Add comprehensive WebGL.Texture test validation for both success and error cases

Co-authored-by: supermario <102781+supermario@users.noreply.github.com>

Author: Copilot

test/Test.hs

@@ -21,11 +21,8 @@ import qualified Test.Ext.ElmPages.Check
 import qualified Test.TypeHashes
 import qualified Test.JsOutput
 import qualified Test.WebGL
-<<<<<<< HEAD
 import qualified Test.Lamdera.Live
-=======
 import qualified Test.BackwardsCompat
->>>>>>> bdcb71f7 (Test Lamdera HTML injections don't happen on vanilla Elm projects)
 
 import qualified Test.Lamdera.Evergreen.TestMigrationHarness
 import qualified Test.Lamdera.Evergreen.TestMigrationGenerator

test/Test/WebGL.hs

@@ -46,4 +46,14 @@ suite = tests
         actual <- catchOutput $ Lamdera.Compile.makeDev project [ "src/Frontend.elm", "src/Backend.elm", "src/Types.elm" ]
 
         expectTextContains actual "Success! Compiled 3 modules."
+
+  , scope "compilation should fail with WebGL.Texture in backend contexts" $ do
+        project <- io $ Lamdera.Relative.requireDir "test/scenario-webgl-texture"
+
+        _ <- io $ rmdir (project </> "elm-stuff")
+
+        actual <- catchOutput $ Lamdera.Compile.makeDev project [ "src/TestBadWebGL.elm" ]
+
+        -- Should fail with kernel error for browser-only types
+        expectTextContains actual "can only be used in the frontend"
   ]

test/scenario-webgl-texture/src/TestBadWebGL.elm

@@ -0,0 +1,13 @@
+module TestBadWebGL exposing (..)
+
+-- This should fail compilation because WebGL.Texture is in ToBackend
+import WebGL.Texture as Texture
+
+
+type ToBackend
+    = SendTexture Texture.Texture  -- This should cause an error
+
+
+type alias BackendModel =
+    { texture : Maybe Texture.Texture  -- This should also cause an error
+    }