fix: apply transition_in/out to svelte:element with local transition (#8865)

fixes #8233

Author: hackape

.changeset/neat-feet-accept.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: apply transition to `<svelte:element>` with local transition

packages/svelte/src/compiler/compile/render_dom/wrappers/Element/index.js

@@ -233,6 +233,14 @@ export default class ElementWrapper extends Wrapper {
 strip_whitespace,
 next_sibling
 );
+
+// in the case of `parent_block -> child_dynamic_element_block -> child_dynamic_element`
+// `child_dynamic_element_block.add_intro/outro` is called inside `new ElementWrapper()`
+// but when `is_local === true` it does not bubble to parent_block
+// we manually add transitions back to the parent_block (#8233)
+if (node.intro) block.add_intro(node.intro.is_local);
+if (node.outro) block.add_outro(node.outro.is_local);
+
 // the original svelte:element is never used for rendering, because
 // it gets assigned a child_dynamic_element which is used in all rendering logic.
 // so doing all of this on the original svelte:element will just cause double
@@ -266,10 +274,10 @@ export default class ElementWrapper extends Wrapper {
 this.event_handlers = this.node.handlers.map(
 (event_handler) => new EventHandler(event_handler, this)
 );
-if (node.intro || node.outro) {
-if (node.intro) block.add_intro(node.intro.is_local);
-if (node.outro) block.add_outro(node.outro.is_local);
-}
+
+if (node.intro) block.add_intro(node.intro.is_local);
+if (node.outro) block.add_outro(node.outro.is_local);
+
 if (node.animation) {
 block.add_animation();
 }