1 files changed, 23 insertions, 7 deletions
diff --git a/src/http.rs b/src/http.rs
index 5f78cf232..9ef9adb8f 100644
--- a/src/http.rs
+++ b/src/http.rs
@@ -1,10 +1,12 @@
 // Copyright 2018 the Deno authors. All rights reserved. MIT license.
 
-use errors::DenoResult;
+use errors;
+use errors::{DenoError, DenoResult};
 use tokio_util;
 
-use futures::Future;
-use futures::Stream;
+use futures;
+use futures::future::Either;
+use futures::{Future, Stream};
 use hyper;
 use hyper::client::Client;
 use hyper::client::HttpConnector;
@@ -31,11 +33,25 @@ pub fn get_client() -> Client<Connector, hyper::Body> {
 pub fn fetch_sync_string(module_name: &str) -> DenoResult<String> {
   let url = module_name.parse::<Uri>().unwrap();
   let client = get_client();
-  let future = client
+  let fetch_future = client
     .get(url)
-    .and_then(|response| response.into_body().concat2());
-  let body = tokio_util::block_on(future)?;
-  Ok(String::from_utf8(body.to_vec()).unwrap())
+    .map_err(|err| DenoError::from(err))
+    .and_then(|response| {
+      if !response.status().is_success() {
+        return Either::A(futures::future::err(errors::new(
+          errors::ErrorKind::NotFound,
+          "module not found".to_string(),
+        )));
+      }
+      Either::B(
+        response
+          .into_body()
+          .concat2()
+          .map(|body| String::from_utf8(body.to_vec()).unwrap())
+          .map_err(|err| DenoError::from(err)),
+      )
+    });
+  tokio_util::block_on(fetch_future)
 }
 
 /* TODO(ry) Re-enabled this test. Disabling to work around bug in #782.