lib/ui/src/style/test.zig

daab053ee43316e1809a84551d573ddd1e5bf3d2

  1 const std = @import("std");
  2 const css = @import("css");
  3 const abi = @import("../abi/root.zig");
  4 const tree = @import("../tree/root.zig");
  5 const element = @import("element.zig");
  6 const paint = @import("paint.zig");
  7 const asset = @import("../asset/root.zig");
  8 const generation = @import("generation.zig");
  9 const media = @import("media.zig");
 10 
 11 test {
 12     _ = @import("computed.zig");
 13     _ = @import("share.zig");
 14     _ = @import("generation.zig");
 15 }
 16 
 17 test "style element walks parents and siblings in a flat preorder tree" {
 18     const nodes = [_]abi.Node{
 19         .{ .id = 1, .subtree_count = 4, .kind = @backingInt(abi.Kind.box) },
 20         .{ .id = 2, .parent = 0, .subtree_count = 1, .kind = @backingInt(abi.Kind.box) },
 21         .{ .id = 3, .parent = 1, .kind = @backingInt(abi.Kind.text) },
 22         .{ .id = 4, .parent = 0, .kind = @backingInt(abi.Kind.box) },
 23         .{ .id = 5, .parent = 0, .kind = @backingInt(abi.Kind.text) },
 24     };
 25     const sheet = css.StyleSheet{};
 26     var adapter = element.Adapter{ .view = tree.View{ .nodes = &nodes }, .sheet = &sheet };
 27     const callback = adapter.element();
 28     try std.testing.expectEqual(@as(u32, 1), callback.parent(callback.context, 2));
 29     try std.testing.expectEqual(@as(u32, 1), callback.previous(callback.context, 3));
 30     try std.testing.expectEqual(@as(u32, 3), callback.previous(callback.context, 4));
 31     try std.testing.expectEqual(@as(u32, 1), callback.previous(callback.context, 1));
 32     try std.testing.expectEqual(css.match.packSibling(2, 3), callback.sibling_index(callback.context, 3, false));
 33 }
 34 
 35 test "style pseudo maps published state and derives interaction along ancestry" {
 36     const nodes = [_]abi.Node{
 37         .{ .id = 1, .subtree_count = 2 },
 38         .{ .id = 2, .parent = 0, .subtree_count = 1, .state = abi.state(.selected) },
 39         .{ .id = 3, .parent = 1 },
 40     };
 41     const sheet = css.StyleSheet{};
 42     var adapter = element.Adapter{
 43         .view = tree.View{ .nodes = &nodes },
 44         .sheet = &sheet,
 45         .interaction = .{ .hovered = 3, .focused = 3, .keyboard_focus = true },
 46     };
 47     const callback = adapter.element();
 48     const row = callback.pseudo(callback.context, 1);
 49     const cell = callback.pseudo(callback.context, 2);
 50     try std.testing.expect(row & css.selector.bit(.selected) != 0);
 51     try std.testing.expect(row & css.selector.bit(.hover) != 0);
 52     try std.testing.expect(row & css.selector.bit(.focus_within) != 0);
 53     try std.testing.expect(cell & css.selector.bit(.focus_visible) != 0);
 54     adapter.interaction.keyboard_focus = false;
 55     try std.testing.expect(callback.pseudo(callback.context, 2) & css.selector.bit(.focus_visible) == 0);
 56 }
 57 
 58 test "style paint records keep their declared byte layouts" {
 59     try std.testing.expectEqual(@as(usize, 84), @sizeOf(paint.Paint));
 60     try std.testing.expectEqual(@as(usize, 32), @sizeOf(paint.ImagePaint));
 61     try std.testing.expectEqual(@as(usize, 56), @sizeOf(paint.TextStyle));
 62 }
 63 
 64 test "style lowering resolves a registered primary face and refreshes on release" {
 65     const allocator = std.testing.allocator;
 66     var registry = try asset.Registry.init(allocator, .{ .fonts = 2, .images = 0, .owned_bytes = 0 });
 67     defer registry.deinit(allocator);
 68     registry.activate();
 69     const sans = try registry.registerFont("Noto Sans", .{}, .{ .borrowed = "" });
 70     const mono = try registry.registerFont("Iosevka", .{ .monospace = 1 }, .{ .borrowed = "" });
 71     var workspace = css.Workspace.init(allocator);
 72     defer workspace.deinit();
 73     const sheet = try workspace.parse("text { font-family: 'Iosevka', 'Noto Sans', Iosevka; font-weight: bold; }", .default());
 74     const nodes = [_]abi.Node{.{ .id = 1, .kind = @backingInt(abi.Kind.text) }};
 75     const view = tree.View{ .nodes = &nodes };
 76     var engine = try generation.Engine.init(allocator, .{ .nodes = 1, .distinct_styles = 4, .selectors = 4, .bytes = 16 * 1024 });
 77     defer engine.deinit(allocator);
 78     engine.activate();
 79     try engine.setFonts(&registry);
 80     _ = try engine.cascadeView(view, &.{0}, &sheet, 1, .{});
 81     try std.testing.expectEqual(mono, engine.record(0).text.face);
 82     try std.testing.expectEqualSlices(asset.AssetHandle, &.{sans}, engine.authoredFallbacks(0));
 83     try registry.release(.font, mono);
 84     const changed = try engine.cascadeView(view, &.{}, &sheet, 1, .{});
 85     try std.testing.expectEqual(@as(u32, 1), changed.restyled);
