animate anchored theme colors on native and tty backends

1 files changed, 15 insertions, 2 deletions

diff --git a/test/snapshot.zig b/test/snapshot.zig
index 7c00b97c..0a2b299d 100644
--- a/test/snapshot.zig
+++ b/test/snapshot.zig
@@ -617,12 +617,25 @@ fn readProc(buf: []u8, path: [*:0]const u8) ?[]const u8 {
     return buf[0..@intCast(got)];
 }
 
-/// What a `snap` capture is made of: the grid text plus the cursor cell.
+/// What a capture is made of: grid text, cursor cell, and a compact digest of
+/// every cell style. Style used not to matter to `stable`, which let a
+/// color-only animation look idle while the TTY frontend was deliberately
+/// asleep between frames; a following `snapstyle` then caught a midpoint.
 fn stateKey(h: *eh.Harness) ![]u8 {
     const text = try h.screenText();
     defer h.gpa.free(text);
     const c = h.cursor();
-    return std.fmt.allocPrint(h.gpa, "{d},{d}\n{s}", .{ c.x, c.y, text });
+    var styles = std.hash.Wyhash.init(0x5354_594c_4553_2121);
+    var y: u16 = 0;
+    while (y < h.rows) : (y += 1) {
+        var x: u16 = 0;
+        while (x < h.cols) : (x += 1) {
+            var key_buf: [64]u8 = undefined;
+            styles.update(cellKey(h, x, y, &key_buf));
+            styles.update("\x00");
+        }
+    }
+    return std.fmt.allocPrint(h.gpa, "{d},{d},{x}\n{s}", .{ c.x, c.y, styles.final(), text });
 }
 
 fn snapText(arena: std.mem.Allocator, out: *std.ArrayList(u8), h: *eh.Harness, label: []const u8) !void {