diff --git a/src/wtf_string_mutable.zig b/src/wtf_string_mutable.zig
deleted file mode 100644
index 2d1aac522f4677..00000000000000
--- a/src/wtf_string_mutable.zig
+++ /dev/null
@@ -1,243 +0,0 @@
-const std = @import("std");
-const expect = std.testing.expect;
-
-usingnamespace @import("string_types.zig");
-const strings = @import("string_immutable.zig");
-const js_lexer = @import("js_lexer.zig");
-const ListType = std.ArrayListUnmanaged(u16);
-pub const WTFStringMutable = struct {
-    allocator: *std.mem.Allocator,
-    list: ListType,
-
-    pub const Writer = std.io.Writer(*@This(), anyerror, WTFStringMutable.writeAll);
-    pub fn writer(self: *WTFStringMutable) Writer {
-        return Writer{
-            .context = self,
-        };
-    }
-
-    pub fn deinit(str: *WTFStringMutable) void {
-        str.list.deinit(str.allocator);
-    }
-
-    pub fn growIfNeeded(self: *WTFStringMutable, amount: usize) !void {
-        try self.list.ensureUnusedCapacity(self.allocator, amount);
-    }
-
-    pub fn write(self: *WTFStringMutable, bytes: anytype) !usize {
-        try self.list.appendSlice(self.allocator, bytes);
-        return bytes.len;
-    }
-
-    pub fn writeAll(self: *WTFStringMutable, bytes: string) !usize {
-        try self.list.appendSlice(self.allocator, bytes);
-        return self.list.items.len;
-    }
-
-    pub fn init(allocator: *std.mem.Allocator, capacity: usize) !WTFStringMutable {
-        return WTFStringMutable{ .allocator = allocator, .list = try ListType.initCapacity(allocator, capacity) };
-    }
-
-    pub fn initCopy(allocator: *std.mem.Allocator, str: anytype) !WTFStringMutable {
-        var mutable = try WTFStringMutable.init(allocator, std.mem.len(str));
-        try mutable.copy(str);
-        return mutable;
-    }
-
-    // Convert it to an ASCII identifier. Note: If you change this to a non-ASCII
-    // identifier, you're going to potentially cause trouble with non-BMP code
-    // points in target environments that don't support bracketed Unicode escapes.
-
-    pub fn ensureValidIdentifier(str: string, allocator: *std.mem.Allocator) !string {
-        if (str.len == 0) {
-            return "_";
-        }
-
-        var has_needed_gap = false;
-        var needs_gap = false;
-        var start_i: usize = 0;
-
-        // Common case: no gap necessary. No allocation necessary.
-        needs_gap = !js_lexer.isIdentifierStart(@intCast(js_lexer.CodePoint, str[0]));
-        if (!needs_gap) {
-            // Are there any non-alphanumeric chars at all?
-            for (str[1..str.len]) |c, i| {
-                if (!js_lexer.isIdentifierContinue(@intCast(js_lexer.CodePoint, c))) {
-                    needs_gap = true;
-                    start_i = 1 + i;
-                    break;
-                }
-            }
-        }
-
-        if (needs_gap) {
-            var mutable = try WTFStringMutable.initCopy(allocator, str[0..start_i]);
-            needs_gap = false;
-
-            var i: usize = 0;
-
-            var slice = str[start_i..];
-
-            while (i < slice.len) : (i += 1) {
-                const c = @intCast(js_lexer.CodePoint, slice[i]);
-                if (js_lexer.isIdentifierContinue(c)) {
-                    if (needs_gap) {
-                        try mutable.appendChar('_');
-                        needs_gap = false;
-                        has_needed_gap = true;
-                    }
-
-                    try mutable.appendChar(slice[i]);
-                } else if (!needs_gap) {
-                    needs_gap = true;
-                    // skip the code point, replace it with a single _
-                    i += std.math.max(strings.utf8ByteSequenceLength(slice[i]), 1) - 1;
-                }
-            }
-
-            // If it ends with an emoji
-            if (needs_gap) {
-                try mutable.appendChar('_');
-                needs_gap = false;
-                has_needed_gap = true;
-            }
-
-            return mutable.list.toOwnedSlice(allocator);
-        }
-
-        return str;
-    }
-
-    pub fn len(self: *const WTFStringMutable) usize {
-        return self.list.items.len;
-    }
-
-    pub fn copy(self: *WTFStringMutable, str: anytype) !void {
-        try self.list.ensureCapacity(self.allocator, std.mem.len(str[0..]));
-
-        if (self.list.items.len == 0) {
-            try self.list.insertSlice(self.allocator, 0, str);
-        } else {