 86     try std.testing.expectEqual(sans, engine.record(0).text.face);
 87     try std.testing.expectEqual(@as(usize, 0), engine.authoredFallbacks(0).len);
 88 }
 89 
 90 test "stylesheet replacement resolves a new family with equal cascade bytes" {
 91     const allocator = std.testing.allocator;
 92     var registry = try asset.Registry.init(allocator, .{ .fonts = 2, .images = 0, .owned_bytes = 0 });
 93     defer registry.deinit(allocator);
 94     registry.activate();
 95     const first_face = try registry.registerFont("Iosevka", .{}, .{ .borrowed = "" });
 96     const second_face = try registry.registerFont("Fixture", .{}, .{ .borrowed = "" });
 97     var first_workspace = css.Workspace.init(allocator);
 98     defer first_workspace.deinit();
 99     var second_workspace = css.Workspace.init(allocator);
100     defer second_workspace.deinit();
101     const first = try first_workspace.parse("text { font-family: Iosevka; }", .default());
102     const second = try second_workspace.parse("text { font-family: Fixture; }", .default());
103     const nodes = [_]abi.Node{.{ .id = 1, .kind = @backingInt(abi.Kind.text) }};
104     const view = tree.View{ .nodes = &nodes };
105     var engine = try generation.Engine.init(allocator, .{ .nodes = 1, .distinct_styles = 4, .selectors = 4, .bytes = 16 * 1024 });
106     defer engine.deinit(allocator);
107     engine.activate();
108     try engine.setFonts(&registry);
109     _ = try engine.cascadeView(view, &.{0}, &first, 1, .{});
110     try std.testing.expectEqual(first_face, engine.record(0).text.face);
111     _ = try engine.cascadeView(view, &.{}, &second, 2, .{});
112     try std.testing.expectEqual(second_face, engine.record(0).text.face);
113 }
114 
115 test "style lowering reads an inline font handle from the admitted declaration" {
116     const allocator = std.testing.allocator;
117     var registry = try asset.Registry.init(allocator, .{ .fonts = 1, .images = 0, .owned_bytes = 0 });
118     defer registry.deinit(allocator);
119     registry.activate();
120     const face = try registry.registerFont("Fixture", .{}, .{ .borrowed = "" });
121     const declarations = [_]abi.Declaration{.{
122         .property = @backingInt(abi.PropertyId.font_family),
123         .kind = @backingInt(css.value.Kind.asset),
124         .unit = 0,
125         .flags = 0,
126         .a = face.index,
127         .b = face.generation,
128     }};
129     const nodes = [_]abi.Node{.{ .id = 1, .kind = @backingInt(abi.Kind.text), .declaration_count = 1 }};
130     const view = tree.View{ .nodes = &nodes, .declarations = &declarations };
131     const sheet = css.StyleSheet{};
132     var engine = try generation.Engine.init(allocator, .{ .nodes = 1, .distinct_styles = 2, .selectors = 1, .bytes = 16 * 1024 });
133     defer engine.deinit(allocator);
134     engine.activate();
135     try engine.setFonts(&registry);
136     _ = try engine.cascadeView(view, &.{0}, &sheet, 1, .{});
137     try std.testing.expectEqual(face, engine.record(0).text.face);
138 }
139 
140 test "style media environment filters sheets before cascade" {
141     const allocator = std.testing.allocator;
142     const source = "box { color: blue; } @media (prefers-color-scheme: dark) { box { color: red; } }";
143     var dark_workspace = css.Workspace.init(allocator);
144     defer dark_workspace.deinit();
145     var light_workspace = css.Workspace.init(allocator);
146     defer light_workspace.deinit();
147     const header = abi.Header{ .viewport = .{ .width = 1200, .height = 800 }, .root_font_size = 16 };
148     const dark = try (media.Environment.fromHeader(header, .dark, .no_preference)).parse(&dark_workspace, source);
149     const light = try (media.Environment.fromHeader(header, .light, .no_preference)).parse(&light_workspace, source);
150     const nodes = [_]abi.Node{.{ .id = 1, .kind = @backingInt(abi.Kind.box) }};
151     const view = tree.View{ .header = header, .nodes = &nodes };
152     var engine = try generation.Engine.init(allocator, .{ .nodes = 1, .distinct_styles = 4, .selectors = 4, .bytes = 16 * 1024 });
153     defer engine.deinit(allocator);
154     engine.activate();
155     _ = try engine.cascadeView(view, &.{0}, &dark, 1, .{});
156     try std.testing.expect(engine.record(0).paint.foreground.r > engine.record(0).paint.foreground.b);
157     _ = try engine.cascadeView(view, &.{}, &light, 2, .{});
158     try std.testing.expect(engine.record(0).paint.foreground.b > engine.record(0).paint.foreground.r);
159 }
160 
161 test "hover crossing two row boundaries restyles eighteen nodes" {
162     const allocator = std.testing.allocator;
163     var workspace = css.Workspace.init(allocator);
164     defer workspace.deinit();
165     const sheet = try workspace.parse(".row:hover .cell { color: #ff0000; }", .default());
