5 files changed, 51 insertions, 1 deletions

diff --git a/cli/factory.rs b/cli/factory.rs
index 14f448b19..e4f9b60fe 100644
--- a/cli/factory.rs
+++ b/cli/factory.rs
@@ -47,6 +47,7 @@ use crate::worker::CliMainWorkerOptions;
 
 use deno_core::error::AnyError;
 use deno_core::parking_lot::Mutex;
+use deno_core::FeatureChecker;
 
 use deno_graph::GraphKind;
 use deno_runtime::deno_fs;
@@ -161,6 +162,7 @@ struct CliFactoryServices {
   type_checker: Deferred<Arc<TypeChecker>>,
   cjs_resolutions: Deferred<Arc<CjsResolutionStore>>,
   cli_node_resolver: Deferred<Arc<CliNodeResolver>>,
+  feature_checker: Deferred<Arc<FeatureChecker>>,
 }
 
 pub struct CliFactory {
@@ -558,6 +560,21 @@ impl CliFactory {
       .await
   }
 
+  pub fn feature_checker(&self) -> &Arc<FeatureChecker> {
+    self.services.feature_checker.get_or_init(|| {
+      let mut checker = FeatureChecker::default();
+      checker.set_exit_cb(Box::new(crate::unstable_exit_cb));
+      // TODO(bartlomieju): enable, once we deprecate `--unstable` in favor
+      // of granular --unstable-* flags.
+      // feature_checker.set_warn_cb(Box::new(crate::unstable_warn_cb));
+      if self.options.unstable() {
+        checker.enable_legacy_unstable();
+      }
+
+      Arc::new(checker)
+    })
+  }
+
   pub async fn create_compile_binary_writer(
     &self,
   ) -> Result<DenoCompileBinaryWriter, AnyError> {
@@ -602,6 +619,7 @@ impl CliFactory {
       self.fs().clone(),
       self.maybe_inspector_server().clone(),
       self.maybe_lockfile().clone(),
+      self.feature_checker().clone(),
       self.create_cli_main_worker_options()?,
     ))
   }
diff --git a/cli/main.rs b/cli/main.rs
index 1ccd694ee..0817c0984 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -256,6 +256,19 @@ fn unwrap_or_exit<T>(result: Result<T, AnyError>) -> T {
   }
 }
 
+pub(crate) fn unstable_exit_cb(_feature: &str, api_name: &str) {
+  // TODO(bartlomieju): change to "The `--unstable-{feature}` flag must be provided.".
+  eprintln!("Unstable API '{api_name}'. The --unstable flag must be provided.");
+  std::process::exit(70);
+}
+
+#[allow(dead_code)]
+pub(crate) fn unstable_warn_cb(feature: &str) {
+  eprintln!(
+    "The `--unstable` flag is deprecated, use --unstable-{feature} instead."
+  );
+}
+
 pub fn main() {
   setup_panic_hook();
 
diff --git a/cli/standalone/mod.rs b/cli/standalone/mod.rs
index e537f9e0c..612ae9eed 100644
--- a/cli/standalone/mod.rs
+++ b/cli/standalone/mod.rs
@@ -35,6 +35,7 @@ use deno_core::error::type_error;
 use deno_core::error::AnyError;
 use deno_core::futures::FutureExt;
 use deno_core::v8_set_flags;
+use deno_core::FeatureChecker;
 use deno_core::ModuleLoader;
 use deno_core::ModuleSpecifier;
 use deno_core::ModuleType;
@@ -424,6 +425,17 @@ pub async fn run(
 
     PermissionsContainer::new(Permissions::from_options(&permissions)?)
   };
+  let feature_checker = Arc::new({
+    let mut checker = FeatureChecker::default();
+    checker.set_exit_cb(Box::new(crate::unstable_exit_cb));
+    // TODO(bartlomieju): enable, once we deprecate `--unstable` in favor
+    // of granular --unstable-* flags.
+    // feature_checker.set_warn_cb(Box::new(crate::unstable_warn_cb));
+    if metadata.unstable {
+      checker.enable_legacy_unstable();
+    }
+    checker
+  });
   let worker_factory = CliMainWorkerFactory::new(
     StorageKeyResolver::empty(),
     npm_resolver,
@@ -434,6 +446,7 @@ pub async fn run(
     fs,
     None,
     None,
+    feature_checker,
     CliMainWorkerOptions {
       argv: metadata.argv,
       log_level: WorkerLogLevel::Info,
diff --git a/cli/tsc/mod.rs b/cli/tsc/mod.rs
index 5f4f7ddf1..524719755 100644
--- a/cli/tsc/mod.rs
+++ b/cli/tsc/mod.rs
@@ -948,7 +948,7 @@ mod tests {
         .context("Unable to get CWD")
         .unwrap(),
     );
-    let mut op_state = OpState::new(1);
+    let mut op_state = OpState::new(1, None);
     op_state.put(state);
     op_state
   }
diff --git a/cli/worker.rs b/cli/worker.rs
index de8cb2018..d8738d492 100644
--- a/cli/worker.rs
+++ b/cli/worker.rs
@@ -16,6 +16,7 @@ use deno_core::url::Url;
 use deno_core::v8;
 use deno_core::CompiledWasmModuleStore;
 use deno_core::Extension;
+use deno_core::FeatureChecker;
 use deno_core::ModuleId;
 use deno_core::ModuleLoader;
 use deno_core::SharedArrayBufferStore;
@@ -109,6 +110,7 @@ struct SharedWorkerState {
   fs: Arc<dyn deno_fs::FileSystem>,
   maybe_inspector_server: Option<Arc<InspectorServer>>,
   maybe_lockfile: Option<Arc<Mutex<Lockfile>>>,
+  feature_checker: Arc<FeatureChecker>,
 }
 
 impl SharedWorkerState {
@@ -313,6 +315,7 @@ impl CliMainWorkerFactory {
     fs: Arc<dyn deno_fs::FileSystem>,
     maybe_inspector_server: Option<Arc<InspectorServer>>,
     maybe_lockfile: Option<Arc<Mutex<Lockfile>>>,
+    feature_checker: Arc<FeatureChecker>,
     options: CliMainWorkerOptions,
   ) -> Self {
     Self {
@@ -330,6 +333,7 @@ impl CliMainWorkerFactory {
         fs,
         maybe_inspector_server,
         maybe_lockfile,
+        feature_checker,
       }),
     }
   }
@@ -510,6 +514,7 @@ impl CliMainWorkerFactory {
         shared.compiled_wasm_module_store.clone(),
       ),
       stdio,
+      feature_checker: shared.feature_checker.clone(),
     };
 
     let worker = MainWorker::bootstrap_from_options(
@@ -681,6 +686,7 @@ fn create_web_worker_callback(
       ),
       stdio: stdio.clone(),
       cache_storage_dir,
+      feature_checker: shared.feature_checker.clone(),
     };
 
     WebWorker::bootstrap_from_options(