Activate suggestions in unit tests and move some tests

tests/fsharp/Compiler/CompilerAssert.fs

@@ -28,7 +28,7 @@ type ILVerifier (dllFilePath: string) =
 [<RequireQualifiedAccess>]
 module CompilerAssert =
 
-    let checker = FSharpChecker.Create()
+    let checker = FSharpChecker.Create(suggestNamesForErrors=true)
 
     let private config = TestFramework.initializeSuite ()
 

tests/fsharp/Compiler/ErrorMessages/ClassesTests.fs

@@ -88,7 +88,7 @@ let x =
   }
             """
             [|
-                FSharpErrorSeverity.Error, 767, (8, 14, 8, 34), "The member 'Function' does not correspond to any abstract or virtual method available to override or implement."
+                FSharpErrorSeverity.Error, 767, (8, 14, 8, 34), "The member 'Function' does not correspond to any abstract or virtual method available to override or implement. Maybe you want one of the following:\r\n   MyFunction"
                 FSharpErrorSeverity.Error, 17, (8, 19, 8, 27), "The member 'Function : 'a * 'b -> unit' does not have the correct type to override any given virtual method"
                 FSharpErrorSeverity.Error, 366, (7, 3, 9, 4), "No implementation was given for those members: \r\n\t'abstract member IInterface.MyFunction : int32 * int32 -> unit'\r\n\t'abstract member IInterface.SomeOtherFunction : int32 * int32 -> unit'\r\nNote that all interface members must be implemented and listed under an appropriate 'interface' declaration, e.g. 'interface ... with member ...'."
                 FSharpErrorSeverity.Error, 783, (7, 9, 7, 19), "At least one override did not correctly implement its corresponding abstract member"

tests/fsharp/Compiler/ErrorMessages/ConstructorTests.fs

@@ -47,7 +47,7 @@ let p =
            Age = 18)
             """
             [|
-                FSharpErrorSeverity.Error, 39, (7, 12, 7, 16), "The value or constructor 'Name' is not defined."
+                FSharpErrorSeverity.Error, 39, (7, 12, 7, 16), "The value or constructor 'Name' is not defined. Maybe you want one of the following:\r\n   nan"
                 FSharpErrorSeverity.Warning, 20, (7, 12, 7, 25), "The result of this equality expression has type 'bool' and is implicitly discarded. Consider using 'let' to bind the result to a name, e.g. 'let result = expression'."
                 FSharpErrorSeverity.Error, 39, (8, 12, 8, 15), "The value or constructor 'Age' is not defined."
                 FSharpErrorSeverity.Error, 501, (7, 5, 8, 21), "The object constructor 'Person' takes 0 argument(s) but is here given 1. The required signature is 'new : unit -> Person'. If some of the arguments are meant to assign values to properties, consider separating those arguments with a comma (',')."

tests/fsharp/Compiler/ErrorMessages/DontSuggestTests.fs

@@ -17,7 +17,7 @@ let _ = Path.GetFullPath "images"
             FSharpErrorSeverity.Error
             39
             (2, 9, 2, 13)
-            "The value, namespace, type or module 'Path' is not defined."
+            "The value, namespace, type or module 'Path' is not defined. Maybe you want one of the following:\r\n   Math"
 
     [<Test>]
     let ``Dont Suggest When Things Are Open``() =

tests/fsharp/Compiler/ErrorMessages/NameResolutionTests.fs

@@ -6,8 +6,8 @@ open NUnit.Framework
 open FSharp.Compiler.SourceCodeServices
 
 [<TestFixture>]
-module NameResolutionTests = 
-    
+module NameResolutionTests =
+
     [<Test>]
     let FieldNotInRecord () =
         CompilerAssert.TypeCheckSingleError
@@ -24,7 +24,7 @@ let r:F = { Size=3; Height=4; Wall=1 }
             FSharpErrorSeverity.Error
             1129
             (9, 31, 9, 35)
-            "The record type 'F' does not contain a label 'Wall'."
+            "The record type 'F' does not contain a label 'Wall'. Maybe you want one of the following:\r\n   Wallis"
 