166     var nodes: [128]abi.Node = undefined;
167     var classes: [18]u32 = undefined;
168     nodes[0] = .{ .id = 1, .subtree_count = 127 };
169     for (0..2) |row| {
170         const first = 1 + row * 9;
171         nodes[first] = .{
172             .id = @intCast(first + 1),
173             .parent = 0,
174             .subtree_count = 8,
175             .class_first = @intCast(row * 9),
176             .class_count = 1,
177         };
178         classes[row * 9] = 1;
179         for (0..8) |column| {
180             const at = first + column + 1;
181             nodes[at] = .{
182                 .id = @intCast(at + 1),
183                 .parent = @intCast(first),
184                 .class_first = @intCast(row * 9 + column + 1),
185                 .class_count = 1,
186             };
187             classes[row * 9 + column + 1] = 2;
188         }
189     }
190     for (19..nodes.len) |at| nodes[at] = .{ .id = @intCast(at + 1), .parent = 0 };
191     const atoms = [_]abi.Atom{ .{}, .{ .offset = 0, .len = 3 }, .{ .offset = 3, .len = 4 } };
192     const view = tree.View{
193         .header = .{ .root_font_size = 16 },
194         .nodes = &nodes,
195         .classes = &classes,
196         .atoms = &atoms,
197         .strings = "rowcell",
198     };
199     var engine = try @import("generation.zig").Engine.init(allocator, .{
200         .nodes = 128,
201         .distinct_styles = 8,
202         .selectors = 4,
203         .bytes = 64 * 1024,
204     });
205     defer engine.deinit(allocator);
206     engine.activate();
207     _ = try engine.cascadeView(view, &.{}, &sheet, 1, .{ .hovered = 2 });
208     const crossing = try engine.cascadeView(view, &.{}, &sheet, 1, .{ .hovered = 11 });
209     try std.testing.expectEqual(@as(u32, 18), crossing.restyled);
210     try std.testing.expectEqual(@as(u32, 18), crossing.visited);
211     engine.hover_filter_enabled = false;
212     const baseline = try engine.cascadeView(view, &.{}, &sheet, 1, .{ .hovered = 2 });
213     try std.testing.expectEqual(@as(u32, 128), baseline.restyled);
214     try std.testing.expectEqual(@as(u32, 128), baseline.visited);
215 }
216 
217 test "hover crossing visits eighteen nodes in a 16384 node tree" {
218     const allocator = std.testing.allocator;
219     var workspace = css.Workspace.init(allocator);
220     defer workspace.deinit();
221     const sheet = try workspace.parse(".row:hover .cell { color: #ff0000; }", .default());
222     const count = 16_384;
223     const nodes = try allocator.alloc(abi.Node, count);
224     defer allocator.free(nodes);
225     var classes: [18]u32 = undefined;
226     nodes[0] = .{ .id = 1, .subtree_count = count - 1 };
227     for (0..2) |row| {
228         const first = 1 + row * 9;
229         nodes[first] = .{
230             .id = @intCast(first + 1),
231             .parent = 0,
232             .subtree_count = 8,
233             .class_first = @intCast(row * 9),
234             .class_count = 1,
235         };
236         classes[row * 9] = 1;
237         for (0..8) |column| {
238             const at = first + column + 1;
239             nodes[at] = .{
240                 .id = @intCast(at + 1),
241                 .parent = @intCast(first),
242                 .class_first = @intCast(row * 9 + column + 1),
243                 .class_count = 1,
244             };
245             classes[row * 9 + column + 1] = 2;
246         }
247     }
248     for (19..count) |at| nodes[at] = .{ .id = @intCast(at + 1), .parent = 0 };
249     const atoms = [_]abi.Atom{ .{}, .{ .offset = 0, .len = 3 }, .{ .offset = 3, .len = 4 } };
250     const map_slots = try allocator.alloc(u32, 32_768);
251     defer allocator.free(map_slots);
252     var identity = tree.Map{ .slots = map_slots };
253     identity.reset();
254     for (nodes, 0..) |_, at| try std.testing.expect(identity.insert(nodes, @intCast(at)));
255     const view = tree.View{
256         .header = .{ .root_font_size = 16 },
257         .nodes = nodes,
258         .identity = &identity,
259         .classes = &classes,
260         .atoms = &atoms,
261         .strings = "rowcell",
262     };
263     var engine = try @import("generation.zig").Engine.init(allocator, .{});
264     defer engine.deinit(allocator);
265     engine.activate();
266     const full = try engine.cascadeView(view, &.{}, &sheet, 1, .{ .hovered = 2 });
267     try std.testing.expectEqual(@as(u32, count), full.visited);
268     const crossing = try engine.cascadeView(view, &.{}, &sheet, 1, .{ .hovered = 11 });
269     try std.testing.expectEqual(@as(u32, 18), crossing.restyled);
270     try std.testing.expectEqual(@as(u32, 18), crossing.visited);
271 }
272 
273 test "a 5000 row scroll carries survivors and visits only style inputs" {
274     const allocator = std.testing.allocator;
