Add support for associating a severity to a rule

lintingDir/src/LintApp.elm

@@ -1,9 +1,8 @@
 port module LintApp exposing (..)
 
 import Json.Decode
-import Dict exposing (Dict)
 import Lint exposing (lintSource)
-import Lint.Types exposing (LintError)
+import Lint.Types exposing (LintRule, LintError, Severity(..))
 import LintConfig exposing (config)
 
 
@@ -27,14 +26,24 @@ type Msg
     = Lint (List File)
 
 
-lint : String -> List String
-lint source =
-    case lintSource config source of
-        Err errors ->
-            errors
+enabledRules : List ( Severity, LintRule )
+enabledRules =
+    config
+        |> List.filter (Tuple.first >> (/=) Disabled)
 
-        Ok errors ->
-            errors
+
+lint : String -> List ( Severity, LintError )
+lint source =
+    lintSource enabledRules source
+        |> (\result ->
+                case result of
+                    Err errors ->
+                        [ ( Critical, { rule = "ParseError", message = String.join "\n" errors } )
+                        ]
+
+                    Ok result ->
+                        result
+           )
 
 
 update : Msg -> Model -> ( Model, Cmd Msg )
@@ -43,8 +52,10 @@ update msg model =
         Lint files ->
             let
                 lintResult =
-                    List.map (\file -> ( file, lint file.source )) files
-                        |> List.filter (Tuple.second >> List.isEmpty >> not)
+                    files
+                        |> List.map (\file -> ( file, lint file.source ))
+                        |> List.filter
+                            (Tuple.second >> List.isEmpty >> not)
                         |> List.map formatReport
                         |> String.join "\n\n"
             in
@@ -67,10 +78,31 @@ main =
         }
 
 
-formatReport : ( File, List String ) -> String
+formatSeverity : Severity -> String
+formatSeverity severity =
+    case severity of
+        Disabled ->
+            "Disabled"
+
+        Warning ->
+            "Warning"
+
+        Critical ->
+            "Critical"
+
+
+formatReport : ( File, List ( Severity, LintError ) ) -> String
 formatReport ( { filename }, errors ) =
-    (toString (List.length errors))
-        ++ " errors found in '"
-        ++ filename
-        ++ "':\n\n\t"
-        ++ (String.join "\n\t" errors)
+    let
+        formattedErrors =
+            List.map
+                (\( severity, { rule, message } ) ->
+                    "(" ++ (formatSeverity severity) ++ ") " ++ rule ++ ": " ++ message
+                )
+                errors
+    in
+        (toString (List.length errors))
+            ++ " errors found in '"
+            ++ filename
+            ++ "':\n\n\t"
+            ++ (String.join "\n\t" formattedErrors)

lintingDir/src/LintConfig.elm

@@ -1,6 +1,6 @@
 module LintConfig exposing (config)
 
-import Lint.Types exposing (LintRule)
+import Lint.Types exposing (LintRule, Severity(..))
 import Lint.Rules.DefaultPatternPosition
 import Lint.Rules.NoConstantCondition
 import Lint.Rules.NoDebug
@@ -17,20 +17,20 @@ import Lint.Rules.SimplifyPiping
 import Lint.Rules.SimplifyPropertyAccess
 
 
-config : List LintRule
+config : List ( Severity, LintRule )
 config =
-    [ Lint.Rules.DefaultPatternPosition.rule { position = Lint.Rules.DefaultPatternPosition.Last }
-    , Lint.Rules.NoConstantCondition.rule
-    , Lint.Rules.NoDebug.rule
-    , Lint.Rules.NoDuplicateImports.rule
-    , Lint.Rules.NoExposingEverything.rule
-    , Lint.Rules.NoImportingEverything.rule
-    , Lint.Rules.NoNestedLet.rule
-    , Lint.Rules.NoUnannotatedFunction.rule
-    , Lint.Rules.NoUnusedVariables.rule
-    , Lint.Rules.NoUselessIf.rule
-    , Lint.Rules.NoUselessPatternMatching.rule
-    , Lint.Rules.NoWarningComments.rule
-    , Lint.Rules.SimplifyPiping.rule
-    , Lint.Rules.SimplifyPropertyAccess.rule
+    [ ( Critical, Lint.Rules.DefaultPatternPosition.rule { position = Lint.Rules.DefaultPatternPosition.Last } )
+    , ( Critical, Lint.Rules.NoConstantCondition.rule )
+    , ( Critical, Lint.Rules.NoDebug.rule )
+    , ( Critical, Lint.Rules.NoDuplicateImports.rule )
+    , ( Critical, Lint.Rules.NoExposingEverything.rule )
+    , ( Critical, Lint.Rules.NoImportingEverything.rule )
+    , ( Critical, Lint.Rules.NoNestedLet.rule )
+    , ( Critical, Lint.Rules.NoUnannotatedFunction.rule )
+    , ( Critical, Lint.Rules.NoUnusedVariables.rule )
+    , ( Critical, Lint.Rules.NoUselessIf.rule )
+    , ( Critical, Lint.Rules.NoUselessPatternMatching.rule )
+    , ( Warning, Lint.Rules.NoWarningComments.rule )
+    , ( Critical, Lint.Rules.SimplifyPiping.rule )
+    , ( Critical, Lint.Rules.SimplifyPropertyAccess.rule )
     ]

