[fix] handle promise rejections for {#await} in SSR (#6790)

.github/workflows/ci.yml

@@ -6,7 +6,7 @@ jobs:
     timeout-minutes: 15
     strategy:
       matrix:
-        node-version: [8, 10, 12, 14]
+        node-version: [8, 10, 12, 14, 16]
         os: [ubuntu-latest, windows-latest, macOS-latest]
     steps:
       - uses: actions/checkout@v1

src/compiler/compile/render_ssr/handlers/AwaitBlock.ts

@@ -13,7 +13,10 @@ export default function(node: AwaitBlock, renderer: Renderer, options: RenderOpt
 
 	renderer.add_expression(x`
 		function(__value) {
-			if (@is_promise(__value)) return ${pending};
+			if (@is_promise(__value)) {
+				__value.then(null, @noop);
+				return ${pending};
+			}
 			return (function(${node.then_node ? node.then_node : ''}) { return ${then}; }(__value));
 		}(${node.expression.node})
 	`);

test/hydration/index.ts

@@ -52,6 +52,7 @@ describe('hydration', () => {
 			const cwd = path.resolve(`${__dirname}/samples/${dir}`);
 
 			compileOptions = config.compileOptions || {};
+			compileOptions.accessors = 'accessors' in config ? config.accessors : true;
 
 			const window = env();
 

test/hydration/samples/event-handler/main.svelte

@@ -1,9 +1,9 @@
 <script>
-	let clicked;
+	export let clicked;
 </script>
 
 <button on:click='{() => clicked = true}'>click me</button>
 
 {#if clicked}
 	<p>clicked!</p>
-{/if}
+{/if}

test/runtime/index.ts

@@ -25,12 +25,13 @@ let compile = null;
 const sveltePath = process.cwd().split('\\').join('/');
 
 let unhandled_rejection = false;
-process.on('unhandledRejection', err => {
+function unhandledRejection_handler(err) {
 	unhandled_rejection = err;
-});
+}
 
 describe('runtime', () => {
 	before(() => {
+		process.on('unhandledRejection', unhandledRejection_handler);
 		svelte = loadSvelte(false);
 		svelte$ = loadSvelte(true);
 
@@ -46,6 +47,7 @@ describe('runtime', () => {
 
 		return setupHtmlEqual();
 	});
+	after(() => process.removeListener('unhandledRejection', unhandledRejection_handler));
 
 	const failed = new Set();