Native ES modules (#1460)

* Native ES modules

This is a major refactor of internal compiler.

Before: JS and TS both were sent through the typescript compiler where
their imports were parsed and handled. Both compiled to AMD JS and
finally sent to V8

Now: JS is sent directly into V8. TS is sent through the typescript
compiler, but tsc generates ES modules now instead of AMD. This
generated JS is then dumped into V8.

This should much faster for pure JS code. It may improve TS compilation
speed.

In the future this allows us to separate TS out of the runtime heap and
into its own dedicated snapshot. This will result in a smaller runtime
heap, and thus should be faster.

Some tests were unfortunately disabled to ease landing this patch:
1. compiler_tests.ts which I intend to bring back in later commits.
2. Some text_encoding_test.ts tests which made the file invalid utf8.
   See PR for a discussion.
Also worth noting that this is necessary to support WASM

1 files changed, 5 insertions, 19 deletions

diff --git a/src/deno_dir.rs b/src/deno_dir.rs
index d3d67d195..3b35035d6 100644
--- a/src/deno_dir.rs
+++ b/src/deno_dir.rs
@@ -1,4 +1,5 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+use compiler::CodeFetchOutput;
 use dirs;
 use errors;
 use errors::DenoError;
@@ -19,25 +20,6 @@ use std::result::Result;
 use url;
 use url::Url;
 
-#[derive(Debug)]
-pub struct CodeFetchOutput {
-  pub module_name: String,
-  pub filename: String,
-  pub media_type: msg::MediaType,
-  pub source_code: String,
-  pub maybe_output_code: Option<String>,
-  pub maybe_source_map: Option<String>,
-}
-
-impl CodeFetchOutput {
-  pub fn js_source<'a>(&'a self) -> &'a String {
-    match self.maybe_output_code {
-      None => &self.source_code,
-      Some(ref output_code) => output_code,
-    }
-  }
-}
-
 /// Gets corresponding MediaType given extension
 fn extmap(ext: &str) -> msg::MediaType {
   match ext {
@@ -319,6 +301,10 @@ impl DenoDir {
 
     out.source_code = filter_shebang(out.source_code);
 
+    if out.media_type != msg::MediaType::TypeScript {
+      return Ok(out);
+    }
+
     let result =
       self.load_cache(out.filename.as_str(), out.source_code.as_str());
     match result {