Core,Tests: fix FSharpLint warning

Fixing the warning for FavourStaticEmptyFields rule.

Author: Mersho

src/FSharpLint.Core/Application/Configuration.fs

@@ -39,7 +39,7 @@ module FSharpJsonConverter =
                 else innerType
             let value = serializer.Deserialize(reader, innerType)
             let cases = FSharpType.GetUnionCases(t)
-            if isNull value then FSharpValue.MakeUnion(cases.[0], [||])
+            if isNull value then FSharpValue.MakeUnion(cases.[0], Array.empty)
             else FSharpValue.MakeUnion(cases.[1], [|value|])
 
     let private converters =
@@ -104,7 +104,7 @@ module IgnoreFiles =
                 else doesGlobSeqMatchPathSeq remaining currentlyMatchingGlobs
             | [] -> false
 
-        doesGlobSeqMatchPathSeq path []
+        doesGlobSeqMatchPathSeq path List.Empty
 
     let shouldFileBeIgnored (ignorePaths:Ignore list) (filePath:string) =
         let segments = filePath.Split Path.DirectorySeparatorChar |> Array.toList
@@ -374,7 +374,7 @@ with
             this.noTabCharacters |> Option.bind (constructRuleIfEnabled NoTabCharacters.rule) |> Option.toArray
         |] |> Array.concat
 
-let private getOrEmptyList hints = hints |> Option.defaultValue [||]
+let private getOrEmptyList hints = hints |> Option.defaultValue Array.empty
 
 type HintConfig = {
     add:string [] option

src/FSharpLint.Core/Application/Lint.fs

@@ -497,7 +497,7 @@ module Lint =
                         | LintResult.Success warnings ->
                             (List.append warnings successes, failures)
                         | LintResult.Failure err ->
-                            (successes, err :: failures)) ([], [])
+                            (successes, err :: failures)) (List.Empty, List.Empty)
 
                 match failures with
                 | [] ->

src/FSharpLint.Core/Framework/AbstractSyntaxArray.fs

@@ -300,5 +300,5 @@ module AbstractSyntaxArray =
             else
                 breadcrumbs
 
-        if i = 0 then []
-        else getBreadcrumbs [] (syntaxArray.[i].ParentIndex) |> List.rev
+        if i = 0 then List.Empty
+        else getBreadcrumbs List.Empty (syntaxArray.[i].ParentIndex) |> List.rev

src/FSharpLint.Core/Framework/Ast.fs

@@ -68,7 +68,7 @@ module Ast =
 
         match functionApplication with
         | AstNode.Expression(SynExpr.App(_, _, _, _, range) as functionApplication) ->
-            Some(flatten [] functionApplication, range)
+            Some(flatten List.Empty functionApplication, range)
         | _ -> None
 
     [<NoEquality; NoComparison>]
@@ -100,7 +100,7 @@ module Ast =
 
         match lambda with
         | AstNode.Expression(SynExpr.Lambda(_, _, _, _, _, range, _) as lambda) ->
-            getLambdaParametersAndExpression [] lambda
+            getLambdaParametersAndExpression List.Empty lambda
             |> Option.map (fun x -> (x, range))
         | _ -> None
 
@@ -174,7 +174,7 @@ module Ast =
             match pat with
             | SynSimplePats.SimplePats(patterns, _range) -> patterns @ acc
             | SynSimplePats.Typed(patterns, _type, _range) -> loop patterns acc
-        loop simplePats []
+        loop simplePats List.Empty
 
     let inline private memberDefinitionChildren node add =
         match node with

src/FSharpLint.Core/Framework/HintParser.fs

@@ -1,5 +1,6 @@
 namespace FSharpLint.Framework
 
+open System
 open FParsec
 open FSharp.Compiler.Tokenization
 
@@ -146,7 +147,7 @@ module HintParser =
 
             override this.GetHashCode() = hash (this.AnyMatch, hash this.Lookup)
 