-            try self.list.replaceRange(self.allocator, 0, std.mem.len(str[0..]), str[0..]);
-        }
-    }
-
-    pub inline fn growBy(self: *WTFStringMutable, amount: usize) !void {
-        try self.list.ensureUnusedCapacity(self.allocator, amount);
-    }
-
-    pub inline fn reset(
-        self: *WTFStringMutable,
-    ) void {
-        self.list.shrinkRetainingCapacity(0);
-    }
-
-    pub inline fn appendChar(self: *WTFStringMutable, char: u8) !void {
-        try self.list.append(self.allocator, char);
-    }
-    pub inline fn appendCharAssumeCapacity(self: *WTFStringMutable, char: u8) void {
-        self.list.appendAssumeCapacity(char);
-    }
-    pub inline fn append(self: *WTFStringMutable, str: []const u8) !void {
-        try self.growIfNeeded(str.len);
-
-        var iter = strings.CodepointIterator{ .bytes = str, .i = 0 };
-        while (true) {
-            switch (iter.nextCodepoint()) {
-                -1 => {
-                    return;
-                },
-                0...0xFFFF => {
-                    try self.list.append(self.allocator, @intCast(u16, iter.c));
-                },
-                else => {
-                    const c = iter.c - 0x10000;
-                    try self.list.append(self.allocator, @intCast(u16, 0xD800 + ((c >> 10) & 0x3FF)));
-                    try self.list.append(self.allocator, @intCast(u16, 0xDC00 + (c & 0x3FF)));
-                },
-            }
-        }
-    }
-
-    pub inline fn appendComptimeConvert(self: *WTFStringMutable, comptime _str: []const u8) !void {
-        const str = std.unicode.utf8ToUtf16LeStringLiteral(_str);
-        try self.list.appendSlice(str);
-    }
-
-    pub inline fn appendAssumeCapacity(self: *WTFStringMutable, str: []const u8) void {
-        var iter = strings.CodepointIterator{ .bytes = str, .i = 0 };
-        while (true) {
-            switch (iter.nextCodepoint()) {
-                -1 => {
-                    return;
-                },
-                0...0xFFFF => {
-                    self.list.appendAssumeCapacity(@intCast(u16, iter.c));
-                },
-                else => {
-                    const c = iter.c - 0x10000;
-                    self.list.appendAssumeCapacity(@intCast(u16, 0xD800 + ((c >> 10) & 0x3FF)));
-                    self.list.appendAssumeCapacity(@intCast(u16, 0xDC00 + (c & 0x3FF)));
-                },
-            }
-        }
-    }
-    pub inline fn lenI(self: *WTFStringMutable) i32 {
-        return @intCast(i32, self.list.items.len);
-    }
-
-    pub fn toOwnedSlice(self: *WTFStringMutable) []u16 {
-        return self.list.toOwnedSlice(self.allocator);
-    }
-
-    pub fn toOwnedSliceLeaky(self: *WTFStringMutable) []u16 {
-        return self.list.items;
-    }
-
-    pub fn toOwnedSliceLength(self: *WTFStringMutable, length: usize)  {
-        self.list.shrinkAndFree(self.allocator, length);
-        return self.list.toOwnedSlice(self.allocator);
-    }
-
-    // pub fn deleteAt(self: *WTFStringMutable, i: usize)  {
-    //     self.list.swapRemove(i);
-    // }
-
-    pub fn containsChar(self: *WTFStringMutable, char: u8) bool {
-        return self.indexOfChar(char) != null;
-    }
-
-    pub fn indexOfChar(self: *WTFStringMutable, char: u8) ?usize {
-        return std.mem.indexOfScalar(@TypeOf(char), self.list.items, char);
-    }
-
-    pub fn lastIndexOfChar(self: *WTFStringMutable, char: u8) ?usize {
-        return std.mem.lastIndexOfScalar(@TypeOf(char), self.list.items, char);
-    }
-
-    pub fn lastIndexOf(self: *WTFStringMutable, str: u8) ?usize {
-        return std.mem.lastIndexOf(u8, self.list.items, str);
-    }
-
-    pub fn indexOf(self: *WTFStringMutable, str: u8) ?usize {
-        return std.mem.indexOf(u8, self.list.items, str);
-    }
-
-    pub fn eql(self: *WTFStringMutable, other: anytype) bool {
-        return std.mem.eql(u8, self.list.items, other);
-    }
-};
-
-test "WTFStringMutable" {
-    const alloc = std.heap.page_allocator;
-
-    var str = try WTFStringMutable.initCopy(alloc, "hello");
-    expect(str.eql("hello"));
-}
-
-test "WTFStringMutable.ensureValidIdentifier" {
-    const alloc = std.heap.page_allocator;
-
-    try std.testing.expectEqualStrings("jquery", try WTFStringMutable.ensureValidIdentifier("jquery", alloc));
-    try std.testing.expectEqualStrings("jquery_foo", try WTFStringMutable.ensureValidIdentifier("jquery😋foo", alloc));
-}