make lesson modules more fail proof

views/mixins/_lesson.pug

@@ -9,6 +9,7 @@ mixin lesson(lesson)
     if lesson.fields.image
       img.lesson__image(src=`${lesson.fields.image.fields.file.url}` alt=`${lesson.fields.image.fields.title}`)
     each module in lesson.fields.modules
+      if module.sys.contentType
         case module.sys.contentType.sys.id
           when 'lessonModuleCodeSnippets'
             +lessonModuleCodeSnippet(module)
@@ -16,3 +17,8 @@ mixin lesson(lesson)
             +lessonModuleCopy(module)
           when 'lessonModuleImage'
             +lessonModuleImage(module)
+      else
+        h2 ️️⚠️ Invalid lesson module
+        p
+          span Could not determine type of
+          strong  #{module.sys.id}

views/mixins/_lessonModuleImage.pug

@@ -1,4 +1,7 @@
 mixin lessonModuleImage(module)
   .lesson-module.lesson-module-image
+    h2.lesson-module-image__title #{module.fields.title}
+    if module.fields.file && module.fields.file.url
       img.lesson-module-image__image(src=module.fields.file.url alt=module.fields.title)
-    div.lesson-module-image__title #{module.fields.title}
+    else
+      h3 ⚠️ Image missing