diff --git a/src/Scope.elm b/src/Scope.elm
index 977818d1..536040b5 100644
--- a/src/Scope.elm
+++ b/src/Scope.elm
@@ -68,6 +68,9 @@ initialContext =
     Context
         { scopes = Nonempty.fromElement Dict.empty
         , importAliases = Dict.empty
+
+        -- TODO Add elm/core's prelude
+        -- https://package.elm-lang.org/packages/elm/core/latest
         , importedFunctionOrTypes = Dict.empty
         , dependencies = Dict.empty
         }
diff --git a/tests/Dependencies.elm b/tests/Dependencies.elm
new file mode 100644
index 00000000..668618d8
--- /dev/null
+++ b/tests/Dependencies.elm
@@ -0,0 +1,31 @@
+module Dependencies exposing (elmHtml)
+
+import Elm.Docs
+import Elm.Type as Type
+
+
+elmHtml : { packageName : String, modules : List Elm.Docs.Module }
+elmHtml =
+    { packageName = "elm/html"
+    , modules =
+        [ { name = "Html"
+          , comment = ""
+          , unions = []
+          , aliases = []
+          , values =
+                [ { name = "button"
+                  , comment = ""
+                  , tipe =
+                        -- List.List (Html.Attribute msg) ->
+                        Type.Lambda (Type.Type "List.List" [ Type.Type "Html.Attribute" [ Type.Var "msg" ] ])
+                            --  List.List (Html.Html msg) ->
+                            (Type.Lambda (Type.Type "List.List" [ Type.Type "Html.Html" [ Type.Var "msg" ] ])
+                                -- Html.Html msg
+                                (Type.Type "Html.Html" [ Type.Var "msg" ])
+                            )
+                  }
+                ]
+          , binops = []
+          }
+        ]
+    }
diff --git a/tests/NoHtmlButtonTest.elm b/tests/NoHtmlButtonTest.elm
index c0f868c0..2a03b666 100644
--- a/tests/NoHtmlButtonTest.elm
+++ b/tests/NoHtmlButtonTest.elm
@@ -1,5 +1,6 @@
 module NoHtmlButtonTest exposing (all)
 
+import Dependencies
 import Elm.Type as Type
 import NoHtmlButton exposing (rule)
 import Review.Project as Project exposing (Project)
@@ -17,26 +18,7 @@ testRule string =
 projectWithHtmlDependency : Project
 projectWithHtmlDependency =
     Project.new
-        |> Project.withDependency
-            { packageName = "elm/html"
-            , modules =
-                [ { name = "Html"
-                  , comment = ""
-                  , unions = []
-                  , aliases = []
-                  , values =
-                        [ { name = "button"
-                          , comment = ""
-                          , tipe =
-                                -- "List.List (Html.Attribute msg) -> List.List (Html.Html msg) -> Html.Html msg"
-                                Type.Lambda (Type.Type "List.List" [ Type.Type "Html.Attribute" [ Type.Var "msg" ] ])
-                                    (Type.Lambda (Type.Type "List.List" [ Type.Type "Html.Html" [ Type.Var "msg" ] ]) (Type.Type "Html.Html" [ Type.Var "msg" ]))
-                          }
-                        ]
-                  , binops = []
-                  }
-                ]
-            }
+        |> Project.withDependency Dependencies.elmHtml
 
 
 testRuleWithHtmlDependency : String -> ReviewResult
diff --git a/tests/ScopeTest.elm b/tests/ScopeTest.elm
new file mode 100644
index 00000000..0e017be3
--- /dev/null
+++ b/tests/ScopeTest.elm
@@ -0,0 +1,132 @@
+module ScopeTest exposing (all)
+
+import Dependencies
+import Elm.Syntax.Declaration exposing (Declaration)
+import Elm.Syntax.Expression as Expression exposing (Expression)
+import Elm.Syntax.Node as Node exposing (Node)
+import Review.Project as Project exposing (Project)
+import Review.Rule as Rule exposing (Rule)
+import Review.Test exposing (ReviewResult)
+import Scope
+import Test exposing (Test, test)
+
+
+type alias Context =
+    { scope : Scope.Context
+    , text : String
+    }
+
+
+project : Project
+project =
+    Project.new
+        |> Project.withDependency Dependencies.elmHtml
+
+
+testRule : Rule -> String -> ReviewResult
+testRule rule string =
+    "module A exposing (..)\n\n"
+        ++ string
+        |> Review.Test.runWithProjectData project rule
+
+
+baseRule : Rule.Schema Rule.ForLookingAtASingleFile { hasAtLeastOneVisitor : () } Context
+baseRule =
+    Rule.newSchema "TestRule"
+        |> Rule.withInitialContext initialContext
+        |> Scope.addVisitors
+            { setter = \scope context -> { context | scope = scope }
+            , getter = .scope
+            }
+
+
+initialContext : Context
+initialContext =
+    { scope = Scope.initialContext
+    , text = ""
+    }
+
+
+all : Test
+all =
+    Test.describe "Scope"
+        [ Test.describe "Scope.realFunctionOrType"
+            [ test "should indicate that module from which a function or value comes from" <|
+                \() ->
+                    let
+                        rule : Rule
+                        rule =
+                            baseRule
+                                |> Rule.withExpressionVisitor expressionVisitor
+                                |> Rule.withFinalEvaluation finalEvaluation
+                                |> Rule.fromSchema
+
+                        expressionVisitor : Node Expression -> Rule.Direction -> Context -> ( List Rule.Error, Context )
+                        expressionVisitor node direction context =
+                            case ( direction, Node.value node ) of
+                                ( Rule.OnEnter, Expression.FunctionOrValue moduleName name ) ->
+                                    let
+                                        nameInCode : String
+                                        nameInCode =
+                                            case moduleName of
+                                                [] ->
+                                                    "<nothing>." ++ name
+
+                                                _ ->
+                                                    String.join "." moduleName ++ "." ++ name
+
+                                        realName : String
+                                        realName =
+                                            case Scope.realFunctionOrType moduleName name context.scope of
+                                                ( [], name_ ) ->
+                                                    "<nothing>." ++ name_
+
+                                                ( moduleName_, name_ ) ->
+                                                    String.join "." moduleName_ ++ "." ++ name_
+                                    in
+                                    ( [], { context | text = context.text ++ "\n" ++ nameInCode ++ " -> " ++ realName } )
+
+                                _ ->
+                                    ( [], context )
+
+                        finalEvaluation : Context -> List Rule.Error
+                        finalEvaluation context =
+                            [ Rule.error { message = context.text, details = [ "details" ] }
+                                { start = { row = 1, column = 1 }
+                                , end = { row = 1, column = 7 }
+                                }
+                            ]
+                    in
+                    testRule rule """
+import Bar as Baz exposing (baz)
+import Foo
+import Foo.Bar
+import Html exposing (..)
+import Http exposing (get)
+
+a = b
+    Foo.bar
+    Foo.Bar
+    Baz.foo
+    baz
+    button
+    Http.get
+    get
+"""
+                        |> Review.Test.expectErrors
+                            [ Review.Test.error
+                                { message = """
+<nothing>.b -> <nothing>.b
+Foo.bar -> Foo.bar
+Foo.Bar -> Foo.Bar
+Baz.foo -> Bar.foo
+<nothing>.baz -> Bar.baz
+<nothing>.button -> Html.button
+Http.get -> Http.get
+<nothing>.get -> Http.get"""
+                                , details = [ "details" ]
+                                , under = "module"
+                                }
+                            ]
+            ]
+        ]