275     const count = 10_001;
276     const old_nodes = try allocator.alloc(abi.Node, count);
277     defer allocator.free(old_nodes);
278     const new_nodes = try allocator.alloc(abi.Node, count);
279     defer allocator.free(new_nodes);
280     const classes = try allocator.alloc(u32, count);
281     defer allocator.free(classes);
282     const prior = try allocator.alloc(u32, count);
283     defer allocator.free(prior);
284     old_nodes[0] = .{ .id = 1, .revision = 1, .subtree_count = count - 1 };
285     new_nodes[0] = .{ .id = 1, .revision = 2, .subtree_count = count - 1 };
286     prior[0] = tree.prior_dirty;
287     classes[0] = 0;
288     for (0..5_000) |row| {
289         const at = 1 + row * 2;
290         old_nodes[at] = .{ .id = @intCast(2 + row), .revision = 1, .parent = 0, .subtree_count = 1, .class_first = @intCast(at), .class_count = 1 };
291         old_nodes[at + 1] = .{ .id = @intCast(10_002 + row), .revision = 1, .parent = @intCast(at) };
292         new_nodes[at] = .{ .id = @intCast(3 + row), .revision = 1, .parent = 0, .subtree_count = 1, .class_first = @intCast(at), .class_count = 1 };
293         new_nodes[at + 1] = .{ .id = @intCast(10_003 + row), .revision = 1, .parent = @intCast(at) };
294         classes[at] = 1;
295         classes[at + 1] = 0;
296         prior[at] = if (row == 4_999) tree.prior_dirty | tree.prior_absent else @intCast(at + 2);
297         prior[at + 1] = if (row == 4_999) tree.prior_dirty | tree.prior_absent else @intCast(at + 3);
298     }
299     const atoms = [_]abi.Atom{ .{}, .{ .offset = 0, .len = 3 } };
300     const old_view = tree.View{ .header = .{ .revision = 1, .root_font_size = 16 }, .nodes = old_nodes, .classes = classes, .atoms = &atoms, .strings = "row" };
301     const new_view = tree.View{ .header = .{ .revision = 2, .base_revision = 1, .root_font_size = 16 }, .nodes = new_nodes, .classes = classes, .atoms = &atoms, .strings = "row", .prior = prior };
302     const dirty = [_]u32{ 0, 9_999, 10_000 };
303     var workspace = css.Workspace.init(allocator);
304     defer workspace.deinit();
305     const ordinary = try workspace.parse(".row { background-color: #102030; }", .default());
306     var engine = try @import("generation.zig").Engine.init(allocator, .{});
307     defer engine.deinit(allocator);
308     engine.activate();
309     _ = try engine.cascadeView(old_view, &.{}, &ordinary, 1, .{});
310     const moved = try engine.cascadeView(new_view, &dirty, &ordinary, 1, .{});
311     try std.testing.expectEqual(@as(u32, 2), moved.visited);
312     try std.testing.expectEqual(@as(u32, 2), moved.restyled);
313     try std.testing.expectEqual(@as(u32, 9_999), moved.carried);
314     try std.testing.expectEqual(@as(u64, 239_976), moved.carried_bytes);
315     var cold = try @import("generation.zig").Engine.init(allocator, .{});
316     defer cold.deinit(allocator);
317     cold.activate();
318     _ = try cold.cascadeView(new_view, &dirty, &ordinary, 1, .{});
319     for (0..count) |at| {
320         try std.testing.expect(std.meta.eql(engine.record(@intCast(at)).computed, cold.record(@intCast(at)).computed));
321     }
322     const positional = try workspace.parse(".row:nth-child(2n+1) { background-color: transparent; }", .default());
323     var positional_engine = try @import("generation.zig").Engine.init(allocator, .{});
324     defer positional_engine.deinit(allocator);
325     positional_engine.activate();
326     _ = try positional_engine.cascadeView(old_view, &.{}, &positional, 1, .{});
327     const shifted = try positional_engine.cascadeView(new_view, &dirty, &positional, 1, .{});
328     try std.testing.expectEqual(@as(u32, 5_001), shifted.visited);
329     try std.testing.expectEqual(@as(u32, 5_001), shifted.restyled);
330     try std.testing.expectEqual(@as(u32, 9_999), shifted.carried);
331     try std.testing.expectEqual(@as(u64, 239_976), shifted.carried_bytes);
332 }
333 
334 test "reparenting refreshes old and new sibling positions" {
335     const allocator = std.testing.allocator;
336     var workspace = css.Workspace.init(allocator);
337     defer workspace.deinit();
338     const sheet = try workspace.parse("box:nth-child(2) { color: #ff0000; }", .default());
339     const kind = @backingInt(abi.Kind.box);
340     const before = [_]abi.Node{
341         .{ .id = 1, .revision = 1, .kind = kind, .subtree_count = 5 },
342         .{ .id = 2, .revision = 1, .kind = kind, .parent = 0, .subtree_count = 3 },
343         .{ .id = 4, .revision = 1, .kind = kind, .parent = 1 },
344         .{ .id = 5, .revision = 1, .kind = kind, .parent = 1 },
345         .{ .id = 6, .revision = 1, .kind = kind, .parent = 1 },
346         .{ .id = 3, .revision = 1, .kind = kind, .parent = 0 },
347     };
348     const after = [_]abi.Node{
