Fixed bug when matching against literals

would check to make sure the pattern was camelcase as it thought it was
the binding of a new value, but it could be a literal, so the fix is to
check whether or not the value is implemented at the location of the
pattern

Author: Matt

src/FSharpLint.Framework/AstInfo.fs

@@ -103,6 +103,7 @@ module AstInfo =
 
         isPublic true false path
 
+    /// Is an identifier being used to identify declaration of a value?
     let isValue (identifier:LongIdent) (checkFile:CheckFileResults) =
         if System.Char.IsUpper(identifier.Head.idText.[0]) && identifier.Length = 1 then
             let identifier = identifier.Head
@@ -115,7 +116,15 @@ module AstInfo =
             match symbol with
                 | Some(symbol) ->
                     match symbol.Symbol with
-                        | :? FSharpMemberFunctionOrValue -> true
+                        | :? FSharpMemberFunctionOrValue as symbol -> 
+                            match symbol.ImplementationLocation with
+                                | Some(implLocation) -> 
+                                    /// If it's implemented elsewhere then it's not what we're looking for,
+                                    /// it's probably a literal being matched against.
+                                    let isImplementedHere = implLocation.StartRange = identifier.idRange.StartRange
+
+                                    isImplementedHere
+                                | None -> true
                         | _ -> false
                 | None -> false
         else 

tests/FSharpLint.Rules.Tests/TestNameConventionRules.fs

@@ -366,6 +366,20 @@ namespace matt.dog.cat"""
 
         Assert.IsTrue(this.ErrorExistsAt(2, 10))
 
+    [<Test>]
+    member this.LiteralPatternMatchExpectNoErrors() = 
+        this.Parse """
+module program
+  [<Literal>]
+  let Dog = true
+
+  let main = 
+    match true with
+    | Dog -> ()
+    | _ -> ()"""
+
+        Assert.IsFalse(this.ErrorExistsAt(8, 6))
+
     [<Test>]
     member this.VariablePatternMatchIsPascalCase() = 
         this.Parse """
@@ -375,7 +389,7 @@ module program
     | Dog -> ()"""
 
         Assert.IsTrue(this.ErrorExistsAt(5, 6))
-
+        
     [<Test>]
     member this.VariablePatternMatchIsCamelCase() = 
         this.Parse """