fix(core): panic at build time if extension code contains anything other than 7-bit ASCII (#18372)

This will improve diagnostics and catch any non-ASCII extension code
early.

This will use `debug_assert!` rather than `assert!` to avoid runtime
costs, and ensures (in debug_assert mode only) that all extension source
files are ASCII as we load them.

1 files changed, 2 insertions, 2 deletions

diff --git a/core/runtime.rs b/core/runtime.rs
index c5afbda53..787bac972 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -751,7 +751,7 @@ impl JsRuntime {
             realm.execute_script(
               self.v8_isolate(),
               file_source.specifier,
-              file_source.code.load()?,
+              file_source.load()?,
             )?;
           }
         }
@@ -2544,7 +2544,7 @@ impl JsRealm {
     let scope = &mut self.handle_scope(isolate);
 
     let source = Self::string_from_code(scope, &source_code).unwrap();
-    assert!(name.is_ascii());
+    debug_assert!(name.is_ascii());
     let name =
       v8::String::new_external_onebyte_static(scope, name.as_bytes()).unwrap();
     let origin = bindings::script_origin(scope, name);