349         .{ .id = 1, .revision = 2, .kind = kind, .subtree_count = 5 },
350         .{ .id = 2, .revision = 2, .kind = kind, .parent = 0, .subtree_count = 2 },
351         .{ .id = 4, .revision = 1, .kind = kind, .parent = 1 },
352         .{ .id = 6, .revision = 1, .kind = kind, .parent = 1 },
353         .{ .id = 3, .revision = 2, .kind = kind, .parent = 0, .subtree_count = 1 },
354         .{ .id = 5, .revision = 1, .kind = kind, .parent = 4 },
355     };
356     const prior = [_]u32{ tree.prior_dirty, tree.prior_dirty | 1, 2, 4, tree.prior_dirty | 5, 3 };
357     var slots: [16]u32 = undefined;
358     var identity = tree.Map{ .slots = &slots };
359     identity.reset();
360     for (after, 0..) |_, at| try std.testing.expect(identity.insert(&after, @intCast(at)));
361     const old_view = tree.View{ .header = .{ .revision = 1, .root_font_size = 16 }, .nodes = &before };
362     const new_view = tree.View{ .header = .{ .revision = 2, .base_revision = 1, .root_font_size = 16 }, .nodes = &after, .identity = &identity, .prior = &prior };
363     const dirty = [_]u32{ 0, 1, 4 };
364     var engine = try @import("generation.zig").Engine.init(allocator, .{ .nodes = 6, .distinct_styles = 8, .selectors = 4, .bytes = 64 * 1024 });
365     defer engine.deinit(allocator);
366     engine.activate();
367     _ = try engine.cascadeView(old_view, &.{}, &sheet, 1, .{});
368     const old_color = engine.record(4).paint.foreground;
369     const moved = try engine.cascadeView(new_view, &dirty, &sheet, 1, .{});
370     try std.testing.expectEqual(@as(u32, 5), moved.visited);
371     try std.testing.expect(!std.meta.eql(old_color, engine.record(3).paint.foreground));
372     var cold = try @import("generation.zig").Engine.init(allocator, .{ .nodes = 6, .distinct_styles = 8, .selectors = 4, .bytes = 64 * 1024 });
373     defer cold.deinit(allocator);
374     cold.activate();
375     _ = try cold.cascadeView(new_view, &dirty, &sheet, 1, .{});
376     for (after, 0..) |_, at| {
377         try std.testing.expect(std.meta.eql(engine.record(@intCast(at)).computed, cold.record(@intCast(at)).computed));
378     }
379 }
380 
381 test "reparenting a hovered node updates both ancestor chains" {
382     const allocator = std.testing.allocator;
383     var workspace = css.Workspace.init(allocator);
384     defer workspace.deinit();
385     const sheet = try workspace.parse(".hot:hover .leaf { color: red; }", .default());
386     const before = [_]abi.Node{
387         .{ .id = 1, .revision = 1, .subtree_count = 5 },
388         .{ .id = 2, .revision = 1, .parent = 0, .subtree_count = 2, .class_first = 0, .class_count = 1 },
389         .{ .id = 10, .revision = 1, .parent = 1, .class_first = 1, .class_count = 1 },
390         .{ .id = 11, .revision = 1, .parent = 1, .class_first = 2, .class_count = 1 },
391         .{ .id = 3, .revision = 1, .parent = 0, .subtree_count = 1, .class_first = 3, .class_count = 1 },
392         .{ .id = 12, .revision = 1, .parent = 4, .class_first = 4, .class_count = 1 },
393     };
394     const after = [_]abi.Node{
395         .{ .id = 1, .revision = 2, .subtree_count = 5 },
396         .{ .id = 2, .revision = 2, .parent = 0, .subtree_count = 1, .class_first = 0, .class_count = 1 },
397         .{ .id = 11, .revision = 1, .parent = 1, .class_first = 1, .class_count = 1 },
398         .{ .id = 3, .revision = 2, .parent = 0, .subtree_count = 2, .class_first = 2, .class_count = 1 },
399         .{ .id = 10, .revision = 1, .parent = 3, .class_first = 3, .class_count = 1 },
400         .{ .id = 12, .revision = 1, .parent = 3, .class_first = 4, .class_count = 1 },
401     };
402     const before_classes = [_]u32{ 1, 2, 2, 1, 2 };
403     const after_classes = [_]u32{ 1, 2, 1, 2, 2 };
404     const atoms = [_]abi.Atom{ .{}, .{ .offset = 0, .len = 3 }, .{ .offset = 3, .len = 4 } };
405     const prior = [_]u32{ tree.prior_dirty, tree.prior_dirty | 1, 3, tree.prior_dirty | 4, 2, 5 };
406     var slots: [16]u32 = undefined;
407     var identity = tree.Map{ .slots = &slots };
408     identity.reset();
409     for (after, 0..) |_, at| try std.testing.expect(identity.insert(&after, @intCast(at)));
410     const old_view = tree.View{ .header = .{ .revision = 1, .root_font_size = 16 }, .nodes = &before, .classes = &before_classes, .atoms = &atoms, .strings = "hotleaf" };
411     const new_view = tree.View{ .header = .{ .revision = 2, .base_revision = 1, .root_font_size = 16 }, .nodes = &after, .classes = &after_classes, .atoms = &atoms, .strings = "hotleaf", .identity = &identity, .prior = &prior };
412     const dirty = [_]u32{ 0, 1, 3 };
413     var engine = try @import("generation.zig").Engine.init(allocator, .{ .nodes = 6, .distinct_styles = 8, .selectors = 4, .bytes = 64 * 1024 });
414     defer engine.deinit(allocator);
415     engine.activate();
