fix(runtime): feature-flag snapshot from snapshot (#16843)

4 files changed, 13 insertions, 3 deletions

diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index 0e46fd498..0bbb75ddc 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -26,7 +26,7 @@ harness = false
 path = "./bench/lsp_bench_standalone.rs"
 
 [build-dependencies]
-deno_runtime.workspace = true
+deno_runtime = { workspace = true, features = ["snapshot_from_snapshot"] }
 deno_core.workspace = true
 regex.workspace = true
 serde.workspace = true
diff --git a/runtime/Cargo.toml b/runtime/Cargo.toml
index d130e9edc..ccfebe8af 100644
--- a/runtime/Cargo.toml
+++ b/runtime/Cargo.toml
@@ -12,6 +12,8 @@ description = "Provides the deno runtime library"
 [features]
 # "fake" feature that allows to generate docs on docs.rs
 docsrs = []
+# feature that modifies the snapshot to allow extending it
+snapshot_from_snapshot = []
 
 [lib]
 name = "deno_runtime"
diff --git a/runtime/build.rs b/runtime/build.rs
index 62a3da03b..5887941ca 100644
--- a/runtime/build.rs
+++ b/runtime/build.rs
@@ -169,7 +169,14 @@ mod not_docs {
   }
 
   pub fn build_snapshot(runtime_snapshot_path: PathBuf) {
-    let js_files = get_js_files(env!("CARGO_MANIFEST_DIR"), "js");
+    #[allow(unused_mut)]
+    let mut js_files = get_js_files(env!("CARGO_MANIFEST_DIR"), "js");
+    #[cfg(not(feature = "snapshot_from_snapshot"))]
+    {
+      let manifest = env!("CARGO_MANIFEST_DIR");
+      let path = PathBuf::from(manifest);
+      js_files.push(path.join("js").join("99_main.js"));
+    }
     create_runtime_snapshot(runtime_snapshot_path, js_files);
   }
 }
diff --git a/runtime/web_worker.rs b/runtime/web_worker.rs
index a8e0842f2..89f0bd6c2 100644
--- a/runtime/web_worker.rs
+++ b/runtime/web_worker.rs
@@ -17,6 +17,7 @@ use deno_core::futures::channel::mpsc;
 use deno_core::futures::future::poll_fn;
 use deno_core::futures::stream::StreamExt;
 use deno_core::futures::task::AtomicWaker;
+use deno_core::located_script_name;
 use deno_core::serde::Deserialize;
 use deno_core::serde::Serialize;
 use deno_core::serde_json::json;
@@ -31,8 +32,8 @@ use deno_core::ModuleLoader;
 use deno_core::ModuleSpecifier;
 use deno_core::RuntimeOptions;
 use deno_core::SharedArrayBufferStore;
+use deno_core::Snapshot;
 use deno_core::SourceMapGetter;
-use deno_core::{located_script_name, Snapshot};
 use deno_node::RequireNpmResolver;
 use deno_tls::rustls::RootCertStore;
 use deno_web::create_entangled_message_port;