diff --git a/build.zig b/build.zig
index 833099c..107b584 100644
--- a/build.zig
+++ b/build.zig
@@ -621,6 +621,67 @@ pub fn build_exe(
         },
     });
 
+    const helix_mod = b.createModule(.{
+        .root_source_file = b.path("src/tui/mode/helix.zig"),
+    });
+    // const editor_mod = b.createModule(.{
+    //     .root_source_file = b.path("src/tui/editor.zig"),
+    // });
+    // const Widget_mod = b.createModule(.{
+    //     .root_source_file = b.path("src/tui/Widget.zig"),
+    // });
+    // const mainview_mod = b.createModule(.{
+    //     .root_source_file = b.path("src/tui/mainview.zig"),
+    // });
+    // const WidgetList_mod = b.createModule(.{
+    //     .root_source_file = b.path("src/tui/WidgetList.zig"),
+    // });
+    // const MessageFilter_mod = b.createModule(.{
+    //     .root_source_file = b.path("src/tui/MessageFilter.zig"),
+    // });
+    // const editor_gutter_mod = b.createModule(.{
+    //     .root_source_file = b.path("src/tui/editor_gutter.zig"),
+    // });
+    // const scrollbar_v_mod = b.createModule(.{
+    //     .root_source_file = b.path("src/tui//scrollbar_v.zig"),
+    // });
+    // const palette_mod = b.createModule(.{
+    //     .root_source_file = b.path("src/tui/mode/overlay/palette.zig"),
+    // });
+    // const open_recent_project_mod = b.createModule(.{
+    //     .root_source_file = b.path("src/tui/mode/overlay/open_recent_project.zig"),
+    // });
+
+    // const helix_test_run_cmd = blk: {
+    //     const tests = b.addTest(.{
+    //         .root_module = b.createModule(.{
+    //             .root_source_file = b.path("src/tui/mode/helix.zig"),
+    //             .target = target,
+    //             .optimize = optimize,
+    //         }),
+    //     });
+    //     tests.root_module.addImport("cbor", cbor_mod);
+    //     tests.root_module.addImport("command", command_mod);
+    //     tests.root_module.addImport("EventHandler", EventHandler_mod);
+    //     tests.root_module.addImport("input", input_mod);
+    //     tests.root_module.addImport("thespian", thespian_mod);
+    //     tests.root_module.addImport("log", log_mod);
+    //     tests.root_module.addImport("tui", tui_mod);
+    //     tests.root_module.addImport("helix", helix_mod);
+    //     tests.root_module.addImport("editor", editor_mod);
+    //     tests.root_module.addImport("Widget", Widget_mod);
+    //     tests.root_module.addImport("WidgetList", WidgetList_mod);
+    //     tests.root_module.addImport("mainview", mainview_mod);
+    //     tests.root_module.addImport("Buffer", Buffer_mod);
+    //     tests.root_module.addImport("MessageFilter", MessageFilter_mod);
+    //     tests.root_module.addImport("editor_gutter", editor_gutter_mod);
+    //     tests.root_module.addImport("scrollbar_v", scrollbar_v_mod);
+    //     tests.root_module.addImport("palette", palette_mod);
+    //     tests.root_module.addImport("open_recent_project", open_recent_project_mod);
+    //     tests.root_module.addImport("renderer", renderer_mod);
+    //     break :blk b.addRunArtifact(tests);
+    // };
+
     const exe_name = if (gui) "flow-gui" else "flow";
 
     const exe = b.addExecutable(.{
@@ -712,6 +773,7 @@ pub fn build_exe(
     check_exe.root_module.addImport("version_info", b.createModule(.{ .root_source_file = version_info_file }));
     check_step.dependOn(&check_exe.step);
 
+    const test_filters = b.option([]const []const u8, "test-filter", "Skip tests that do not match any filter") orelse &[0][]const u8{};
     const tests = b.addTest(.{
         .root_module = b.createModule(.{
             .root_source_file = b.path("test/tests.zig"),
@@ -721,6 +783,7 @@ pub fn build_exe(
         }),
         .use_llvm = use_llvm,
         .use_lld = use_llvm,
+        .filters = test_filters,
     });
 
     tests.pie = pie;
@@ -730,6 +793,7 @@ pub fn build_exe(
     tests.root_module.addImport("log", log_mod);
     tests.root_module.addImport("Buffer", Buffer_mod);
     tests.root_module.addImport("color", color_mod);
+    tests.root_module.addImport("helix", helix_mod);
     // b.installArtifact(tests);
 
     const test_run_cmd = b.addRunArtifact(tests);
diff --git a/src/tui/editor.zig b/src/tui/editor.zig
index 791b669..211e62a 100644
--- a/src/tui/editor.zig
+++ b/src/tui/editor.zig
@@ -2143,11 +2143,11 @@ pub const Editor = struct {
         return false;
     }
 
