Make FatalError opaque.

examples/end-to-end/script/src/Stars.elm

@@ -20,7 +20,7 @@ run =
                     (\stars ->
                         Script.log (String.fromInt stars)
                     )
-                |> BackendTask.throw
+                |> BackendTask.allowFatal
         )
 
 

src/BackendTask/Env.elm

@@ -75,7 +75,7 @@ expect envVariableName =
             (\maybeValue ->
                 maybeValue
                     |> Result.fromMaybe
-                        { fatal =
+                        (FatalError.recoverable
                             { title = "Missing Env Variable"
                             , body =
                                 [ TerminalText.text "BackendTask.Env.expect was expecting a variable `"
@@ -84,7 +84,7 @@ expect envVariableName =
                                 ]
                                     |> TerminalText.toString
                             }
-                        , recoverable = MissingEnvVariable envVariableName
+                            (MissingEnvVariable envVariableName)
-                        }
+                        )
                     |> BackendTask.fromResult
             )

src/BackendTask/File.elm

@@ -326,15 +326,14 @@ jsonFile jsonFileDecoder filePath =
                     |> Decode.decodeString jsonFileDecoder
                     |> Result.mapError
                         (\jsonDecodeError ->
-                            { fatal =
+                            FatalError.recoverable
                                 { title = "JSON Decoding Error"
                                 , body =
                                     [ TerminalText.text (Decode.errorToString jsonDecodeError)
                                     ]
                                         |> TerminalText.toString
                                 }
-                            , recoverable = DecodingError jsonDecodeError
+                                (DecodingError jsonDecodeError)
-                            }
                         )
                     |> BackendTask.fromResult
             )
@@ -372,7 +371,7 @@ errorDecoder :
             }
 errorDecoder filePath =
     Decode.succeed
-        { fatal =
+        (FatalError.recoverable
             { title = "File Doesn't Exist"
             , body =
                 [ TerminalText.text "Couldn't find file at path `"
@@ -381,5 +380,5 @@ errorDecoder filePath =
                 ]
                     |> TerminalText.toString
             }
-        , recoverable = FileDoesntExist
+            FileDoesntExist
-        }
+        )

src/BackendTask/Glob.elm

@@ -1066,14 +1066,14 @@ expectUniqueMatch glob =
 
                     [] ->
                         BackendTask.fail <|
-                            FatalError.fromStringWithValue
+                            FatalError.recoverable
-                                ("No files matched the pattern: " ++ toPatternString glob)
+                                { title = "Non-Unique Glob", body = "No files matched the pattern: " ++ toPatternString glob }
                                 ("No files matched the pattern: " ++ toPatternString glob)
 
                     _ ->
                         BackendTask.fail <|
-                            FatalError.fromStringWithValue
+                            FatalError.recoverable
-                                "More than one file matched."
+                                { title = "Non-Unique Glob", body = "Expected a unique match, but more than one file matched." }
                                 "More than one file matched."
             )
 

src/BackendTask/Http.elm

@@ -573,7 +573,7 @@ requestRaw request__ expect =
                 |> BackendTask.fromResult
                 |> BackendTask.mapError
                     (\error ->
-                        FatalError.Recoverable (errorToString error) error
+                        FatalError.recoverable (errorToString error) error
                     )
         )
 

src/BackendTask/Port.elm

@@ -105,7 +105,7 @@ get portName input decoder =
                     |> Decode.andThen
                         (\errorKind ->
                             if errorKind == "PortNotDefined" then
-                                { fatal =
+                                FatalError.recoverable
                                     { title = "Port Error"
                                     , body =
                                         [ TerminalText.text "Something went wrong in a call to BackendTask.Port.get. I expected to find a port named `"
@@ -114,8 +114,7 @@ get portName input decoder =
                                         ]
                                             |> TerminalText.toString
                                     }
-                                , recoverable = PortNotDefined { name = portName }
+                                    (PortNotDefined { name = portName })
-                                }
                                     |> Decode.succeed
 
                             else if errorKind == "ExportIsNotFunction" then
@@ -124,7 +123,7 @@ get portName input decoder =
                                     |> Decode.map (Maybe.withDefault "")
                                     |> Decode.map
                                         (\incorrectPortType ->
-                                            FatalError.Recoverable
+                                            FatalError.recoverable
                                                 { title = "Port Error"
                                                 , body =
                                                     [ TerminalText.text "Something went wrong in a call to BackendTask.Port.get. I found an export called `"
@@ -138,7 +137,7 @@ get portName input decoder =
                                         )
 