416     const interaction = element.Interaction{ .hovered = 10 };
417     _ = try engine.cascadeView(old_view, &.{}, &sheet, 1, interaction);
418     const moved = try engine.cascadeView(new_view, &dirty, &sheet, 1, interaction);
419     try std.testing.expectEqual(@as(u32, 5), moved.visited);
420     var cold = try @import("generation.zig").Engine.init(allocator, .{ .nodes = 6, .distinct_styles = 8, .selectors = 4, .bytes = 64 * 1024 });
421     defer cold.deinit(allocator);
422     cold.activate();
423     _ = try cold.cascadeView(new_view, &dirty, &sheet, 1, interaction);
424     for (after, 0..) |_, at| {
425         try std.testing.expect(std.meta.eql(engine.record(@intCast(at)).computed, cold.record(@intCast(at)).computed));
426     }
427 }
428 
429 test "ancestor class invalidation walks descendants only for named classes" {
430     const allocator = std.testing.allocator;
431     var workspace = css.Workspace.init(allocator);
432     defer workspace.deinit();
433     const sheet = try workspace.parse(".row .cell { color: #ff0000; }", .default());
434     const atoms = [_]abi.Atom{
435         .{},
436         .{ .offset = 0, .len = 3 },
437         .{ .offset = 3, .len = 4 },
438         .{ .offset = 7, .len = 5 },
439         .{ .offset = 12, .len = 5 },
440     };
441     const nodes = [_]abi.Node{
442         .{ .id = 1, .subtree_count = 2, .class_first = 0, .class_count = 1 },
443         .{ .id = 2, .parent = 0, .class_first = 1, .class_count = 1 },
444         .{ .id = 3, .parent = 0, .class_first = 2, .class_count = 1 },
445     };
446     var classes = [_]u32{ 1, 2, 2 };
447     const view = tree.View{
448         .header = .{ .root_font_size = 16 },
449         .nodes = &nodes,
450         .classes = &classes,
451         .atoms = &atoms,
452         .strings = "rowcellotherextra",
453     };
454     var engine = try @import("generation.zig").Engine.init(allocator, .{
455         .nodes = 3,
456         .distinct_styles = 8,
457         .selectors = 4,
458         .bytes = 32 * 1024,
459     });
460     defer engine.deinit(allocator);
461     engine.activate();
462     _ = try engine.cascadeView(view, &.{}, &sheet, 1, .{});
463     classes[0] = 3;
464     const removed = try engine.cascadeView(view, &.{0}, &sheet, 1, .{});
465     try std.testing.expectEqual(@as(u32, 3), removed.restyled);
466     classes[0] = 4;
467     const unrelated = try engine.cascadeView(view, &.{0}, &sheet, 1, .{});
468     try std.testing.expectEqual(@as(u32, 1), unrelated.restyled);
469     classes[0] = 1;
470     const restored = try engine.cascadeView(view, &.{0}, &sheet, 1, .{});
471     try std.testing.expectEqual(@as(u32, 3), restored.restyled);
472 }
473 
474 test "default semantic chrome parses without diagnostics" {
475     var threaded: std.Io.Threaded = .init(std.testing.allocator, .{});
476     defer threaded.deinit();
477     const io = threaded.io();
478     var source: ?[]u8 = null;
479     for ([_][]const u8{ "lib/ui/assets/css/default.css", "assets/css/default.css" }) |path| {
480         source = std.Io.Dir.cwd().readFileAlloc(io, path, std.testing.allocator, .limited(64 * 1024)) catch continue;
481         break;
482     }
483     const css_source = source orelse return error.DefaultCssMissing;
484     defer std.testing.allocator.free(css_source);
485     var workspace = css.Workspace.init(std.testing.allocator);
486     defer workspace.deinit();
487     const sheet = try workspace.parse(css_source, .default());
488     try std.testing.expectEqual(@as(usize, 0), sheet.diagnostics.len);
489     try std.testing.expect(sheet.rules.len >= 7);
490     const nodes = [_]abi.Node{
491         .{ .id = 1, .subtree_count = 1 },
492         .{ .id = 2, .parent = 0, .role = @backingInt(abi.Role.button), .state = abi.state(.selected) },
493     };
494     var engine = try @import("generation.zig").Engine.init(std.testing.allocator, .{
495         .nodes = 2,
496         .distinct_styles = 8,
497         .selectors = 64,
498         .bytes = 64 * 1024,
499     });
500     defer engine.deinit(std.testing.allocator);
501     engine.activate();
502     _ = try engine.cascadeView(.{ .nodes = &nodes }, &.{}, &sheet, 1, .{ .focused = 2, .keyboard_focus = true });
503     const button = engine.record(1);
504     try std.testing.expect(button.paint.background.a != 0);
505     try std.testing.expectEqual(@as(f32, 4), button.paint.radius[0]);
506     try std.testing.expectEqual(@as(f32, 4), button.paint.outset);
507 }
508 
509 test "stylesheet generation selects bucket keys and agrees with a cold cascade" {
510     const allocator = std.testing.allocator;
511     var first_workspace = css.Workspace.init(allocator);
512     defer first_workspace.deinit();
513     var second_workspace = css.Workspace.init(allocator);
