fix(runtime): only discard extension sources if a snapshot is provided (#22023)

Fixes #21928.

We have a code path which empties the extension sources because they're
expected to be pre-executed in the snapshot. Instead of using
conditional compilation for that, we now just check if a snapshot was
provided.

Removes the `dont_use_runtime_snapshot` feature. We didn't allow not
providing a snapshot unless this feature was provided, now we always do.

Adds the `only_snapshotted_js_sources` feature for us to use in CLI.
This asserts that a snapshot is provided and gates the runtime
transpilation code so it isn't included in the executable.

1 files changed, 7 insertions, 14 deletions

diff --git a/runtime/web_worker.rs b/runtime/web_worker.rs
index 2b6eb19c9..78674af02 100644
--- a/runtime/web_worker.rs
+++ b/runtime/web_worker.rs
@@ -490,14 +490,16 @@ impl WebWorker {
       ops::web_worker::deno_web_worker::init_ops_and_esm(),
     ];
 
+    #[cfg(__runtime_js_sources)]
+    assert!(cfg!(not(feature = "only_snapshotted_js_sources")), "'__runtime_js_sources' is incompatible with 'only_snapshotted_js_sources'.");
+
     for extension in &mut extensions {
-      #[cfg(not(feature = "__runtime_js_sources"))]
-      {
+      if options.startup_snapshot.is_some() {
         extension.js_files = std::borrow::Cow::Borrowed(&[]);
         extension.esm_files = std::borrow::Cow::Borrowed(&[]);
         extension.esm_entry_point = None;
       }
-      #[cfg(feature = "__runtime_js_sources")]
+      #[cfg(not(feature = "only_snapshotted_js_sources"))]
       {
         use crate::shared::maybe_transpile_source;
         for source in extension.esm_files.to_mut() {
@@ -511,17 +513,8 @@ impl WebWorker {
 
     extensions.extend(std::mem::take(&mut options.extensions));
 
-    #[cfg(all(
-      feature = "include_js_files_for_snapshotting",
-      not(feature = "__runtime_js_sources")
-    ))]
-    options
-      .startup_snapshot
-      .as_ref()
-      .expect("Sources are not embedded and a user snapshot was not provided.");
-
-    #[cfg(not(feature = "dont_use_runtime_snapshot"))]
-    options.startup_snapshot.as_ref().expect("A user snapshot was not provided, if you want to create a runtime without a snapshot use 'dont_use_runtime_snapshot' Cargo feature.");
+    #[cfg(feature = "only_snapshotted_js_sources")]
+    options.startup_snapshot.as_ref().expect("A user snapshot was not provided, even though 'only_snapshotted_js_sources' is used.");
 
     // Hook up the summary metrics if the user or subcommand requested them
     let (op_summary_metrics, op_metrics_factory_fn) =