Add fetch_remote_source_async (#1972)

cli/deno_dir.rs

@@ -8,9 +8,10 @@ use crate::fs as deno_fs;
 use crate::http_util;
 use crate::js_errors::SourceMapGetter;
 use crate::msg;
+use crate::tokio_util;
 use crate::version;
-
 use dirs;
+use futures::Future;
 use ring;
 use std;
 use std::fmt::Write;
@@ -492,20 +493,22 @@ fn filter_shebang(bytes: Vec<u8>) -> Vec<u8> {
   }
 }
 
-// Prototype https://github.com/denoland/deno/blob/golang/deno_dir.go#L37-L73
-/// Fetch remote source code.
-fn fetch_remote_source(
+/// Asynchronously fetch remote source file specified by the URL `module_name`
+/// and write it to disk at `filename`.
+fn fetch_remote_source_async(
   module_name: &str,
   filename: &str,
-) -> DenoResult<Option<ModuleMetaData>> {
-  let p = Path::new(&filename);
+) -> impl Future<Item = Option<ModuleMetaData>, Error = DenoError> {
+  let filename = filename.to_string();
+  let module_name = module_name.to_string();
+  let p = PathBuf::from(filename.clone());
   // We write a special ".mime" file into the `.deno/deps` directory along side the
   // cached file, containing just the media type.
   let media_type_filename = [&filename, ".mime"].concat();
-  let mt = Path::new(&media_type_filename);
+  let mt = PathBuf::from(&media_type_filename);
   eprint!("Downloading {}...", &module_name); // no newline
-  let maybe_source = http_util::fetch_sync_string(&module_name);
-  if let Ok((source, content_type)) = maybe_source {
+  http_util::fetch_string(&module_name).and_then(
+    move |(source, content_type)| {
       eprintln!(""); // next line
       match p.parent() {
         Some(ref parent) => fs::create_dir_all(parent),
@@ -527,7 +530,7 @@ fn fetch_remote_source(
       {
         deno_fs::write_file(&mt, content_type.as_bytes(), 0o666)?
       }
-    return Ok(Some(ModuleMetaData {
+      Ok(Some(ModuleMetaData {
         module_name: module_name.to_string(),
         filename: filename.to_string(),
         media_type: map_content_type(&p, Some(&content_type)),
@@ -536,11 +539,18 @@ fn fetch_remote_source(
         maybe_output_code: None,
         maybe_source_map_filename: None,
         maybe_source_map: None,
-    }));
-  } else {
-    eprintln!(" NOT FOUND");
+      }))
+    },
+  )
 }
-  Ok(None)
+
+// Prototype https://github.com/denoland/deno/blob/golang/deno_dir.go#L37-L73
+/// Fetch remote source code.
+fn fetch_remote_source(
+  module_name: &str,
+  filename: &str,
+) -> DenoResult<Option<ModuleMetaData>> {
+  tokio_util::block_on(fetch_remote_source_async(module_name, filename))
 }
 
 /// Fetch local or cached source code.
@@ -582,7 +592,6 @@ fn fetch_local_source(
 #[cfg(test)]
 mod tests {
   use super::*;
-  use crate::tokio_util;
   use tempfile::TempDir;
 
   fn test_setup(reload: bool, recompile: bool) -> (TempDir, DenoDir) {
@@ -816,6 +825,44 @@ mod tests {
     });
   }
 
+  #[test]
+  fn test_fetch_source_async_1() {
+    use crate::tokio_util;
+    // http_util::fetch_sync_string requires tokio
+    tokio_util::init(|| {
+      let (_temp_dir, deno_dir) = test_setup(false, false);
+      let module_name =
+        "http://127.0.0.1:4545/tests/subdir/mt_video_mp2t.t3.ts".to_string();
+      let filename = deno_fs::normalize_path(
+        deno_dir
+          .deps_http
+          .join("127.0.0.1_PORT4545/tests/subdir/mt_video_mp2t.t3.ts")
+          .as_ref(),
+      );
+      let mime_file_name = format!("{}.mime", &filename);
+
+      let result = tokio_util::block_on(fetch_remote_source_async(
+        &module_name,
+        &filename,
+      ));
+      assert!(result.is_ok());
+      let r = result.unwrap().unwrap();
+      assert_eq!(r.source_code, b"export const loaded = true;\n");
+      assert_eq!(&(r.media_type), &msg::MediaType::TypeScript);
+      // matching ext, no .mime file created
+      assert!(fs::read_to_string(&mime_file_name).is_err());
+
+      // Modify .mime, make sure read from local
+      let _ = fs::write(&mime_file_name, "text/javascript");
+      let result2 = fetch_local_source(&module_name, &filename);
+      assert!(result2.is_ok());
+      let r2 = result2.unwrap().unwrap();
+      assert_eq!(r2.source_code, b"export const loaded = true;\n");
+      // Not MediaType::TypeScript due to .mime modification
+      assert_eq!(&(r2.media_type), &msg::MediaType::JavaScript);
+    });
+  }
+
   #[test]
   fn test_fetch_source_1() {
     use crate::tokio_util;

cli/http_util.rs

@@ -1,8 +1,6 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 use crate::errors;
 use crate::errors::DenoError;
-use crate::errors::DenoResult;
-use crate::tokio_util;
 use futures::future::{loop_fn, Loop};
 use futures::{future, Future, Stream};
 use hyper;
@@ -53,6 +51,11 @@ fn resolve_uri_from_location(base_uri: &Uri, location: &str) -> Uri {
   }
 }
 
+#[cfg(test)]
+use crate::errors::DenoResult;
+#[cfg(test)]
+use crate::tokio_util;
+#[cfg(test)]
 /// Synchronously fetchs the given HTTP URL. Returns (content, media_type).
 pub fn fetch_sync_string(module_name: &str) -> DenoResult<(String, String)> {
   tokio_util::block_on(fetch_string(module_name))