     [<Test>]
     let RecordFieldProposal () =
@@ -36,10 +36,10 @@ type C = { Wheels:int }
 type D = { Size:int; Height:int; Walls:int }
 type E = { Unknown:string }
 type F = { Wallis:int; Size:int; Height:int; }
-            
+
 let r = { Size=3; Height=4; Wall=1 }
             """
             FSharpErrorSeverity.Error
             39
             (9, 29, 9, 33)
-            "The record label 'Wall' is not defined."
+            "The record label 'Wall' is not defined. Maybe you want one of the following:\r\n   Walls\r\n   Wallis"

tests/fsharp/Compiler/ErrorMessages/SuggestionsTests.fs

@@ -0,0 +1,320 @@
+// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
+
+namespace FSharp.Compiler.UnitTests
+
+open NUnit.Framework
+open FSharp.Compiler.SourceCodeServices
+
+[<TestFixture>]
+module Suggestions =
+
+    [<Test>]
+    let ``Field Suggestion`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+type Person = { Name : string; }
+
+let x = { Person.Names = "Isaac" }
+            """
+            FSharpErrorSeverity.Error
+            39
+            (4, 18, 4, 23)
+            "The field, constructor or member 'Names' is not defined. Maybe you want one of the following:\r\n   Name"
+
+
+    [<Test>]
+    let ``Suggest Array Module Functions`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+let f =
+    Array.blt
+            """
+            FSharpErrorSeverity.Error
+            39
+            (3, 11, 3, 14)
+            "The value, constructor, namespace or type 'blt' is not defined. Maybe you want one of the following:\r\n   blit"
+
+
+    [<Test>]
+    let ``Suggest Async Module`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+let f =
+    Asnc.Sleep 1000
+            """
+            FSharpErrorSeverity.Error
+            39
+            (3, 5, 3, 9)
+            "The value, namespace, type or module 'Asnc' is not defined. Maybe you want one of the following:\r\n   Async\r\n   async\r\n   asin\r\n   snd"
+
+
+    [<Test>]
+    let ``Suggest Attribute`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+[<AbstractClas>]
+type MyClass<'Bar>() =
+   abstract M<'T> : 'T -> 'T
+   abstract M2<'T> : 'T -> 'Bar
+            """
+            FSharpErrorSeverity.Error
+            39
+            (2, 3, 2, 15)
+            "The type 'AbstractClas' is not defined. Maybe you want one of the following:\r\n   AbstractClass\r\n   AbstractClassAttribute"
+
+
+    [<Test>]
+    let ``Suggest Double Backtick Identifiers`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+module N =
+    let ``longer name`` = "hallo"
+
+let x = N.``longe name``
+            """
+            FSharpErrorSeverity.Error
+            39
+            (5, 11, 5, 25)
+            "The value, constructor, namespace or type 'longe name' is not defined. Maybe you want one of the following:\r\n   longer name"
+
+
+    [<Test>]
+    let ``Suggest Double Backtick Unions`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+module N =
+    type MyUnion =
+    | ``My Case1``
+    | Case2
+
+open N
+
+let x = N.MyUnion.``My Case2``
+            """
+            FSharpErrorSeverity.Error
+            39
+            (9, 19, 9,31)
+            "The field, constructor or member 'My Case2' is not defined. Maybe you want one of the following:\r\n   My Case1\r\n   Case2"
+
+
+    [<Test>]
+    let ``Suggest Fields In Constructor`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+type MyClass() =
+    member val MyProperty = "" with get, set
+    member val MyProperty2 = "" with get, set
+    member val ABigProperty = "" with get, set
+
+let c = MyClass(Property = "")
+            """
+            FSharpErrorSeverity.Error
+            495
+            (7, 17, 7, 25)
+            "The object constructor 'MyClass' has no argument or settable return property 'Property'. The required signature is new : unit -> MyClass. Maybe you want one of the following:\r\n   MyProperty\r\n   MyProperty2\r\n   ABigProperty"
+
+
+    [<Test>]
+    let ``Suggest Generic Type`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+type T = System.Collections.Generic.Dictionary<int11,int>
+            """
+            FSharpErrorSeverity.Error
+            39
+            (2, 48, 2, 53)
+            "The type 'int11' is not defined. Maybe you want one of the following:\r\n   int16\r\n   int16`1\r\n   int8\r\n   uint16\r\n   int"
+
+
+    [<Test>]
+    let ``Suggest Methods`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+module Test2 =
+    type D() =
+
+       static let x = 1
+
+       member x.Method1() = 10
+
+    D.Method2()
+            """
+            FSharpErrorSeverity.Error
+            39
+            (9, 7, 9, 14)
+            "The field, constructor or member 'Method2' is not defined. Maybe you want one of the following:\r\n   Method1"
+
+
+    [<Test>]
+    let ``Suggest Modules`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+module Collections =
