feat: Deprecate "import assertions" with a warning (#24743)

This commit deprecates "import assertions" proposal that has been
replaced with "import attributes".

Any time an import assertion is encountered a warning will be printed
to the terminal. This warning will be printed for both local and 
remote files (ie. user code and dependencies).

Import assertions support will be removed in Deno 2.

cli/cache/code_cache.rs

@@ -80,6 +80,10 @@ impl CodeCache {
       data,
     ));
   }
+
+  pub fn remove_code_cache(&self, specifier: &str) {
+    Self::ensure_ok(self.inner.remove_code_cache(specifier))
+  }
 }
 
 impl code_cache::CodeCache for CodeCache {
@@ -158,6 +162,15 @@ impl CodeCacheInner {
     self.conn.execute(sql, params)?;
     Ok(())
   }
+
+  pub fn remove_code_cache(&self, specifier: &str) -> Result<(), AnyError> {
+    let sql = "
+      DELETE FROM codecache
+      WHERE specifier=$1;";
+    let params = params![specifier];
+    self.conn.execute(sql, params)?;
+    Ok(())
+  }
 }
 
 fn serialize_code_cache_type(

cli/main.rs

@@ -438,11 +438,15 @@ fn resolve_flags_and_init(
     DenoSubcommand::Lsp => vec!["--max-old-space-size=3072".to_string()],
     _ => {
       if *DENO_FUTURE {
+        // TODO(bartlomieju): I think this can be removed as it's handled by `deno_core`
+        // and its settings.
         // deno_ast removes TypeScript `assert` keywords, so this flag only affects JavaScript
         // TODO(petamoriken): Need to check TypeScript `assert` keywords in deno_ast
         vec!["--no-harmony-import-assertions".to_string()]
       } else {
         vec![
+          // TODO(bartlomieju): I think this can be removed as it's handled by `deno_core`
+          // and its settings.
           // If we're still in v1.X version we want to support import assertions.
           // V8 12.6 unshipped the support by default, so force it by passing a
           // flag.
@@ -455,6 +459,7 @@ fn resolve_flags_and_init(
   };
 
   init_v8_flags(&default_v8_flags, &flags.v8_flags, get_v8_flags_from_env());
+  // TODO(bartlomieju): remove last argument in Deno 2.
   deno_core::JsRuntime::init_platform(None, !*DENO_FUTURE);
   util::logger::init(flags.log_level);
 

cli/module_loader.rs

@@ -2,6 +2,7 @@
 
 use std::borrow::Cow;
 use std::cell::RefCell;
+use std::collections::HashSet;
 use std::path::PathBuf;
 use std::pin::Pin;
 use std::rc::Rc;
@@ -44,6 +45,7 @@ use deno_core::error::generic_error;
 use deno_core::error::AnyError;
 use deno_core::futures::future::FutureExt;
 use deno_core::futures::Future;
+use deno_core::parking_lot::Mutex;
 use deno_core::resolve_url;
 use deno_core::ModuleCodeString;
 use deno_core::ModuleLoader;
@@ -291,6 +293,7 @@ impl CliModuleLoaderFactory {
       emitter: self.shared.emitter.clone(),
       parsed_source_cache: self.shared.parsed_source_cache.clone(),
       shared: self.shared.clone(),
+      prevent_v8_code_cache: Default::default(),
     })));
     ModuleLoaderAndSourceMapGetter {
       module_loader: loader,
@@ -342,6 +345,10 @@ struct CliModuleLoaderInner<TGraphContainer: ModuleGraphContainer> {
   emitter: Arc<Emitter>,
   parsed_source_cache: Arc<ParsedSourceCache>,
   graph_container: TGraphContainer,
+  // NOTE(bartlomieju): this is temporary, for deprecated import assertions.
+  // Should be removed in Deno 2.
+  // Modules stored here should not be V8 code-cached.
+  prevent_v8_code_cache: Arc<Mutex<HashSet<String>>>,
 }
 
 impl<TGraphContainer: ModuleGraphContainer>
@@ -827,6 +834,14 @@ impl<TGraphContainer: ModuleGraphContainer> ModuleLoader
     code_cache: &[u8],
   ) -> Pin<Box<dyn Future<Output = ()>>> {
     if let Some(cache) = self.0.shared.code_cache.as_ref() {
+      if self
+        .0
+        .prevent_v8_code_cache
+        .lock()
+        .contains(specifier.as_str())
+      {
+        return std::future::ready(()).boxed_local();
+      }
       // This log line is also used by tests.
       log::debug!(
         "Updating V8 code cache for ES module: {specifier}, [{source_hash:?}]"
@@ -841,6 +856,19 @@ impl<TGraphContainer: ModuleGraphContainer> ModuleLoader
     std::future::ready(()).boxed_local()
   }
 
