fix zig fmt out of bounds on empty file

2 files changed, 8 insertions, 0 deletions

diff --git a/lib/std/zig/parser_test.zig b/lib/std/zig/parser_test.zig
index 641ff37eea..c8e7abd5cb 100644
--- a/lib/std/zig/parser_test.zig
+++ b/lib/std/zig/parser_test.zig
@@ -223,6 +223,12 @@ test "recovery: missing block after for/while loops" {
     });
 }
 
+test "zig fmt: empty file" {
+    try testCanonical(
+        \\
+    );
+}
+
 test "zig fmt: if statment" {
     try testCanonical(
         \\test "" {
diff --git a/lib/std/zig/render.zig b/lib/std/zig/render.zig
index 79ab13e80e..54fa2e39f3 100644
--- a/lib/std/zig/render.zig
+++ b/lib/std/zig/render.zig
@@ -82,6 +82,8 @@ fn renderRoot(
     var start_col: usize = 0;
     var decl_i: ast.NodeIndex = 0;
     const root_decls = tree.root_node.decls();
+
+    if (root_decls.len == 0) return;
     while (true) {
         var decl = root_decls[decl_i];