-            static member Empty = { Lookup = Dictionary<_, _>(); AnyMatch = [] }
+            static member Empty = { Lookup = Dictionary<_, _>(); AnyMatch = List.Empty }
 
         let private getConstKey = function
             | Constant.Unit -> SyntaxHintNode.Unit
@@ -235,7 +236,7 @@ module HintParser =
             | HintExpr(Expression.Constant(_))
             | HintExpr(Expression.Null)
             | HintExpr(Expression.Wildcard)
-            | HintExpr(Expression.Variable(_)) -> []
+            | HintExpr(Expression.Variable(_)) -> List.Empty
             | HintPat(Pattern.Cons(lhs, rhs))
             | HintPat(Pattern.Or(lhs, rhs)) -> [HintPat lhs; HintPat rhs]
             | HintPat(Pattern.Array(patterns))
@@ -246,7 +247,7 @@ module HintParser =
             | HintPat(Pattern.Identifier(_))
             | HintPat(Pattern.Constant(_))
             | HintPat(Pattern.Wildcard)
-            | HintPat(Pattern.Null) -> []
+            | HintPat(Pattern.Null) -> List.Empty
 
         let private getConstantHashCode = function
             | Constant.Bool(x) -> hash x
@@ -320,7 +321,7 @@ module HintParser =
                     transposeHead next rest
                 | [] -> builtList
 
-            transposeHead [] hintLists
+            transposeHead List.Empty hintLists
 
         let isAnyMatch = function
             | ((SyntaxHintNode.Wildcard | SyntaxHintNode.Variable), _, _, _) -> true
@@ -387,7 +388,7 @@ module HintParser =
             getEdges transposed
 
     let charListToString charList =
-        Seq.fold (fun x y -> x + y.ToString()) "" charList
+        Seq.fold (fun x y -> x + y.ToString()) String.Empty charList
 
     let pischar chars : Parser<char, 'T> =
         satisfy (fun x -> List.exists ((=) x) chars)
@@ -424,7 +425,7 @@ module HintParser =
             pidentstartchar .>>. many pidentchar
             |>> fun (start, rest) -> start::rest
             >>= fun ident ->
-                let identStr = System.String.Join("", ident)
+                let identStr = System.String.Join(String.Empty, ident)
 
                 let isKeyword = List.exists ((=) identStr) FSharpKeywords.KeywordNames
 
@@ -902,9 +903,9 @@ module HintParser =
         let addInfixOperator prefix precedence associativity =
             let remainingOpChars =
                 if prefix = "=" then
-                    notFollowedBy (pstring "==>") |>> fun _ -> ""
+                    notFollowedBy (pstring "==>") |>> fun _ -> String.Empty
                 else if prefix = "|" then
-                    notFollowedBy (pstring "]") |>> fun _ -> ""
+                    notFollowedBy (pstring "]") |>> fun _ -> String.Empty
                 else
                     manySatisfy (isAnyOf Operators.opchars)
 
@@ -922,7 +923,7 @@ module HintParser =
                 else if prefix = "~" then
                     manySatisfy ((=) '~')
                 else
-                    preturn ""
+                    preturn String.Empty
 
             let checkPrefix remOpChars expr =
                 if prefix = "&" then Expression.AddressOf(true, expr)
@@ -1026,7 +1027,7 @@ module HintParser =
         let addInfixOperator operator precedence associativity =
             let remainingOpChars =
                 if operator = "|" then
-                    notFollowedBy (pstring "]") |>> fun _ -> ""
+                    notFollowedBy (pstring "]") |>> fun _ -> String.Empty
                 else
                     manySatisfy (isAnyOf Operators.opchars)
 

src/FSharpLint.Core/Framework/Utilities.fs

@@ -42,7 +42,7 @@ module ExpressionUtilities =
             checkFile.GetSymbolUseAtLocation(
                 range.StartLine,
                 range.EndColumn,
-                "",
+                String.Empty,
                 identNames)
         | _ -> None
 
@@ -94,7 +94,7 @@ module ExpressionUtilities =
         | _ -> None
 
     let getLeadingSpaces (range:Range) (text:string) =
-        let range = Range.mkRange "" (Position.mkPos range.StartLine 0) range.End
+        let range = Range.mkRange String.Empty (Position.mkPos range.StartLine 0) range.End
         tryFindTextOfRange range text
         |> Option.map (fun text ->
             text.ToCharArray()
@@ -119,7 +119,7 @@ module ExpressionUtilities =
 
