From 815055c6c59e7f50e58998fafe594455be101282 Mon Sep 17 00:00:00 2001
From: Dylan Piercey <pierceydylan@gmail.com>
Date: Thu, 25 Jun 2026 22:57:01 +0000
Subject: [PATCH] fix(expression): end type annotation at function body brace

A `{` following a completed type now ends the return type annotation so a
`>` in the body is no longer parsed as a closing generic bracket.

Fixes #215
---
 .changeset/statement-fn-return-type-body.md   | 13 +++++++++++
 ...tatement-function-return-type.expected.txt | 23 +++++++++++++++++++
 .../input.marko                               | 13 +++++++++++
 src/states/EXPRESSION.ts                      | 10 ++++++++
 4 files changed, 59 insertions(+)
 create mode 100644 .changeset/statement-fn-return-type-body.md
 create mode 100644 src/__tests__/fixtures/ts-statement-function-return-type/__snapshots__/ts-statement-function-return-type.expected.txt
 create mode 100644 src/__tests__/fixtures/ts-statement-function-return-type/input.marko

diff --git a/.changeset/statement-fn-return-type-body.md b/.changeset/statement-fn-return-type-body.md
new file mode 100644
index 00000000..f86fc6bd
--- /dev/null
+++ b/.changeset/statement-fn-return-type-body.md
@@ -0,0 +1,13 @@
+---
+"htmljs-parser": patch
+---
+
+Fix a spurious "Mismatched group" error when a `>` (or other comparison) appears in the body of a statement function that declares a return type, e.g.:
+
+```marko
+export function a(): b {
+  return c > d;
+}
+```
+
+Previously the type-parsing state from the return type annotation leaked into the function body, so a `>` was treated as a closing generic bracket. A `{` that follows a completed type now correctly ends the annotation and parses the block as a value.
diff --git a/src/__tests__/fixtures/ts-statement-function-return-type/__snapshots__/ts-statement-function-return-type.expected.txt b/src/__tests__/fixtures/ts-statement-function-return-type/__snapshots__/ts-statement-function-return-type.expected.txt
new file mode 100644
index 00000000..dd5bc2b5
--- /dev/null
+++ b/src/__tests__/fixtures/ts-statement-function-return-type/__snapshots__/ts-statement-function-return-type.expected.txt
@@ -0,0 +1,23 @@
+1╭─ export function a(): b {
+ ╰─ ╰─ tagName "export"
+2├─   return c > d;
+3├─ }
+4╭─ 
+ ╰─ ╰─ openTagEnd
+5╭─ static function e<T>(x: T): Array<T> {
+ ╰─ ╰─ tagName "static"
+6├─   return x > 0 ? f : g;
+7├─ }
+8╭─ 
+ ╰─ ╰─ openTagEnd
+9╭─ export function h(): { i: 1 } {
+ ╰─ ╰─ tagName "export"
+10├─   return j > k;
+11├─ }
+12╭─ 
+  ╰─ ╰─ openTagEnd
+13╭─ div
+  ╰─ ╰─ tagName "div"
+14╭─ 
+  │  ├─ openTagEnd
+  ╰─ ╰─ closeTagEnd(div)
\ No newline at end of file
diff --git a/src/__tests__/fixtures/ts-statement-function-return-type/input.marko b/src/__tests__/fixtures/ts-statement-function-return-type/input.marko
new file mode 100644
index 00000000..45551cdd
--- /dev/null
+++ b/src/__tests__/fixtures/ts-statement-function-return-type/input.marko
@@ -0,0 +1,13 @@
+export function a(): b {
+  return c > d;
+}
+
+static function e<T>(x: T): Array<T> {
+  return x > 0 ? f : g;
+}
+
+export function h(): { i: 1 } {
+  return j > k;
+}
+
+div
diff --git a/src/states/EXPRESSION.ts b/src/states/EXPRESSION.ts
index 6df0e367..a7e1bbb4 100644
--- a/src/states/EXPRESSION.ts
+++ b/src/states/EXPRESSION.ts
@@ -253,6 +253,16 @@ export const EXPRESSION: StateDefinition<ExpressionMeta> = {
           this.pos++;
           break;
         case CODE.OPEN_CURLY_BRACE:
+          if (expression.inType && !expression.forceType) {
+            const prevPos = lookBehindWhile(
+              isWhitespaceCode,
+              data,
+              this.pos - 1,
+            );
+            if (lookBehindForOperator(expression, data, prevPos) === -1) {
+              expression.inType = false;
+            }
+          }
           expression.groupStack.push(CODE.CLOSE_CURLY_BRACE);
           this.pos++;
           break;