-    fn is_whitespace(c: []const u8) bool {
+    pub fn is_whitespace(c: []const u8) bool {
         return (c.len == 0) or (c[0] == ' ') or (c[0] == '\t');
     }
 
-    fn is_whitespace_or_eol(c: []const u8) bool {
+    pub fn is_whitespace_or_eol(c: []const u8) bool {
         return is_whitespace(c) or c[0] == '\n';
     }
 
diff --git a/src/tui/mode/helix.zig b/src/tui/mode/helix.zig
index 9a0e589..c0f3a6b 100644
--- a/src/tui/mode/helix.zig
+++ b/src/tui/mode/helix.zig
@@ -232,6 +232,20 @@ const cmds_ = struct {
     }
     pub const move_next_word_start_meta: Meta = .{ .description = "Move next word start", .arguments = &.{.integer} };
 
+    pub fn move_next_long_word_start(_: *void, ctx: Ctx) Result {
+        const mv = tui.mainview() orelse return;
+        const ed = mv.get_active_editor() orelse return;
+        const root = try ed.buf_root();
+
+        for (ed.cursels.items) |*cursel_| if (cursel_.*) |*cursel| {
+            cursel.selection = null;
+        };
+
+        ed.with_selections_const_repeat(root, move_cursor_long_word_right, ctx) catch {};
+        ed.clamp();
+    }
+    pub const move_next_long_word_start_meta: Meta = .{ .description = "Move next long word start", .arguments = &.{.integer} };
+
     pub fn move_prev_word_start(_: *void, ctx: Ctx) Result {
         const mv = tui.mainview() orelse return;
         const ed = mv.get_active_editor() orelse return;
@@ -246,6 +260,20 @@ const cmds_ = struct {
     }
     pub const move_prev_word_start_meta: Meta = .{ .description = "Move previous word start", .arguments = &.{.integer} };
 
+    pub fn move_prev_long_word_start(_: *void, ctx: Ctx) Result {
+        const mv = tui.mainview() orelse return;
+        const ed = mv.get_active_editor() orelse return;
+        const root = try ed.buf_root();
+
+        for (ed.cursels.items) |*cursel_| if (cursel_.*) |*cursel| {
+            cursel.selection = null;
+        };
+
+        ed.with_selections_const_repeat(root, move_cursor_long_word_left, ctx) catch {};
+        ed.clamp();
+    }
+    pub const move_prev_long_word_start_meta: Meta = .{ .description = "Move previous long word start", .arguments = &.{.integer} };
+
     pub fn move_next_word_end(_: *void, ctx: Ctx) Result {
         const mv = tui.mainview() orelse return;
         const ed = mv.get_active_editor() orelse return;
@@ -260,6 +288,20 @@ const cmds_ = struct {
     }
     pub const move_next_word_end_meta: Meta = .{ .description = "Move next word end", .arguments = &.{.integer} };
 
