add(test): container size with fixed and growable container children

src/container.zig

@@ -904,3 +904,51 @@ test {
     _ = Layout;
     _ = Rectangle;
 }
+
+test "Container Fixed and Grow Size Vertical" {
+    const event = @import("event.zig");
+    const testing = @import("testing.zig");
+
+    var container: Container(event.SystemEvent) = try .init(std.testing.allocator, .{
+        .layout = .{ .direction = .vertical },
+    }, .{});
+    try container.append(try .init(std.testing.allocator, .{
+        .size = .{
+            .dim = .{ .y = 5 },
+            .grow = .horizontal,
+        },
+        .rectangle = .{ .fill = .grey },
+    }, .{}));
+    try container.append(try .init(std.testing.allocator, .{
+        .rectangle = .{ .fill = .red },
+    }, .{}));
+    defer container.deinit();
+
+    try testing.expectContainerScreen(.{
+        .y = 20,
+        .x = 30,
+    }, &container, @import("test/container/fixed_grow_vertical.zon"));
+}
+
+test "Container Fixed and Grow Size Horizontal" {
+    const event = @import("event.zig");
+    const testing = @import("testing.zig");
+
+    var container: Container(event.SystemEvent) = try .init(std.testing.allocator, .{}, .{});
+    try container.append(try .init(std.testing.allocator, .{
+        .size = .{
+            .dim = .{ .x = 5 },
+            .grow = .vertical,
+        },
+        .rectangle = .{ .fill = .grey },
+    }, .{}));
+    try container.append(try .init(std.testing.allocator, .{
+        .rectangle = .{ .fill = .red },
+    }, .{}));
+    defer container.deinit();
+
+    try testing.expectContainerScreen(.{
+        .y = 20,
+        .x = 30,
+    }, &container, @import("test/container/fixed_grow_horizontal.zon"));
+}