Fixes #3530 (#3587)

* Fixes #3530

* Handle OOM

* Add test

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/src/string.zig b/src/string.zig
index 166a0a6f7..5f107197f 100644
--- a/src/string.zig
+++ b/src/string.zig
@@ -257,6 +257,8 @@ pub const String = extern struct {
 
     extern fn BunString__fromLatin1(bytes: [*]const u8, len: usize) String;
     extern fn BunString__fromBytes(bytes: [*]const u8, len: usize) String;
+    extern fn BunString__fromLatin1Unitialized(len: usize) String;
+    extern fn BunString__fromUTF16Unitialized(len: usize) String;
 
     pub fn toOwnedSlice(this: String, allocator: std.mem.Allocator) ![]u8 {
         switch (this.tag) {
@@ -278,6 +280,30 @@ pub const String = extern struct {
         }
     }
 
+    pub fn createUninitializedLatin1(len: usize) String {
+        JSC.markBinding(@src());
+        return BunString__fromLatin1Unitialized(len);
+    }
+
+    pub fn createUninitializedUTF16(len: usize) String {
+        JSC.markBinding(@src());
+        return BunString__fromUTF16Unitialized(len);
+    }
+
+    pub fn createUninitialized(comptime kind: @Type(.EnumLiteral), len: usize) ?String {
+        const without_check = switch (comptime kind) {
+            .latin1 => createUninitializedLatin1(len),
+            .utf16 => createUninitializedUTF16(len),
+            else => @compileError("Invalid string kind"),
+        };
+
+        if (without_check.tag == .Dead) {
+            return null;
+        }
+
+        return without_check;
+    }
+
     pub fn createLatin1(bytes: []const u8) String {
         JSC.markBinding(@src());
         return BunString__fromLatin1(bytes.ptr, bytes.len);