From 2600ffea2bd241c57f3ab48bfbf799f585778955 Mon Sep 17 00:00:00 2001
From: sliang-code <sihanlia@andrew.cmu.edu>
Date: Fri, 1 May 2026 02:05:44 -0400
Subject: [PATCH] feat: Implement getOrInsert and getOrInsertComputed methods

Add methods to get or insert values in the map.
---
 packages/svelte/src/reactivity/map.js | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/packages/svelte/src/reactivity/map.js b/packages/svelte/src/reactivity/map.js
index 48d06a05a7..8043c40966 100644
--- a/packages/svelte/src/reactivity/map.js
+++ b/packages/svelte/src/reactivity/map.js
@@ -153,6 +153,22 @@ export class SvelteMap extends Map {
 		return super.get(key);
 	}
 
+	getOrInsert(key, value) {
+		if (super.has(key)) {
+			return /** @type {V} */ (super.get(key));
+		}
+		this.set(key, value);
+		return super.get(key);
+	}
+
+	getOrInsertComputed(key, callbackfn) {
+		if (super.has(key)) {
+			return /** @type {V} */ (super.get(key));
+		}
+		this.set(key, callbackfn(key));
+		return super.get(key);
+	}
+
 	/**
 	 * @param {K} key
 	 * @param {V} value