Moving WarnExpressionTests over to NUnit

tests/fsharp/Compiler/ErrorMessages/WarnExpressionTests.fs

@@ -0,0 +1,208 @@
+// 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 ``Warn Expression`` =
+
+    [<Test>]
+    let ``Warn If Expression Result Unused``() =
+        CompilerAssert.TypeCheckSingleError
+            """
+1 + 2
+printfn "%d" 3
+            """
+            FSharpErrorSeverity.Warning
+            20
+            (2, 1, 2, 6)
+            "The result of this expression has type 'int' and is implicitly ignored. Consider using 'ignore' to discard this value explicitly, e.g. 'expr |> ignore', or 'let' to bind the result to a name, e.g. 'let result = expr'."
+
+    [<Test>]
+    let ``Warn If Possible Assignment``() =
+        CompilerAssert.TypeCheckSingleError
+            """
+let x = 10
+let y = "hello"
+
+let changeX() =
+    x = 20
+    y = "test"
+            """
+            FSharpErrorSeverity.Warning
+            20
+            (6, 5, 6, 11)
+            "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'. If you intended to mutate a value, then mark the value 'mutable' and use the '<-' operator e.g. 'x <- expression'."
+
+    [<Test>]
+    let ``Warn If Possible Assignment To Mutable``() =
+        CompilerAssert.TypeCheckSingleError
+            """
+let mutable x = 10
+let y = "hello"
+
+let changeX() =
+    x = 20
+    y = "test"
+            """
+            FSharpErrorSeverity.Warning
+            20
+            (6, 5, 6, 11)
+            "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'. If you intended to mutate a value, then use the '<-' operator e.g. 'x <- expression'."
+
+    [<Test>]
+    let ``Warn If Possible dotnet Property Setter``() =
+        CompilerAssert.TypeCheckWithErrors
+            """
+open System
+
+let z = System.Timers.Timer()
+let y = "hello"
+
+let changeProperty() =
+    z.Enabled = true
+    y = "test"
+            """
+            [|
+                FSharpErrorSeverity.Warning, 760, (4, 9, 4, 30), "It is recommended that objects supporting the IDisposable interface are created using the syntax 'new Type(args)', rather than 'Type(args)' or 'Type' as a function value representing the constructor, to indicate that resources may be owned by the generated value"
+                FSharpErrorSeverity.Warning, 20, (8, 5, 8, 21), "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'. If you intended to set a value to a property, then use the '<-' operator e.g. 'z.Enabled <- expression'."
+            |]
+
+    [<Test>]
+    let ``Don't Warn If Property Without Setter``() =
+        CompilerAssert.TypeCheckSingleError
+            """
+type MyClass(property1 : int) =
+    member val Property2 = "" with get
+
+let x = MyClass(1)
+let y = "hello"
+
+let changeProperty() =
+    x.Property2 = "22"
+    y = "test"
+            """
+            FSharpErrorSeverity.Warning
+            20
+            (9, 5, 9, 23)
+            "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'."
+
+    [<Test>]
+    let ``Warn If Implicitly Discarded``() =
+        CompilerAssert.TypeCheckSingleError
+            """
+let x = 10
+let y = 20
+
+let changeX() =
+    y * x = 20
+    y = 30
+            """
+            FSharpErrorSeverity.Warning
+            20
+            (6, 5, 6, 15)
+            "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'."
+
+    [<Test>]
+    let ``Warn If Discarded In List``() =
+        CompilerAssert.TypeCheckSingleError
+            """
+let div _ _ = 1
+let subView _ _ = [1; 2]
+
+// elmish view
+let view model dispatch =
+   [
+       yield! subView model dispatch
+       div [] []
+   ]
+            """
+            FSharpErrorSeverity.Warning
+            3221
+            (9, 8, 9, 17)
+            "This expression returns a value of type 'int' but is implicitly discarded. Consider using 'let' to bind the result to a name, e.g. 'let result = expression'. If you intended to use the expression as a value in the sequence then use an explicit 'yield'."
+
+    [<Test>]
+    let ``Warn If Discarded In List 2``() =
+        CompilerAssert.TypeCheckSingleError
+            """
+// stupid things to make the sample compile
+let div _ _ = 1
+let subView _ _ = [1; 2]
+let y = 1
+
+// elmish view
+let view model dispatch =
+   [
+        div [] [
+           match y with
+           | 1 -> yield! subView model dispatch
+           | _ -> subView model dispatch
+        ]
+   ]
+            """
+            FSharpErrorSeverity.Warning
+            3222
+            (13, 19, 13, 41)
+            "This expression returns a value of type 'int list' but is implicitly discarded. Consider using 'let' to bind the result to a name, e.g. 'let result = expression'. If you intended to use the expression as a value in the sequence then use an explicit 'yield!'."
+
+    [<Test>]
+    let ``Warn If Discarded In List 3``() =
+        CompilerAssert.TypeCheckSingleError
+            """
+// stupid things to make the sample compile
+let div _ _ = 1
+let subView _ _ = true
+let y = 1
+
+// elmish view
+let view model dispatch =
+   [
+        div [] [
+           match y with
+           | 1 -> ()
+           | _ -> subView model dispatch
+        ]
+   ]
+            """
+            FSharpErrorSeverity.Warning
+            20
+            (13, 19, 13, 41)
+            "The result of this expression has type 'bool' and is implicitly ignored. Consider using 'ignore' to discard this value explicitly, e.g. 'expr |> ignore', or 'let' to bind the result to a name, e.g. 'let result = expr'."
+
+    [<Test>]
+    let ``Warn Only On Last Expression``() =
+        CompilerAssert.TypeCheckSingleError
+            """
+let mutable x = 0
+while x < 1 do
+    printfn "unneeded"
+    x <- x + 1
+    true
+            """
+            FSharpErrorSeverity.Warning
+            20
+            (6, 5, 6, 9)
+            "The result of this expression has type 'bool' and is implicitly ignored. Consider using 'ignore' to discard this value explicitly, e.g. 'expr |> ignore', or 'let' to bind the result to a name, e.g. 'let result = expr'."
+
+    [<Test>]
+    let ``Warn If Possible Property Setter``() =
+        CompilerAssert.TypeCheckSingleError
+            """
+type MyClass(property1 : int) =
+    member val Property1 = property1
+    member val Property2 = "" with get, set
+
+let x = MyClass(1)
+let y = "hello"
+
+let changeProperty() =
+    x.Property2 = "20"
+    y = "test"
+            """
+            FSharpErrorSeverity.Warning
+            20
+            (10, 5, 10, 23)
+            "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'. If you intended to set a value to a property, then use the '<-' operator e.g. 'x.Property2 <- expression'."