+    pub fn move_next_long_word_end(_: *void, ctx: Ctx) Result {
+        const mv = tui.mainview() orelse return;
+        const ed = mv.get_active_editor() orelse return;
+        const root = try ed.buf_root();
+
+        for (ed.cursels.items) |*cursel_| if (cursel_.*) |*cursel| {
+            cursel.selection = null;
+        };
+
+        ed.with_selections_const_repeat(root, move_cursor_long_word_right_end, ctx) catch {};
+        ed.clamp();
+    }
+    pub const move_next_long_word_end_meta: Meta = .{ .description = "Move next long word end", .arguments = &.{.integer} };
+
     pub fn cut_forward_internal_inclusive(_: *void, _: Ctx) Result {
         const mv = tui.mainview() orelse return;
         const ed = mv.get_active_editor() orelse return;
@@ -467,3 +509,88 @@ fn insert_line(ed: *Editor, root: Buffer.Root, cursel: *CurSel, s: []const u8, a
     cursel.selection = Selection{ .begin = begin, .end = cursor.* };
     return root_;
 }
+
+fn is_not_whitespace_or_eol(c: []const u8) bool {
+    return !Editor.is_whitespace_or_eol(c);
+}
+
+fn is_whitespace_or_eol_at_cursor(root: Buffer.Root, cursor: *const Cursor, metrics: Buffer.Metrics) bool {
+    return cursor.test_at(root, Editor.is_whitespace_or_eol, metrics);
+}
+
+fn is_non_whitespace_or_eol_at_cursor(root: Buffer.Root, cursor: *const Cursor, metrics: Buffer.Metrics) bool {
+    return cursor.test_at(root, is_not_whitespace_or_eol, metrics);
+}
+
+fn is_long_word_boundary_left(root: Buffer.Root, cursor: *const Cursor, metrics: Buffer.Metrics) bool {
+    if (cursor.test_at(root, Editor.is_whitespace, metrics)) return false;
+    var next = cursor.*;
+    next.move_left(root, metrics) catch return true;
+
+    const next_is_whitespace = Editor.is_whitespace_at_cursor(root, &next, metrics);
+    if (next_is_whitespace) return true;
+
+    const curr_is_non_word = is_non_whitespace_or_eol_at_cursor(root, cursor, metrics);
+    const next_is_non_word = is_non_whitespace_or_eol_at_cursor(root, &next, metrics);
+    return curr_is_non_word != next_is_non_word;
+}
+
+pub fn move_cursor_long_word_left(root: Buffer.Root, cursor: *Cursor, metrics: Buffer.Metrics) error{Stop}!void {
+    try Editor.move_cursor_left(root, cursor, metrics);
+
+    // Consume " "
+    while (Editor.is_whitespace_at_cursor(root, cursor, metrics)) {
+        try Editor.move_cursor_left(root, cursor, metrics);
+    }
+
+    var next = cursor.*;
+    next.move_left(root, metrics) catch return;
+    var next_next = next;
+    next_next.move_left(root, metrics) catch return;
+
+    const cur = next.test_at(root, is_not_whitespace_or_eol, metrics);
+    const nxt = next_next.test_at(root, is_not_whitespace_or_eol, metrics);
+    if (cur != nxt) {
+        try Editor.move_cursor_left(root, cursor, metrics);
+        return;
+    } else {
+        try move_cursor_long_word_left(root, cursor, metrics);
+    }
+}
+
+fn is_word_boundary_right(root: Buffer.Root, cursor: *const Cursor, metrics: Buffer.Metrics) bool {
+    if (Editor.is_whitespace_at_cursor(root, cursor, metrics)) return false;
+    var next = cursor.*;
+    next.move_right(root, metrics) catch return true;
+
+    const next_is_whitespace = Editor.is_whitespace_at_cursor(root, &next, metrics);
+    if (next_is_whitespace) return true;
+
+    const curr_is_non_word = is_non_whitespace_or_eol_at_cursor(root, cursor, metrics);
+    const next_is_non_word = is_non_whitespace_or_eol_at_cursor(root, &next, metrics);
+    return curr_is_non_word != next_is_non_word;
+}
+
+pub fn move_cursor_long_word_right(root: Buffer.Root, cursor: *Cursor, metrics: Buffer.Metrics) error{Stop}!void {
+    try cursor.move_right(root, metrics);
+    Editor.move_cursor_right_until(root, cursor, is_long_word_boundary_left, metrics);
+}
+
+fn is_long_word_boundary_right(root: Buffer.Root, cursor: *const Cursor, metrics: Buffer.Metrics) bool {
+    if (Editor.is_whitespace_at_cursor(root, cursor, metrics)) return false;
+    var next = cursor.*;
+    next.move_right(root, metrics) catch return true;
+
+    const next_is_whitespace = Editor.is_whitespace_at_cursor(root, &next, metrics);
+    if (next_is_whitespace) return true;
+
+    const curr_is_non_word = is_non_whitespace_or_eol_at_cursor(root, cursor, metrics);
+    const next_is_non_word = is_non_whitespace_or_eol_at_cursor(root, &next, metrics);
+    return curr_is_non_word != next_is_non_word;
+}
+
+pub fn move_cursor_long_word_right_end(root: Buffer.Root, cursor: *Cursor, metrics: Buffer.Metrics) error{Stop}!void {
+    // try Editor.move_cursor_right(root, cursor, metrics);
+    Editor.move_cursor_right_until(root, cursor, is_long_word_boundary_right, metrics);
+    try cursor.move_right(root, metrics);
+}
diff --git a/test/tests.zig b/test/tests.zig
index 49c5e96..af75213 100644
--- a/test/tests.zig
+++ b/test/tests.zig
@@ -1,6 +1,7 @@
 const std = @import("std");
 pub const buffer = @import("tests_buffer.zig");
 pub const color = @import("tests_color.zig");
+pub const helix = @import("tests_helix.zig");
 
