Improve error messages.

gen/Content.elm

@@ -52,11 +52,19 @@ allData =
                         , pages = successPageListings
                         }
 
-                Err _ ->
-                    Err (Element.text "Error... TODO give more details")
+                Err errors ->
+                    Err (renderErrors errors)
 
-        Err errorErrorMarkList ->
-            Err (Element.text "Error... TODO give more details")
+        Err errors ->
+            Err (renderErrors errors)
+
+
+renderErrors : List Mark.Error.Error -> Element msg
+renderErrors errors =
+    errors
+        |> List.map (Mark.Error.toHtml Mark.Error.Light)
+        |> List.map Element.html
+        |> Element.column []
 
 
 pages : List ( List String, String )
@@ -219,6 +227,15 @@ Morbi ut porta justo. Integer ac eleifend sem. Fusce sed auctor velit, et condim
     This is a code block
     With Multiple lines
 
+|> H1
+    Articles
+
+
+|> IndexContent
+    posts = articles
+
+Here are a few articles you might like.
+
 |> H1
     My section on /lists/
 

src/MarkParser.elm

@@ -239,7 +239,20 @@ indexContent content =
         (\postsPath ->
             content
         )
-        |> Mark.field "posts" Mark.string
+        |> Mark.field "posts"
+            (Mark.string
+                |> Mark.verify
+                    (\postDirectory ->
+                        if postDirectory == "articles" then
+                            Ok "articles"
+
+                        else
+                            Err
+                                { title = "Could not find posts path `" ++ postDirectory ++ "`"
+                                , message = "Must be one of " :: [ "articles" ]
+                                }
+                    )
+            )
         |> Mark.toBlock