From 91265aee7880a4d375d58792822573b31c90f864 Mon Sep 17 00:00:00 2001
From: gtmnayan <50981692+gtm-nayan@users.noreply.github.com>
Date: Thu, 22 Jun 2023 21:05:52 +0545
Subject: [PATCH] fix: handle missing fields in migrate script (#10221)

---
 .changeset/tame-boats-attend.md                 | 5 +++++
 packages/migrate/migrations/svelte-4/migrate.js | 8 ++++----
 2 files changed, 9 insertions(+), 4 deletions(-)
 create mode 100644 .changeset/tame-boats-attend.md

diff --git a/.changeset/tame-boats-attend.md b/.changeset/tame-boats-attend.md
new file mode 100644
index 000000000000..55d564c6c0b2
--- /dev/null
+++ b/.changeset/tame-boats-attend.md
@@ -0,0 +1,5 @@
+---
+'svelte-migrate': patch
+---
+
+fix: handle missing fields in migrate script
diff --git a/packages/migrate/migrations/svelte-4/migrate.js b/packages/migrate/migrations/svelte-4/migrate.js
index 200fd5332fc7..f36395a038ee 100644
--- a/packages/migrate/migrations/svelte-4/migrate.js
+++ b/packages/migrate/migrations/svelte-4/migrate.js
@@ -21,12 +21,12 @@ export function update_pkg_json_content(content) {
 	 * @param {string} [additional]
 	 */
 	function update_pkg(name, version, additional = '') {
-		if (pkg.dependencies[name]) {
-			log_migration(`Updated ${name} to ${version}${additional}`);
+		if (pkg.dependencies?.[name]) {
+			log_migration(`Updated ${name} to ${version} ${additional}`);
 			pkg.dependencies[name] = version;
 		}
-		if (pkg.devDependencies[name]) {
-			log_migration(`Updated ${name} to ${version}${additional}`);
+		if (pkg.devDependencies?.[name]) {
+			log_migration(`Updated ${name} to ${version} ${additional}`);
 			pkg.devDependencies[name] = version;
 		}
 	}