     /// Counts the number of comment lines preceding the given range of text.
     let countPrecedingCommentLines (text:string) (startPos:pos) (endPos:pos) =
-        let range = Range.mkRange "" startPos endPos
+        let range = Range.mkRange String.Empty startPos endPos
 
         let map (precedingText: string) =
             let lines =

src/FSharpLint.Core/Rules/Conventions/AvoidSinglePipeOperator.fs

@@ -21,7 +21,7 @@ let runner (args: AstNodeRuleParams) =
         let checkParentPiped (expr: AstNode) =
             match expr with
             | AstNode.Expression(SynExpr.App(_exprAtomicFlag, _isInfix, funcExpr, _argExpr, _range)) ->
-                checkExpr funcExpr [] |> Seq.isEmpty
+                checkExpr funcExpr List.Empty |> Seq.isEmpty
             | _ -> false
 
         match expr with

src/FSharpLint.Core/Rules/Conventions/Binding/FavourIgnoreOverLetWild.fs

@@ -14,10 +14,13 @@ let private checkForBindingToAWildcard pattern range =
         | _ -> false
 
     if findWildAndIgnoreParens pattern then
-        { Range = range
-          Message = Resources.GetString("RulesFavourIgnoreOverLetWildError")
-          SuggestedFix = None
-          TypeChecks = [] } |> Array.singleton
+        {
+            Range = range
+            Message = Resources.GetString("RulesFavourIgnoreOverLetWildError")
+            SuggestedFix = None
+            TypeChecks = List.Empty
+        }
+        |> Array.singleton
     else
         Array.empty
 

src/FSharpLint.Core/Rules/Conventions/Binding/FavourTypedIgnore.fs

@@ -19,10 +19,12 @@ let private runner (args: AstNodeRuleParams) =
                            FromRange = range
                            ToText = identifier }))
 
-        { Range = range
-          Message = String.Format(Resources.GetString "RulesFavourTypedIgnore", identifier)
-          SuggestedFix = Some suggestedFix
-          TypeChecks = [] }
+        {
+            Range = range
+            Message = String.Format(Resources.GetString "RulesFavourTypedIgnore", identifier)
+            SuggestedFix = Some suggestedFix
+            TypeChecks = List.Empty
+        }
 
     let isTyped expression identifier range text =
         match expression with

src/FSharpLint.Core/Rules/Conventions/Binding/TupleOfWildcards.fs

@@ -24,7 +24,13 @@ let private checkTupleOfWildcards pattern identifier =
         let refactorFrom = constructorString (List.length patterns)
         let refactorTo = (constructorString 1)
         let error = System.String.Format(errorFormat, refactorFrom, refactorTo)
-        { Range = range; Message = error; SuggestedFix = None; TypeChecks = [] } |> Array.singleton
+        {
+            Range = range
+            Message = error
+            SuggestedFix = None
+            TypeChecks = List.Empty
+        }
+        |> Array.singleton
     | _ -> Array.empty
 
 let private isTupleMemberArgs breadcrumbs tupleRange =

src/FSharpLint.Core/Rules/Conventions/Binding/UselessBinding.fs

@@ -25,7 +25,7 @@ let private checkForUselessBinding (checkInfo:FSharpCheckFileResults option) pat
         let checkNotMutable (ident:Ident) = fun () ->
             let symbol =
                 checkInfo.GetSymbolUseAtLocation(
-                    ident.idRange.StartLine, ident.idRange.EndColumn, "", [ident.idText])
+                    ident.idRange.StartLine, ident.idRange.EndColumn, String.Empty, [ident.idText])
 
             match symbol with
             | Some(symbol) -> isNotMutable symbol

src/FSharpLint.Core/Rules/Conventions/Binding/WildcardNamedWithAsPattern.fs

@@ -10,10 +10,13 @@ open FSharpLint.Framework.Rules
 let private checkForWildcardNamedWithAsPattern pattern =
     match pattern with
     | SynPat.Wild(range) ->
-        { Range = range
-          Message = Resources.GetString("RulesWildcardNamedWithAsPattern")
-          SuggestedFix = None
-          TypeChecks = [] } |> Array.singleton
+        {
+            Range = range
+            Message = Resources.GetString("RulesWildcardNamedWithAsPattern")
+            SuggestedFix = None
+            TypeChecks = List.Empty
+        }
+        |> Array.singleton
     | _ -> Array.empty
 
 let private runner (args:AstNodeRuleParams) =

src/FSharpLint.Core/Rules/Conventions/CyclomaticComplexity.fs

@@ -38,7 +38,7 @@ type private BindingScopeComparer() =
 
 ///  A two-tiered stack-like structure for containing BindingScopes.
 type private BindingStack(maxComplexity: int) =
-    let mutable tier1 = []
+    let mutable tier1 = List.Empty
     let mutable tier2 = SortedSet<BindingScope>(BindingScopeComparer())
 
     member this.Push (args:AstNodeRuleParams) (bs: BindingScope) =
@@ -76,7 +76,7 @@ type private BindingStack(maxComplexity: int) =
 
