WIP

Author: Rich-Harris

packages/svelte/src/compiler/phases/3-transform/client/visitors/VariableDeclaration.js

@@ -167,8 +167,19 @@ export function VariableDeclaration(node, context) {
 						declarations.push(
 							b.declarator(
 								declarator.id,
-								b.await(
-									b.call('$.async_derived', rune === '$derived.by' ? value : b.thunk(value, true))
+								b.call(
+									b.member(
+										b.await(
+											b.call(
+												'$.suspend',
+												b.call(
+													'$.async_derived',
+													rune === '$derived.by' ? value : b.thunk(value, true)
+												)
+											)
+										),
+										'exit'
+									)
 								)
 							)
 						);

packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/declarations.js

@@ -17,18 +17,6 @@ export function get_value(node) {
  */
 export function add_state_transformers(context) {
 	for (const [name, binding] of context.state.scope.declarations) {
-		if (
-			binding.kind === 'derived' &&
-			context.state.analysis.async_deriveds.has(/** @type {CallExpression} */ (binding.initial))
-		) {
-			// async deriveds are a special case
-			context.state.transform[name] = {
-				read: b.call
-			};
-
-			continue;
-		}
-
 		if (
 			is_state_source(binding, context.state.analysis) ||
 			binding.kind === 'derived' ||

packages/svelte/src/internal/client/dom/blocks/boundary.js

@@ -244,6 +244,9 @@ export function trigger_async_boundary(effect, trigger) {
 	}
 }
 
+// TODO separate this stuff out — suspending and context preservation should
+// be distinct concepts
+
 /**
  * @template T
  * @param {Promise<T>} promise