 test {
     std.testing.refAllDecls(@This());
diff --git a/test/tests_helix.zig b/test/tests_helix.zig
new file mode 100644
index 0000000..69d5628
--- /dev/null
+++ b/test/tests_helix.zig
@@ -0,0 +1,79 @@
+const std = @import("std");
+const Buffer = @import("Buffer");
+const Cursor = @import("Cursor");
+const helix = @import("helix");
+
+// error: import of file outside module path
+// const helix = @import("../src/tui/mode/helix.zig");
+
+const ArrayList = std.ArrayList;
+const a = std.testing.allocator;
+
+fn metrics() Buffer.Metrics {
+    return .{
+        .ctx = undefined,
+        .egc_length = struct {
+            fn f(_: Buffer.Metrics, _: []const u8, colcount: *c_int, _: usize) usize {
+                colcount.* = 1;
+                return 1;
+            }
+        }.f,
+        .egc_chunk_width = struct {
+            fn f(_: Buffer.Metrics, chunk_: []const u8, _: usize) usize {
+                return chunk_.len;
+            }
+        }.f,
+        .egc_last = struct {
+            fn f(_: Buffer.Metrics, _: []const u8) []const u8 {
+                @panic("not implemented");
+            }
+        }.f,
+        .tab_width = 8,
+    };
+}
+
+fn the_pos(buffer: Buffer, pos: u8) Cursor {
+    return buffer.root.byte_offset_to_line_and_col(pos, metrics(), .lf);
+}
+
+test "word_movement" {
+    const W = helix.move_cursor_long_word_right;
+    const B = helix.move_cursor_long_word_left;
+    const E = helix.move_cursor_long_word_right_end;
+    const doc: []const u8 =
+        \\a small $% Test.here,   with.things()to demo
+        \\ with surrounding.space    a bb  AA   a small and long
+        \\
+        \\  
+        \\nospace.
+        \\   try std.testing.expectEqual(Buffer.Cursor{ .row = 0, .col = 0 }, buffer.root.byte_offset_to_line_and_col(0, test_metrics(), eol_mode));
+        \\
+        \\
+        \\  $$%.  []{{}. dart de
+        \\da
+    ;
+
+    //44 55 0 8 0
+    // TODO: test selections. Parity with Helix
+
+    var eol_mode: Buffer.EolMode = .lf;
+    var sanitized: bool = false;
+    const buffer = try Buffer.create(a);
+    defer buffer.deinit();
+    buffer.update(try buffer.load_from_string(doc, &eol_mode, &sanitized));
+    const root: Buffer.Root = buffer.root;
+    var c = Cursor{ .row = 0, .col = 0, .target = 0 };
+    const t = the_pos;
+
+    try std.testing.expectEqual(Buffer.Cursor{ .row = 0, .col = 0 }, buffer.root.byte_offset_to_line_and_col(0, metrics(), eol_mode));
+    try std.testing.expectEqual(try buffer.root.line_width(0, metrics()), 44);
+    try std.testing.expectEqual(try buffer.root.line_width(1, metrics()), 55);
+    try E(root, &c, metrics());
+    try std.testing.expectEqual(c, t(buffer.*, 1));
+    try B(root, &c, metrics());
+    try std.testing.expectEqual(c, t(buffer.*, 0));
+    try W(root, &c, metrics());
+    try std.testing.expectEqual(c, t(buffer.*, 2));
+    try B(root, &c, metrics());
+    try std.testing.expectEqual(c, t(buffer.*, 1));
+}