawPathKey = new URL(request.url).pathname.replace(/^\/+/, '') // strip any preceding /'s
   let pathIsEncoded = false
   let requestKey
@@ -121,6 +116,11 @@ const getAssetFromKV = async (event: FetchEvent, options?: Partial<Options>): Pr
     }
   }
 
+  const SUPPORTED_METHODS = ['GET', 'HEAD']
+  if (!SUPPORTED_METHODS.includes(requestKey.method)) {
+    throw new MethodNotAllowedError(`${requestKey.method} is not a valid request method`)
+  }
+
   const parsedUrl = new URL(requestKey.url)
   const pathname = pathIsEncoded ? decodeURIComponent(parsedUrl.pathname) : parsedUrl.pathname // decode percentage encoded path only when necessary