+
+    let f () = printfn "%s" "Hello"
+
+open Collectons
+            """
+            FSharpErrorSeverity.Error
+            39
+            (6, 6, 6, 16)
+            "The namespace or module 'Collectons' is not defined. Maybe you want one of the following:\r\n   Collections"
+
+
+    [<Test>]
+    let ``Suggest Namespaces`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+open System.Collectons
+            """
+            FSharpErrorSeverity.Error
+            39
+            (2, 13, 2, 23)
+            "The namespace 'Collectons' is not defined."
+
+
+    [<Test>]
+    let ``Suggest Record Labels`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+type MyRecord = { Hello: int; World: bool}
+
+let r = { Hello = 2 ; World = true}
+
+let x = r.ello
+            """
+            FSharpErrorSeverity.Error
+            39
+            (6, 11, 6, 15)
+            "The field, constructor or member 'ello' is not defined. Maybe you want one of the following:\r\n   Hello"
+
+
+    [<Test>]
+    let ``Suggest Record Type for RequireQualifiedAccess Records`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+[<RequireQualifiedAccess>]
+type MyRecord = {
+    Field1: string
+    Field2: int
+}
+
+let r = { Field1 = "hallo"; Field2 = 1 }
+            """
+            FSharpErrorSeverity.Error
+            39
+            (8, 11, 8, 17)
+            "The record label 'Field1' is not defined. Maybe you want one of the following:\r\n   MyRecord.Field1"
+
+
+    [<Test>]
+    let ``Suggest To Use Indexer`` () =
+        CompilerAssert.TypeCheckWithErrors
+            """
+let d = [1,1] |> dict
+let y = d[1]
+
+let z = d[|1|]
+
+let f() = d
+let a = (f())[1]
+            """
+            [|
+                FSharpErrorSeverity.Error, 3217, (3, 9, 3, 10), "This value is not a function and cannot be applied. Did you intend to access the indexer via d.[index] instead?"
+                FSharpErrorSeverity.Error, 3, (5, 9, 5, 10), "This value is not a function and cannot be applied."
+                FSharpErrorSeverity.Error, 3217, (8, 10, 8, 13), "This expression is not a function and cannot be applied. Did you intend to access the indexer via expr.[index] instead?"
+            |]
+
+
+    [<Test>]
+    let ``Suggest Type Parameters`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+[<AbstractClass>]
+type MyClass<'Bar>() =
+   abstract M<'T> : 'T -> 'T
+   abstract M2<'T> : 'T -> 'Bar
+   abstract M3<'T> : 'T -> 'B
+            """
+            FSharpErrorSeverity.Error
+            39
+            (6, 28, 6, 30)
+            "The type parameter 'B is not defined."
+
+
+    [<Test>]
+    let ``Suggest Types in Module`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+let x : System.Collections.Generic.Lst = ResizeArray()
+            """
+            FSharpErrorSeverity.Error
+            39
+            (2, 36, 2, 39)
+            "The type 'Lst' is not defined in 'System.Collections.Generic'. Maybe you want one of the following:\r\n   List\r\n   IList\r\n   List`1"
+
+    [<Test>]
+    let ``Suggest Types in Namespace`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+let x = System.DateTie.MaxValue
+            """
+            FSharpErrorSeverity.Error
+            39
+            (2, 16, 2, 23)
+            "The value, constructor, namespace or type 'DateTie' is not defined. Maybe you want one of the following:\r\n   DateTime\r\n   DateTimeKind\r\n   DateTimeOffset\r\n   Data"
+
+
+    [<Test>]
+    let ``Suggest Union Cases`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+type MyUnion =
+| ASimpleCase
+| AnotherCase of int
+
+let u = MyUnion.AntherCase
+            """
+            FSharpErrorSeverity.Error
+            39
+            (6, 17, 6, 27)
+            "The field, constructor or member 'AntherCase' is not defined. Maybe you want one of the following:\r\n   AnotherCase"
+
+
+    [<Test>]
+    let ``Suggest Union Type for RequireQualifiedAccess Unions`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+[<RequireQualifiedAccess>]
+type MyUnion =
+| MyCase1
+| MyCase2 of string
+
+let x : MyUnion = MyCase1
+            """
+            FSharpErrorSeverity.Error
+            39
+            (7, 19, 7, 26)
+            "The value or constructor 'MyCase1' is not defined. Maybe you want one of the following:\r\n   MyUnion.MyCase1"
+
+
+    [<Test>]
+    let ``Suggest Unions in PatternMatch`` () =
+        CompilerAssert.TypeCheckSingleError
+            """
+[<RequireQualifiedAccess>]
+type MyUnion =
+| Case1
+| Case2
+
+let y = MyUnion.Case1
+
+let x =
+    match y with
+    | MyUnion.Cas1 -> 1
+    | _ -> 2
+            """
+            FSharpErrorSeverity.Error
+            39
+            (11, 15, 11, 19)
+            "The field, constructor or member 'Cas1' is not defined. Maybe you want one of the following:\r\n   Case1\r\n   Case2"