+  fn purge_and_prevent_code_cache(&self, specifier: &str) {
+    if let Some(cache) = self.0.shared.code_cache.as_ref() {
+      // This log line is also used by tests.
+      log::debug!("Remove V8 code cache for ES module: {specifier}");
+      cache.remove_code_cache(specifier);
+      self
+        .0
+        .prevent_v8_code_cache
+        .lock()
+        .insert(specifier.to_string());
+    }
+  }
+
   fn get_source_map(&self, file_name: &str) -> Option<Vec<u8>> {
     let specifier = resolve_url(file_name).ok()?;
     match specifier.scheme() {

cli/standalone/mod.rs

@@ -745,6 +745,7 @@ pub async fn run(
 
   // Initialize v8 once from the main thread.
   v8_set_flags(construct_v8_flags(&[], &metadata.v8_flags, vec![]));
+  // TODO(bartlomieju): remove last argument in Deno 2.
   deno_core::JsRuntime::init_platform(None, true);
 
   let mut worker = worker_factory

runtime/shared.rs

@@ -116,3 +116,26 @@ pub fn maybe_transpile_source(
 
   Ok((source_text.into(), maybe_source_map))
 }
+
+pub fn import_assertion_callback(
+  args: deno_core::ImportAssertionsSupportCustomCallbackArgs,
+) {
+  let mut msg = deno_terminal::colors::yellow("⚠️  Import assertions are deprecated. Use `with` keyword, instead of 'assert' keyword.").to_string();
+  if let Some(specifier) = args.maybe_specifier {
+    if let Some(source_line) = args.maybe_source_line {
+      msg.push_str("\n\n");
+      msg.push_str(&source_line);
+      msg.push_str("\n\n");
+    }
+    msg.push_str(&format!(
+      "  at {}:{}:{}\n",
+      specifier,
+      args.maybe_line_number.unwrap(),
+      args.column_number
+    ));
+    #[allow(clippy::print_stderr)]
+    {
+      eprintln!("{}", msg);
+    }
+  }
+}

runtime/web_worker.rs

@@ -538,6 +538,13 @@ impl WebWorker {
       options.bootstrap.enable_op_summary_metrics,
       options.strace_ops,
     );
+    let import_assertions_support = if options.bootstrap.future {
+      deno_core::ImportAssertionsSupport::Error
+    } else {
+      deno_core::ImportAssertionsSupport::CustomCallback(Box::new(
+        crate::shared::import_assertion_callback,
+      ))
+    };
 
     let mut js_runtime = JsRuntime::new(RuntimeOptions {
       module_loader: Some(options.module_loader.clone()),
@@ -558,6 +565,7 @@ impl WebWorker {
       validate_import_attributes_cb: Some(Box::new(
         validate_import_attributes_callback,
       )),
+      import_assertions_support,
       ..Default::default()
     });
 

runtime/worker.rs

@@ -476,6 +476,14 @@ impl MainWorker {
       }
     });
 
+    let import_assertions_support = if options.bootstrap.future {
+      deno_core::ImportAssertionsSupport::Error
+    } else {
+      deno_core::ImportAssertionsSupport::CustomCallback(Box::new(
+        crate::shared::import_assertion_callback,
+      ))
+    };
+
     let mut js_runtime = JsRuntime::new(RuntimeOptions {
       module_loader: Some(options.module_loader.clone()),
       startup_snapshot: options.startup_snapshot,
@@ -501,6 +509,7 @@ impl MainWorker {
       validate_import_attributes_cb: Some(Box::new(
         validate_import_attributes_callback,
       )),
+      import_assertions_support,
       eval_context_code_cache_cbs: options.v8_code_cache.map(|cache| {
         let cache_clone = cache.clone();
         (
@@ -544,17 +553,6 @@ impl MainWorker {
     if let Some(op_summary_metrics) = op_summary_metrics {
       js_runtime.op_state().borrow_mut().put(op_summary_metrics);
     }
-    extern "C" fn message_handler(
-      _msg: v8::Local<v8::Message>,
-      _exception: v8::Local<v8::Value>,
-    ) {
-      // TODO(@littledivy): Propogate message to users.
-    }
-
-    // Register message listener
-    js_runtime
-      .v8_isolate()
-      .add_message_listener(message_handler);
 
     if let Some(server) = options.maybe_inspector_server.clone() {
       server.register_inspector(

tests/specs/future/import_assertions/__test__.jsonc

@@ -1,5 +1,14 @@
 {
   "steps": [
+    {
+      "args": "run main.js",
+      "output": "error.out",
+      "exitCode": 1,
+      "envs": {
+        "DENO_FUTURE": "1"
+      }
+    },
+    // Running the same multiple times, should warn each time.
     {
       "args": "run main.js",
       "output": "error.out",

tests/specs/future/import_assertions/success.out

@@ -1 +1,7 @@
+⚠️  Import assertions are deprecated. Use `with` keyword, instead of 'assert' keyword.
+
+import foo from "./main.json" assert { type: "json" };
+
+  at [WILDCARD]import_assertions/main.js:1:30
+
 { foo: "foo" }