514     defer second_workspace.deinit();
515     const first = try first_workspace.parse(".alpha { color: red; }", .default());
516     const second = try second_workspace.parse(".beta { color: blue; }", .default());
517     const nodes = [_]abi.Node{
518         .{ .id = 1, .subtree_count = 3 },
519         .{ .id = 2, .parent = 0, .class_first = 0, .class_count = 1 },
520         .{ .id = 3, .parent = 0, .class_first = 1, .class_count = 1 },
521         .{ .id = 4, .parent = 0, .class_first = 2, .class_count = 1 },
522     };
523     const atoms = [_]abi.Atom{ .{}, .{ .offset = 0, .len = 5 }, .{ .offset = 5, .len = 4 }, .{ .offset = 9, .len = 5 } };
524     const classes = [_]u32{ 1, 2, 3 };
525     const view = tree.View{ .nodes = &nodes, .classes = &classes, .atoms = &atoms, .strings = "alphabetagamma" };
526     const limits = @import("generation.zig").Limits{ .nodes = 4, .distinct_styles = 8, .selectors = 4, .bytes = 32 * 1024 };
527     var incremental = try @import("generation.zig").Engine.init(allocator, limits);
528     defer incremental.deinit(allocator);
529     incremental.activate();
530     _ = try incremental.cascadeView(view, &.{}, &first, 1, .{});
531     const changed = try incremental.cascadeView(view, &.{}, &second, 2, .{});
532     try std.testing.expectEqual(@as(u32, 2), changed.restyled);
533     var cold = try @import("generation.zig").Engine.init(allocator, limits);
534     defer cold.deinit(allocator);
535     cold.activate();
536     _ = try cold.cascadeView(view, &.{}, &second, 2, .{});
537     for (nodes, 0..) |_, at| try std.testing.expect(std.meta.eql(incremental.record(@intCast(at)).*, cold.record(@intCast(at)).*));
538 }
539 
540 test "focus visible begins with keyboard focus and clears for pointer focus" {
541     const allocator = std.testing.allocator;
542     var workspace = css.Workspace.init(allocator);
543     defer workspace.deinit();
544     const sheet = try workspace.parse(":focus-visible { color: #ff0000; }", .default());
545     const nodes = [_]abi.Node{ .{ .id = 1, .subtree_count = 1 }, .{ .id = 2, .parent = 0 } };
546     const view = tree.View{ .nodes = &nodes };
547     var engine = try @import("generation.zig").Engine.init(allocator, .{ .nodes = 2, .distinct_styles = 4, .selectors = 2, .bytes = 16 * 1024 });
548     defer engine.deinit(allocator);
549     engine.activate();
550     _ = try engine.cascadeView(view, &.{}, &sheet, 1, .{ .focused = 2 });
551     const pointer = engine.record(1).paint.foreground;
552     const keyboard = try engine.cascadeView(view, &.{}, &sheet, 1, .{ .focused = 2, .keyboard_focus = true });
553     try std.testing.expect(keyboard.restyled > 0);
554     try std.testing.expect(!std.meta.eql(pointer, engine.record(1).paint.foreground));
555     const steady = try engine.cascadeView(view, &.{}, &sheet, 1, .{ .focused = 2, .keyboard_focus = true });
556     try std.testing.expectEqual(@as(u32, 0), steady.restyled);
557     _ = try engine.cascadeView(view, &.{}, &sheet, 1, .{ .focused = 2 });
558     try std.testing.expect(std.meta.eql(pointer, engine.record(1).paint.foreground));
559 }
560 
561 test "focus from parent to child clears the parent direct focus" {
562     const allocator = std.testing.allocator;
563     var workspace = css.Workspace.init(allocator);
564     defer workspace.deinit();
565     const sheet = try workspace.parse(":focus { color: red; } :focus-visible { background: blue; } :focus-within { border-color: green; }", .default());
566     const nodes = [_]abi.Node{ .{ .id = 1, .subtree_count = 1 }, .{ .id = 2, .parent = 0 } };
567     const view = tree.View{ .nodes = &nodes };
568     const limits = @import("generation.zig").Limits{ .nodes = 2, .distinct_styles = 8, .selectors = 4, .bytes = 64 * 1024 };
569     var incremental = try @import("generation.zig").Engine.init(allocator, limits);
570     defer incremental.deinit(allocator);
571     incremental.activate();
572     _ = try incremental.cascadeView(view, &.{}, &sheet, 1, .{ .focused = 1, .keyboard_focus = true });
573     const changed = try incremental.cascadeView(view, &.{}, &sheet, 1, .{ .focused = 2 });
574     try std.testing.expectEqual(@as(u32, 2), changed.visited);
575     var cold = try @import("generation.zig").Engine.init(allocator, limits);
576     defer cold.deinit(allocator);
577     cold.activate();
578     _ = try cold.cascadeView(view, &.{}, &sheet, 1, .{ .focused = 2 });
579     for (nodes, 0..) |_, at| try std.testing.expect(std.meta.eql(incremental.record(@intCast(at)).*, cold.record(@intCast(at)).*));
580 }
581 
582 test "hover invalidation covers ancestor kind selectors" {
583     const allocator = std.testing.allocator;
584     var workspace = css.Workspace.init(allocator);
585     defer workspace.deinit();
586     const sheet = try workspace.parse("box:hover text { color: #ff0000; }", .default());