src/Lint.elm

@@ -34,7 +34,7 @@ import Ast
 import Ast.Expression exposing (Expression)
 import Ast.Statement
 import Combine
-import Lint.Types exposing (LintRule, LintResult, LintError, LintImplementation, LintRuleImplementation, Direction, Visitor)
+import Lint.Types exposing (LintRule, LintResult, LintError, LintImplementation, LintRuleImplementation, Direction, Visitor, Severity, Severity(..))
 import Lint.Visitor exposing (transformStatementsIntoVisitors, expressionToVisitors)
 import Regex
 
@@ -44,22 +44,27 @@ import Regex
     errors =
         lintSource rules source
 -}
-lintSource : List LintRule -> String -> Result (List String) (List String)
+lintSource : List ( Severity, LintRule ) -> String -> Result (List String) (List ( Severity, LintError ))
 lintSource rules source =
-    let
-        sourceParsingResult =
-            parseSource source
-    in
-        case sourceParsingResult of
-            Err err ->
-                Err err
-
-            Ok parsedSource ->
+    source
+        |> parseSource
+        |> Result.map
+            (\_ ->
                 rules
                     |> List.concatMap
-                        (\rule -> rule source |> Result.withDefault [])
-                    |> List.map (\err -> err.rule ++ ": " ++ err.message)
-                    |> Ok
+                        (lintSourceWithRule source)
+            )
+
+
+
+-- type alias Reporter a =  -> a
+
+
+lintSourceWithRule : String -> ( Severity, LintRule ) -> List ( Severity, LintError )
+lintSourceWithRule source ( severity, rule ) =
+    rule source
+        |> Result.map (List.map ((,) severity))
+        |> Result.withDefault []
 
 
 parseSource : String -> Result (List String) (Combine.ParseOk () (List Ast.Statement.Statement))
@@ -67,14 +72,7 @@ parseSource source =
     source
         |> removeComments
         |> Ast.parse
-        |> (\sourceParsingResult ->
-                case sourceParsingResult of
-                    Err ( _, _, errors ) ->
-                        Err errors
-
-                    Ok parsedSource ->
-                        Ok parsedSource
-           )
+        |> Result.mapError (\( _, _, errors ) -> errors)
 
 
 removeComments : String -> String

src/Lint/Types.elm

@@ -1,12 +1,15 @@
-module Lint.Types exposing (LintError, LintImplementation, Direction(..), LintRule, LintRuleImplementation, LintResult, Visitor)
+module Lint.Types exposing (LintError, LintImplementation, Direction(..), LintRule, LintRuleImplementation, LintResult, Visitor, Severity, Severity(..))
 
 {-| This module contains types that are used for writing rules.
 
 # Elementary types
 @docs LintError, Direction
 
+# Configuration
+@docs LintRule, Severity
+
 # Writing rules
-@docs LintRuleImplementation, LintImplementation, LintRule
+@docs LintRuleImplementation, LintImplementation
 
 # Internal types
 @docs Visitor, LintResult
@@ -127,3 +130,15 @@ Note: this is internal API, and will be removed in a future version.
 -}
 type alias Visitor context =
     LintRuleImplementation context -> context -> ( List LintError, context )
+
+
+{-| Severity associated to a rule.
+
+- Critical: Transgressions reported by the rule will make the linting process fail.
+- Warning: Transgressions reported by the rule will not make the linting process fail.
+- Disabled: Rule will not be enforced.
+-}
+type Severity
+    = Disabled
+    | Warning
+    | Critical