From 4b6bf29b83d5c191bc14c9ea2e9ab9a546eb7e02 Mon Sep 17 00:00:00 2001
From: Karl Seguin <k@openmymind.io>
Date: Sun, 15 Mar 2026 09:55:13 +0800
Subject: [PATCH] Improve ergonomics around rejecting a promise with a proper
 JS error

---
 src/browser/js/PromiseResolver.zig | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/browser/js/PromiseResolver.zig b/src/browser/js/PromiseResolver.zig
index f2aac0e0..d02740ac 100644
--- a/src/browser/js/PromiseResolver.zig
+++ b/src/browser/js/PromiseResolver.zig
@@ -63,6 +63,20 @@ pub fn reject(self: PromiseResolver, comptime source: []const u8, value: anytype
     };
 }
 
+const RejectError = union(enum) {
+    generic: []const u8,
+    type_error: []const u8,
+};
+pub fn rejectError(self: PromiseResolver, comptime source: []const u8, err: RejectError) void {
+    const handle = switch (err) {
+        .type_error => |str| self.local.isolate.createTypeError(str),
+        .generic => |str| self.local.isolate.createError(str)
+    };
+    self._reject(js.Value{.handle = handle, .local = self.local}) catch |reject_err| {
+        log.err(.bug, "rejectError", .{ .source = source, .err = reject_err, .persistent = false });
+    };
+}
+
 fn _reject(self: PromiseResolver, value: anytype) !void {
     const local = self.local;
     const js_val = try local.zigValueToJs(value, .{});