587     const nodes = [_]abi.Node{
588         .{ .id = 1, .kind = @backingInt(abi.Kind.box), .subtree_count = 1 },
589         .{ .id = 2, .kind = @backingInt(abi.Kind.text), .parent = 0 },
590     };
591     const view = tree.View{ .nodes = &nodes };
592     var engine = try @import("generation.zig").Engine.init(allocator, .{ .nodes = 2, .distinct_styles = 4, .selectors = 2, .bytes = 16 * 1024 });
593     defer engine.deinit(allocator);
594     engine.activate();
595     _ = try engine.cascadeView(view, &.{}, &sheet, 1, .{});
596     const before = engine.record(1).paint.foreground;
597     const entered = try engine.cascadeView(view, &.{}, &sheet, 1, .{ .hovered = 2 });
598     try std.testing.expectEqual(@as(u32, 2), entered.restyled);
599     try std.testing.expect(!std.meta.eql(before, engine.record(1).paint.foreground));
600     const left = try engine.cascadeView(view, &.{}, &sheet, 1, .{});
601     try std.testing.expectEqual(@as(u32, 2), left.restyled);
602     try std.testing.expect(std.meta.eql(before, engine.record(1).paint.foreground));
603 }
604 
605 test "stylesheet change refreshes hover sensitivity of copied ancestors" {
606     const allocator = std.testing.allocator;
607     var first_workspace = css.Workspace.init(allocator);
608     defer first_workspace.deinit();
609     var second_workspace = css.Workspace.init(allocator);
610     defer second_workspace.deinit();
611     const first = try first_workspace.parse(".beta { color: #0000ff; }", .default());
612     const second = try second_workspace.parse(".alpha:hover .beta { color: #ff0000; }", .default());
613     const nodes = [_]abi.Node{
614         .{ .id = 1, .subtree_count = 1, .class_first = 0, .class_count = 1 },
615         .{ .id = 2, .parent = 0, .class_first = 1, .class_count = 1 },
616     };
617     const atoms = [_]abi.Atom{ .{}, .{ .offset = 0, .len = 5 }, .{ .offset = 5, .len = 4 } };
618     const classes = [_]u32{ 1, 2 };
619     const view = tree.View{ .nodes = &nodes, .classes = &classes, .atoms = &atoms, .strings = "alphabeta" };
620     var engine = try @import("generation.zig").Engine.init(allocator, .{ .nodes = 2, .distinct_styles = 4, .selectors = 2, .bytes = 16 * 1024 });
621     defer engine.deinit(allocator);
622     engine.activate();
623     _ = try engine.cascadeView(view, &.{}, &first, 1, .{});
624     _ = try engine.cascadeView(view, &.{}, &second, 2, .{});
625     const before = engine.record(1).paint.foreground;
626     const entered = try engine.cascadeView(view, &.{}, &second, 2, .{ .hovered = 2 });
627     try std.testing.expectEqual(@as(u32, 2), entered.restyled);
628     try std.testing.expect(!std.meta.eql(before, engine.record(1).paint.foreground));
629 }
630 
631 test "inherited variables distinguish children of otherwise shared parents" {
632     const allocator = std.testing.allocator;
633     var workspace = css.Workspace.init(allocator);
634     defer workspace.deinit();
635     const sheet = try workspace.parse(
636         ".red { --ink: #ff0000; } .blue { --ink: #0000ff; } .child { color: var(--ink); }",
637         .default(),
638     );
639     try std.testing.expectEqual(@as(usize, 0), sheet.diagnostics.len);
640     const nodes = [_]abi.Node{
641         .{ .id = 1, .subtree_count = 4 },
642         .{ .id = 2, .parent = 0, .subtree_count = 1, .class_first = 0, .class_count = 1 },
643         .{ .id = 3, .parent = 1, .class_first = 1, .class_count = 1 },
644         .{ .id = 4, .parent = 0, .subtree_count = 1, .class_first = 2, .class_count = 1 },
645         .{ .id = 5, .parent = 3, .class_first = 3, .class_count = 1 },
646     };
647     const atoms = [_]abi.Atom{ .{}, .{ .offset = 0, .len = 3 }, .{ .offset = 3, .len = 5 }, .{ .offset = 8, .len = 4 } };
648     var classes = [_]u32{ 1, 2, 3, 2 };
649     const view = tree.View{ .nodes = &nodes, .classes = &classes, .atoms = &atoms, .strings = "redchildblue" };
650     var engine = try @import("generation.zig").Engine.init(allocator, .{ .nodes = 5, .distinct_styles = 8, .selectors = 8, .bytes = 32 * 1024 });
651     defer engine.deinit(allocator);
652     engine.activate();
653     _ = try engine.cascadeView(view, &.{}, &sheet, 1, .{});
654     try std.testing.expect(engine.record(1) == engine.record(3));
655     try std.testing.expect(engine.record(2) != engine.record(4));
656     const before = engine.record(2).paint.foreground;
657     classes[0] = 3;
658     const changed = try engine.cascadeView(view, &.{1}, &sheet, 1, .{});
659     try std.testing.expectEqual(@as(u32, 5), changed.restyled);
660     try std.testing.expect(!std.meta.eql(before, engine.record(2).paint.foreground));
661     try std.testing.expect(std.meta.eql(engine.record(2).paint.foreground, engine.record(4).paint.foreground));
662 }