From 14f1fe97f07d9cab4823dc8cc92614d23aedaa56 Mon Sep 17 00:00:00 2001
From: Malte Ubl <malte@vercel.com>
Date: Tue, 20 Oct 2026 01:20:56 -0700
Subject: [PATCH] Keep a hoisted class's next piece when the initializer ends
 with it
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In minified output the class closes right where the initializer body
does (`…Counter=class{…}}})`), so the empty insertion that opens the next
run-once piece shared its position with the body's closing edit and was
dropped: the initializer then called a piece that did not exist. The
opener now rides on the class's own closing brace.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 .../frontend/npm-static-bundled-esm.test.ts   |  7 +++++++
 .../src/frontend/npm-static-bundled-esm.ts    | 21 ++++++++++++++-----
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/packages/compiler/src/frontend/npm-static-bundled-esm.test.ts b/packages/compiler/src/frontend/npm-static-bundled-esm.test.ts
index ac3811594..ea1c22ce5 100644
--- a/packages/compiler/src/frontend/npm-static-bundled-esm.test.ts
+++ b/packages/compiler/src/frontend/npm-static-bundled-esm.test.ts
@@ -256,3 +256,10 @@ console.log(typeof make().on);
 `);
   expect(lowered).toContain('new (require("events")).EventEmitter()');
 });
+
+test("a minified initializer that ends with its class still hoists it", () => {
+  const lowered = expectSameBehavior(
+    `${helpers}var Counter;var init_counter=__esm({"src/counter.ts"(){console.log("counter init"),Counter=class{n=0;next(){return++this.n}}}});function run(){init_counter();const c=new Counter;c.next();console.log(c.next())}run();`,
+  );
+  expect(lowered).toContain("class Counter{");
+});
diff --git a/packages/compiler/src/frontend/npm-static-bundled-esm.ts b/packages/compiler/src/frontend/npm-static-bundled-esm.ts
index e4beb240c..f38d4117d 100644
--- a/packages/compiler/src/frontend/npm-static-bundled-esm.ts
+++ b/packages/compiler/src/frontend/npm-static-bundled-esm.ts
@@ -984,11 +984,22 @@ function hoistInitClasses(
         hoistedEls.add(el);
         edits.push({ start: from, end: cls.getStart(sf), text: `${sep} ${rest}(); ${close} ` });
         const next = els[i + 1];
-        edits.push({
-          start: cls.getEnd(),
-          end: next === undefined ? cls.getEnd() : next.getStart(sf),
-          text: ` function ${rest}() { ${strict}`,
-        });
+        // The class's own closing brace carries the next piece's opener: an
+        // empty insertion at its end would share its position with the
+        // initializer body's closing edit in minified text (`…}}})`).
+        edits.push(
+          next === undefined
+            ? {
+                start: cls.getEnd() - 1,
+                end: cls.getEnd(),
+                text: `} function ${rest}() { ${strict}`,
+              }
+            : {
+                start: cls.getEnd(),
+                end: next.getStart(sf),
+                text: ` function ${rest}() { ${strict}`,
+              },
+        );
         if (cls.name === undefined) {
           const keyword = cls.getStart(sf);
           edits.push({ start: keyword, end: keyword + "class".length, text: `class ${name}` });