chore: improve code generation for bind:this in SSR mode (#10524)

* chore: improve code generation for `bind:this` in SSR mode

* test

---------

Co-authored-by: Rich Harris <[email protected]>

Author: Rich-Harris

.changeset/brave-points-sleep.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+chore: improve code generation for `bind:this` in SSR mode

packages/svelte/src/compiler/phases/2-analyze/index.js

@@ -1060,7 +1060,9 @@ const common_visitors = {
 				parent.type === 'SvelteComponent' ||
 				parent.type === 'SvelteSelf'
 			) {
-				context.state.analysis.uses_component_bindings = true;
+				if (node.name !== 'this') {
+					context.state.analysis.uses_component_bindings = true;
+				}
 				break;
 			} else if (is_element_node(parent)) {
 				break;

packages/svelte/src/compiler/phases/3-transform/server/transform-server.js

@@ -853,7 +853,7 @@ function serialize_inline_component(node, component_name, context) {
 
 			const value = serialize_attribute_value(attribute.value, context, false, true);
 			push_prop(b.prop('init', b.key(attribute.name), value));
-		} else if (attribute.type === 'BindDirective') {
+		} else if (attribute.type === 'BindDirective' && attribute.name !== 'this') {
 			// TODO this needs to turn the whole thing into a while loop because the binding could be mutated eagerly in the child
 			push_prop(
 				b.get(attribute.name, [

packages/svelte/tests/snapshot/samples/bind-this/_config.js

@@ -0,0 +1,3 @@
+import { test } from '../../test';
+
+export default test({});

packages/svelte/tests/snapshot/samples/bind-this/_expected/client/index.svelte.js

@@ -0,0 +1,17 @@
+// index.svelte (Svelte VERSION)
+// Note: compiler output will change before 5.0 is released!
+import "svelte/internal/disclose-version";
+import * as $ from "svelte/internal";
+
+export default function Bind_this($$anchor, $$props) {
+	$.push($$props, false);
+	$.init();
+
+	/* Init */
+	var fragment = $.comment($$anchor);
+	var node = $.child_frag(fragment);
+
+	$.bind_this(Foo(node, {}), ($$value) => foo = $$value, foo);
+	$.close_frag($$anchor, fragment);
+	$.pop();
+}

packages/svelte/tests/snapshot/samples/bind-this/_expected/server/index.svelte.js

@@ -0,0 +1,14 @@
+// index.svelte (Svelte VERSION)
+// Note: compiler output will change before 5.0 is released!
+import * as $ from "svelte/internal/server";
+
+export default function Bind_this($$payload, $$props) {
+	$.push(false);
+
+	const anchor = $.create_anchor($$payload);
+
+	$$payload.out += `${anchor}`;
+	Foo($$payload, {});
+	$$payload.out += `${anchor}`;
+	$.pop();
+}

packages/svelte/tests/snapshot/samples/bind-this/index.svelte

@@ -0,0 +1 @@
+<Foo bind:this={foo} />