test: check grid maths on both real screen sizes

The grid's justification is that one layout table works on differently
shaped screens, so assert it: every cell lands inside the margins at
2560x1080 and 1920x1080, a spanning cell absorbs the gap it covers, and
no shipped layout entry falls outside the declared grid.

dashboard.lua exports its internals for this; cairo and lib.card are
stubbed via package.preload since they only exist inside Conky.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/dashboard.lua b/dashboard.lua
index b814be7..af6e51c 100644
--- a/dashboard.lua
+++ b/dashboard.lua
@@ -95,6 +95,11 @@ local function rect_for(entry, sw, sh)
   }
 end
 
+-- Exported for test/test_layout.lua. The grid's whole claim is that one layout
+-- table works on differently shaped screens, which is worth checking.
+conky_dashboard_internal = { rect_for = rect_for, COLS = COLS, ROWS = ROWS,
+                             GAP = GAP, MARGIN = MARGIN, layout = layout }
+
 -- Widget modules, loaded once and cached. A widget that fails to load must not
 -- take the frame down with it, so the require is wrapped.
 local widgets = {}