fix(core): allow esm extensions not included in snapshot (#18980)

Fixes #18979.

This changes the predicate for allowing `ext:` specifier resolution from
`snapshot_loaded_and_not_snapshotting` to `ext_resolution_allowed` which
is only set to true during the extension module loading phase. Module
loaders as used in core
are now declared as `ExtModuleLoader` rather than `dyn ModuleLoader`.

3 files changed, 14 insertions, 49 deletions

diff --git a/runtime/examples/hello_runtime.js b/runtime/examples/hello_runtime.js
index 066fa21d6..5b079d8d8 100644
--- a/runtime/examples/hello_runtime.js
+++ b/runtime/examples/hello_runtime.js
@@ -1,3 +1,4 @@
 // Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
 console.log("Hello world!");
 console.log(Deno);
+Extension.hello();
diff --git a/runtime/examples/hello_runtime.rs b/runtime/examples/hello_runtime.rs
index 2e930a03f..157a200f4 100644
--- a/runtime/examples/hello_runtime.rs
+++ b/runtime/examples/hello_runtime.rs
@@ -1,72 +1,31 @@
 // Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
 
-use deno_core::anyhow::Context;
 use deno_core::error::AnyError;
 use deno_core::FsModuleLoader;
-use deno_runtime::deno_broadcast_channel::InMemoryBroadcastChannel;
-use deno_runtime::deno_web::BlobStore;
 use deno_runtime::permissions::PermissionsContainer;
 use deno_runtime::worker::MainWorker;
 use deno_runtime::worker::WorkerOptions;
-use deno_runtime::BootstrapOptions;
 use std::path::Path;
 use std::rc::Rc;
-use std::sync::Arc;
 
-fn get_error_class_name(e: &AnyError) -> &'static str {
-  deno_runtime::errors::get_error_class_name(e).unwrap_or("Error")
-}
+deno_core::extension!(hello_runtime, esm = ["hello_runtime_bootstrap.js"]);
 
 #[tokio::main]
 async fn main() -> Result<(), AnyError> {
-  let module_loader = Rc::new(FsModuleLoader);
-  let create_web_worker_cb = Arc::new(|_| {
-    todo!("Web workers are not supported in the example");
-  });
-  let web_worker_event_cb = Arc::new(|_| {
-    todo!("Web workers are not supported in the example");
-  });
-
-  let options = WorkerOptions {
-    bootstrap: BootstrapOptions::default(),
-    extensions: vec![],
-    startup_snapshot: None,
-    unsafely_ignore_certificate_errors: None,
-    root_cert_store_provider: None,
-    seed: None,
-    source_map_getter: None,
-    format_js_error_fn: None,
-    web_worker_preload_module_cb: web_worker_event_cb.clone(),
-    web_worker_pre_execute_module_cb: web_worker_event_cb,
-    create_web_worker_cb,
-    maybe_inspector_server: None,
-    should_break_on_first_statement: false,
-    should_wait_for_inspector_session: false,
-    module_loader,
-    node_fs: None,
-    npm_resolver: None,
-    get_error_class_fn: Some(&get_error_class_name),
-    cache_storage_dir: None,
-    origin_storage_dir: None,
-    blob_store: BlobStore::default(),
-    broadcast_channel: InMemoryBroadcastChannel::default(),
-    shared_array_buffer_store: None,
-    compiled_wasm_module_store: None,
-    stdio: Default::default(),
-  };
-
   let js_path =
     Path::new(env!("CARGO_MANIFEST_DIR")).join("examples/hello_runtime.js");
   let main_module = deno_core::resolve_path(
     &js_path.to_string_lossy(),
-    &std::env::current_dir().context("Unable to get CWD")?,
+    &std::env::current_dir()?,
   )?;
-  let permissions = PermissionsContainer::allow_all();
-
   let mut worker = MainWorker::bootstrap_from_options(
     main_module.clone(),
-    permissions,
-    options,
+    PermissionsContainer::allow_all(),
+    WorkerOptions {
+      module_loader: Rc::new(FsModuleLoader),
+      extensions: vec![hello_runtime::init_ops_and_esm()],
+      ..Default::default()
+    },
   );
   worker.execute_main_module(&main_module).await?;
   worker.run_event_loop(false).await?;
diff --git a/runtime/examples/hello_runtime_bootstrap.js b/runtime/examples/hello_runtime_bootstrap.js
new file mode 100644
index 000000000..759dde939
--- /dev/null
+++ b/runtime/examples/hello_runtime_bootstrap.js
@@ -0,0 +1,5 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+function hello() {
+  console.log("Hello from extension!");
+}
+globalThis.Extension = { hello };