Add ScopeExample

tests/ScopeExample.elm

@@ -0,0 +1,47 @@
+module ScopeExample exposing (rule)
+
+import Elm.Syntax.Expression as Expression exposing (Expression)
+import Elm.Syntax.Node as Node exposing (Node)
+import Review.Rule as Rule exposing (Direction, Error, Rule)
+import Scope
+
+
+rule : Rule
+rule =
+    Rule.newModuleRuleSchema "NoHtmlButton" initialContext
+        |> Scope.addModuleVisitors
+        |> Rule.withExpressionEnterVisitor expressionVisitor
+        |> Rule.fromModuleRuleSchema
+        |> Rule.ignoreErrorsForFiles [ "src/Button.elm" ]
+
+
+type alias Context =
+    { scope : Scope.ModuleContext
+    }
+
+
+initialContext : Context
+initialContext =
+    { scope = Scope.initialModuleContext
+    }
+
+
+expressionVisitor : Node Expression -> Context -> ( List (Error {}), Context )
+expressionVisitor node context =
+    case Node.value node of
+        Expression.FunctionOrValue moduleName "button" ->
+            if Scope.moduleNameForValue context.scope "button" moduleName == [ "Html" ] then
+                ( [ Rule.error
+                        { message = "Do not use `Html.button` directly"
+                        , details = [ "At fruits.com, we've built a nice `Button` module that suits our needs better. Using this module instead of `Html.button` ensures we have a consistent button experience across the website." ]
+                        }
+                        (Node.range node)
+                  ]
+                , context
+                )
+
+            else
+                ( [], context )
+
+        _ ->
+            ( [], context )