     /// Clears the stack.
     member this.Clear() =
-        tier1 <- []
+        tier1 <- List.Empty
         tier2.Clear()
 
 /// A stack to track the current cyclomatic complexity of a binding scope.
@@ -194,7 +194,7 @@ let runner (config:Config) (args:AstNodeRuleParams) : WarningDetails[] =
                                  pos.Column, pos.Line)
                             |> Seq.map (fun scope -> // transform into WarningDetails
                                 let errMsg = String.Format(Resources.GetString("RulesCyclomaticComplexityError"), scope.Complexity, config.MaxComplexity)
-                                { Range = scope.Binding.RangeOfBindingWithRhs; Message = errMsg; SuggestedFix = None; TypeChecks = [] })
+                                { Range = scope.Binding.RangeOfBindingWithRhs; Message = errMsg; SuggestedFix = None; TypeChecks = List.Empty })
                             |> Seq.toList
             let ret = match warningDetails with
                       | Some x -> x::fromStack

src/FSharpLint.Core/Rules/Conventions/FavourNonMutablePropertyInitialization.fs

@@ -53,12 +53,12 @@ let rec private processLetBinding (instanceNames: Set<string>) (body: SynExpr) :
         Array.append
             (processLetBinding instanceNames expr1)
             (processLetBinding instanceNames expr2)
-    | _ -> [||]
+    | _ -> Array.empty
 
 and processExpression (expression: SynExpr) : array<WarningDetails> =
     match expression with
     | SynExpr.LetOrUse(_, _, bindings, body, _, _) ->
-        let instanceNames = extraFromBindings bindings [] |> Set.ofList
+        let instanceNames = extraFromBindings bindings List.Empty |> Set.ofList
         processLetBinding instanceNames body
     | SynExpr.Sequential(_, _, expr1, expr2, _) ->
         Array.append
@@ -69,7 +69,7 @@ and processExpression (expression: SynExpr) : array<WarningDetails> =
 let runner args =
     match args.AstNode with
     | Binding(SynBinding(_, _, _, _, _, _, _, _, _, SynExpr.LetOrUse(_, _, bindings, body, _, _), _, _, _)) ->
-        let instanceNames = extraFromBindings bindings [] |> Set.ofList
+        let instanceNames = extraFromBindings bindings List.Empty |> Set.ofList
         processLetBinding instanceNames body
     | Match(SynMatchClause(_, _, expr, _, _, _)) ->
         processExpression expr

src/FSharpLint.Core/Rules/Conventions/FunctionReimplementation/CanBeReplacedWithComposition.fs

@@ -41,10 +41,13 @@ let private validateLambdaCannotBeReplacedWithComposition _ lambda range =
         | _ -> false
 
     if canBeReplacedWithFunctionComposition lambda.Body then
-        { Range = range
-          Message = Resources.GetString("RulesCanBeReplacedWithComposition")
-          SuggestedFix = None
-          TypeChecks = [] } |> Array.singleton
+        {
+            Range = range
+            Message = Resources.GetString("RulesCanBeReplacedWithComposition")
+            SuggestedFix = None
+            TypeChecks = List.Empty
+        }
+        |> Array.singleton
     else
         Array.empty
 

src/FSharpLint.Core/Rules/Conventions/FunctionReimplementation/ReimplementsFunction.fs

@@ -35,10 +35,12 @@ let private validateLambdaIsNotPointless (text:string) lambda range =
             ExpressionUtilities.tryFindTextOfRange range text
             |> Option.map (fun fromText -> { FromText = fromText; FromRange = range; ToText = identifier }))
 
-        { Range = range
-          Message = String.Format(Resources.GetString("RulesReimplementsFunction"), identifier)
-          SuggestedFix = Some suggestedFix
-          TypeChecks = [] }
+        {
+            Range = range
+            Message = String.Format(Resources.GetString("RulesReimplementsFunction"), identifier)
+            SuggestedFix = Some suggestedFix
+            TypeChecks = List.Empty
+        }
 
     let argumentsAsIdentifiers =
         lambda.Arguments