feat(core): allow to specify entry point for snapshotted ES modules (#17771)

This commit adds "ExtensionBuilder::esm_entry_point()" function that
allows to specify which of the extension files should be treated as an
entry point. If the entry point is not provided all modules are loaded 
and evaluated, but if it is provided then only the entry point is explicitly
loaded and evaluated.

Co-authored-by: Leo Kettmeir <crowlkats@toaxl.com>

1 files changed, 34 insertions, 17 deletions

diff --git a/core/runtime.rs b/core/runtime.rs
index d922d0ca5..0127e80e6 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -829,26 +829,39 @@ impl JsRuntime {
 
   /// Initializes JS of provided Extensions in the given realm
   fn init_extension_js(&mut self, realm: &JsRealm) -> Result<(), Error> {
+    fn load_and_evaluate_module(
+      runtime: &mut JsRuntime,
+      file_source: &ExtensionFileSource,
+    ) -> Result<(), Error> {
+      futures::executor::block_on(async {
+        let id = runtime
+          .load_side_module(
+            &ModuleSpecifier::parse(&file_source.specifier)?,
+            None,
+          )
+          .await?;
+        let receiver = runtime.mod_evaluate(id);
+        runtime.run_event_loop(false).await?;
+        receiver.await?
+      })
+      .with_context(|| format!("Couldn't execute '{}'", file_source.specifier))
+    }
+
     // Take extensions to avoid double-borrow
     let extensions = std::mem::take(&mut self.extensions_with_js);
     for ext in &extensions {
       {
         let esm_files = ext.get_esm_sources();
-        for file_source in esm_files {
-          futures::executor::block_on(async {
-            let id = self
-              .load_side_module(
-                &ModuleSpecifier::parse(&file_source.specifier)?,
-                None,
-              )
-              .await?;
-            let receiver = self.mod_evaluate(id);
-            self.run_event_loop(false).await?;
-            receiver.await?
-          })
-          .with_context(|| {
-            format!("Couldn't execute '{}'", file_source.specifier)
-          })?;
+        if let Some(entry_point) = ext.get_esm_entry_point() {
+          let file_source = esm_files
+            .iter()
+            .find(|file| file.specifier == entry_point)
+            .unwrap();
+          load_and_evaluate_module(self, file_source)?;
+        } else {
+          for file_source in esm_files {
+            load_and_evaluate_module(self, file_source)?;
+          }
         }
       }
 
@@ -1770,7 +1783,11 @@ impl JsRuntime {
       .map(|handle| v8::Local::new(tc_scope, handle))
       .expect("ModuleInfo not found");
     let mut status = module.get_status();
-    assert_eq!(status, v8::ModuleStatus::Instantiated);
+    assert_eq!(
+      status,
+      v8::ModuleStatus::Instantiated,
+      "Module not instantiated {id}"
+    );
 
     let (sender, receiver) = oneshot::channel();
 
@@ -4974,7 +4991,7 @@ Deno.core.ops.op_async_serialize_object_with_numbers_as_keys({
         _is_dyn_import: bool,
       ) -> Pin<Box<ModuleSourceFuture>> {
         let source = r#"
-        // This module doesn't really exist, just verifying that we'll get 
+        // This module doesn't really exist, just verifying that we'll get
         // an error when specifier starts with "internal:".
         import { core } from "internal:core.js";
         "#;