                             else if errorKind == "MissingPortsFile" then
-                                FatalError.Recoverable
+                                FatalError.recoverable
                                     { title = "Port Error"
                                     , body =
                                         [ TerminalText.text "Something went wrong in a call to BackendTask.Port.get. I couldn't find your port-data-source file. Be sure to create a 'port-data-source.ts' or 'port-data-source.js' file."
@@ -154,7 +153,7 @@ get portName input decoder =
                                     |> Decode.map (Maybe.withDefault "")
                                     |> Decode.map
                                         (\errorMessage ->
-                                            FatalError.Recoverable
+                                            FatalError.recoverable
                                                 { title = "Port Error"
                                                 , body =
                                                     [ TerminalText.text "Something went wrong in a call to BackendTask.Port.get. I couldn't import the port definitions file, because of this exception:\n\n"
@@ -172,7 +171,7 @@ get portName input decoder =
                                     |> Decode.map (Maybe.withDefault Encode.null)
                                     |> Decode.map
                                         (\portCallError ->
-                                            FatalError.Recoverable
+                                            FatalError.recoverable
                                                 { title = "Port Error"
                                                 , body =
                                                     [ TerminalText.text "Something went wrong in a call to BackendTask.Port.get. I was able to import the port definitions file, but when running it I encountered this exception:\n\n"
@@ -185,7 +184,7 @@ get portName input decoder =
                                         )
 
                             else
-                                FatalError.Recoverable
+                                FatalError.recoverable
                                     { title = "Port Error"
                                     , body =
                                         [ TerminalText.text "Something went wrong in a call to BackendTask.Port.get. I expected to find a port named `"

src/FatalError.elm

@@ -1,5 +1,5 @@
 module FatalError exposing
-    ( FatalError, fromString, fromStringWithValue
+    ( FatalError, fromString, recoverable
     , Recoverable
     )
 
@@ -57,12 +57,14 @@ issue.
 In the case of server-rendered Routes (`RouteBuilder.serverRender`), `elm-pages` will show your 500 error page
 when these errors occur.
 
-@docs FatalError, fromString, fromStringWithValue
+@docs FatalError, fromString, recoverable
 
 @docs Recoverable
 
 -}
 
+import Pages.Internal.FatalError
+
 
 {-| -}
 type alias Recoverable error =
@@ -73,20 +75,27 @@ type alias Recoverable error =
 
 {-| -}
 type alias FatalError =
-    { title : String, body : String }
+    Pages.Internal.FatalError.FatalError
+
+
+{-| -}
+build : { title : String, body : String } -> FatalError
+build info =
+    Pages.Internal.FatalError.FatalError info
 
 
 {-| -}
 fromString : String -> FatalError
 fromString string =
-    { title = "Custom Error"
+    build
-    , body = string
+        { title = "Custom Error"
-    }
+        , body = string
+        }
 
 
 {-| -}
-fromStringWithValue : String -> value -> Recoverable value
+recoverable : { title : String, body : String } -> value -> Recoverable value
-fromStringWithValue string value =
+recoverable info value =
-    { fatal = { title = "Custom Error", body = string }
+    { fatal = build info
     , recoverable = value
     }

src/Pages/Internal/FatalError.elm

@@ -0,0 +1,5 @@
+module Pages.Internal.FatalError exposing (FatalError(..))
+
+
+type FatalError
+    = FatalError { title : String, body : String }

src/Pages/Internal/Platform/StaticResponses.elm

@@ -4,6 +4,7 @@ import BackendTask exposing (BackendTask)
 import BuildError exposing (BuildError)
 import FatalError exposing (FatalError, Recoverable)
 import List.Extra
+import Pages.Internal.FatalError
 import Pages.StaticHttp.Request as HashRequest
 import Pages.StaticHttpRequest as StaticHttpRequest
 import RequestsAndPending exposing (RequestsAndPending)
@@ -111,7 +112,7 @@ nextStep allRawResponses staticResponses { errors } =
                 Just (Ok completed) ->
                     Finish completed
 
-                Just (Err buildError) ->
+                Just (Err (Pages.Internal.FatalError.FatalError buildError)) ->
                     FinishedWithErrors
                         [ { title = buildError.title |> String.toUpper
                           , path = "" -- TODO include path here