8 files changed, 39 insertions, 41 deletions
diff --git a/cli/args/flags.rs b/cli/args/flags.rs
index d1f6c153d..d7d51b374 100644
--- a/cli/args/flags.rs
+++ b/cli/args/flags.rs
@@ -844,45 +844,11 @@ pub fn flags_from_vec(args: Vec<String>) -> clap::error::Result<Flags> {
   if matches.get_flag("unstable") {
     flags.unstable = true;
   }
-  if matches.get_flag("unstable-broadcast-channel") {
-    flags.unstable_features.push(
-      deno_runtime::deno_broadcast_channel::UNSTABLE_FEATURE_NAME.to_string(),
-    );
-  }
-  if matches.get_flag("unstable-ffi") {
-    flags
-      .unstable_features
-      .push(deno_runtime::deno_ffi::UNSTABLE_FEATURE_NAME.to_string());
-  }
-  if matches.get_flag("unstable-fs") {
-    flags
-      .unstable_features
-      .push(deno_runtime::deno_fs::UNSTABLE_FEATURE_NAME.to_string());
-  }
-  if matches.get_flag("unstable-http") {
-    flags
-      .unstable_features
-      .push(deno_runtime::ops::http::UNSTABLE_FEATURE_NAME.to_string());
-  }
-  if matches.get_flag("unstable-kv") {
-    flags
-      .unstable_features
-      .push(deno_runtime::deno_kv::UNSTABLE_FEATURE_NAME.to_string());
-  }
-  if matches.get_flag("unstable-net") {
-    flags
-      .unstable_features
-      .push(deno_runtime::deno_net::UNSTABLE_FEATURE_NAME.to_string());
-  }
-  if matches.get_flag("unstable-worker-options") {
-    flags
-      .unstable_features
-      .push(deno_runtime::ops::worker_host::UNSTABLE_FEATURE_NAME.to_string());
-  }
-  if matches.get_flag("unstable-cron") {
-    flags
-      .unstable_features
-      .push(deno_runtime::deno_cron::UNSTABLE_FEATURE_NAME.to_string());
+
+  for (name, _, _) in crate::UNSTABLE_GRANULAR_FLAGS {
+    if matches.get_flag(&format!("unstable-{}", name)) {
+      flags.unstable_features.push(name.to_string());
+    }
   }
 
   flags.unstable_bare_node_builtins =
diff --git a/cli/main.rs b/cli/main.rs
index 1fa4ee851..94b59b9d6 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -310,6 +310,11 @@ pub(crate) static UNSTABLE_GRANULAR_FLAGS: &[(
     "Enable unstable Deno.cron API",
     8,
   ),
+  (
+    "unsafe-proto",
+    "Enable unsafe __proto__ support. This is a security risk.",
+    9,
+  ),
 ];
 
 pub(crate) fn unstable_exit_cb(_feature: &str, api_name: &str) {
diff --git a/cli/tests/integration/run_tests.rs b/cli/tests/integration/run_tests.rs
index 0ddedbdfb..4ac18cd50 100644
--- a/cli/tests/integration/run_tests.rs
+++ b/cli/tests/integration/run_tests.rs
@@ -4716,3 +4716,17 @@ itest!(workspaces_nested_member {
   http_server: true,
   exit_code: 1,
 });
+
+itest!(unsafe_proto {
+  args: "run -A run/unsafe_proto/main.js",
+  output: "run/unsafe_proto/main.out",
+  http_server: false,
+  exit_code: 0,
+});
+
+itest!(unsafe_proto_flag {
+  args: "run -A --unstable-unsafe-proto run/unsafe_proto/main.js",
+  output: "run/unsafe_proto/main_with_unsafe_proto_flag.out",
+  http_server: false,
+  exit_code: 0,
+});
diff --git a/cli/tests/testdata/run/unsafe_proto/main.js b/cli/tests/testdata/run/unsafe_proto/main.js
new file mode 100644
index 000000000..eb95c55a0
--- /dev/null
+++ b/cli/tests/testdata/run/unsafe_proto/main.js
@@ -0,0 +1,5 @@
+console.log(Object.hasOwn(Object.prototype, "__proto__"));
+
+new Worker(import.meta.resolve("./worker.js"), {
+  type: "module",
+});
diff --git a/cli/tests/testdata/run/unsafe_proto/main.out b/cli/tests/testdata/run/unsafe_proto/main.out
new file mode 100644
index 000000000..4b095fd0f
--- /dev/null
+++ b/cli/tests/testdata/run/unsafe_proto/main.out
@@ -0,0 +1,2 @@
+false
+false
diff --git a/cli/tests/testdata/run/unsafe_proto/main_with_unsafe_proto_flag.out b/cli/tests/testdata/run/unsafe_proto/main_with_unsafe_proto_flag.out
new file mode 100644
index 000000000..bb101b641
--- /dev/null
+++ b/cli/tests/testdata/run/unsafe_proto/main_with_unsafe_proto_flag.out
@@ -0,0 +1,2 @@
+true
+true
diff --git a/cli/tests/testdata/run/unsafe_proto/worker.js b/cli/tests/testdata/run/unsafe_proto/worker.js
new file mode 100644
index 000000000..b22bc8713
--- /dev/null
+++ b/cli/tests/testdata/run/unsafe_proto/worker.js
@@ -0,0 +1,2 @@
+console.log(Object.hasOwn(Object.prototype, "__proto__"));
+close();
diff --git a/cli/worker.rs b/cli/worker.rs
index 361aad2ec..5be64e117 100644
--- a/cli/worker.rs
+++ b/cli/worker.rs
@@ -570,7 +570,8 @@ impl CliMainWorkerFactory {
     // TODO(bartlomieju): this is cruft, update FeatureChecker to spit out
     // list of enabled features.
     let feature_checker = shared.feature_checker.clone();
-    let mut unstable_features = Vec::with_capacity(8);
+    let mut unstable_features =
+      Vec::with_capacity(crate::UNSTABLE_GRANULAR_FLAGS.len());
     for (feature_name, _, id) in crate::UNSTABLE_GRANULAR_FLAGS {
       if feature_checker.check(feature_name) {
         unstable_features.push(*id);
@@ -768,7 +769,8 @@ fn create_web_worker_callback(
     // TODO(bartlomieju): this is cruft, update FeatureChecker to spit out
     // list of enabled features.
     let feature_checker = shared.feature_checker.clone();
-    let mut unstable_features = Vec::with_capacity(8);
+    let mut unstable_features =
+      Vec::with_capacity(crate::UNSTABLE_GRANULAR_FLAGS.len());
     for (feature_name, _, id) in crate::UNSTABLE_GRANULAR_FLAGS {
       if feature_checker.check(feature_name) {
         unstable_features.push(*id);