core: introduce extensions (#9800)

Extensions allow declarative extensions to "JsRuntime" (ops, state, JS or middleware).

This allows for:
- `op_crates` to be plug-and-play & self-contained, reducing complexity leaked to consumers
- op middleware (like metrics_op) to be opt-in and for new middleware (unstable, tracing,...)
- `MainWorker` and `WebWorker` to be composable, allowing users to extend workers with their ops whilst benefiting from the other infrastructure (inspector, etc...)

In short extensions improve deno's modularity, reducing complexity and leaky abstractions for embedders and the internal codebase.

1 files changed, 4 insertions, 7 deletions

diff --git a/op_crates/webidl/lib.rs b/op_crates/webidl/lib.rs
index 7e617c7a7..a1a404dbd 100644
--- a/op_crates/webidl/lib.rs
+++ b/op_crates/webidl/lib.rs
@@ -1,14 +1,11 @@
 // Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
 
-use deno_core::JsRuntime;
+use deno_core::Extension;
 
 /// Load and execute the javascript code.
-pub fn init(isolate: &mut JsRuntime) {
-  let files = vec![(
+pub fn init() -> Extension {
+  Extension::pure_js(vec![(
     "deno:op_crates/webidl/00_webidl.js",
     include_str!("00_webidl.js"),
-  )];
-  for (url, source_code) in files {
-    isolate.execute(url, source_code).unwrap();
-  }
+  )])
 }