tests/fsharp/FSharpSuite.Tests.fsproj

@@ -35,6 +35,7 @@
     <Compile Include="Compiler\ErrorMessages\AccessOfTypeAbbreviationTests.fs" />
     <Compile Include="Compiler\ErrorMessages\ElseBranchHasWrongTypeTests.fs" />
     <Compile Include="Compiler\ErrorMessages\MissingElseBranch.fs" />
+    <Compile Include="Compiler\ErrorMessages\WarnExpressionTests.fs" />
     <Compile Include="Compiler\SourceTextTests.fs" />
     <Compile Include="Compiler\Language\AnonRecordTests.fs" />
     <Compile Include="Compiler\Language\SpanOptimizationTests.fs" />

tests/fsharpqa/Source/Warnings/env.lst

@@ -50,19 +50,8 @@
 	SOURCE=DowncastInsteadOfUpcast.fs # DowncastInsteadOfUpcast.fs
 	SOURCE=RuntimeTypeTestInPattern.fs # RuntimeTypeTestInPattern.fs
 	SOURCE=RuntimeTypeTestInPattern2.fs # RuntimeTypeTestInPattern2.fs
-	SOURCE=WarnIfExpressionResultUnused.fs # WarnIfExpressionResultUnused.fs
 	SOURCE=MemberHasMultiplePossibleDispatchSlots.fs # MemberHasMultiplePossibleDispatchSlots.fs
 	SOURCE=Repro1548.fs SCFLAGS="-r:Repro1548.dll"				# Repro1548.fs
-	SOURCE=WarnIfPossibleAssignment.fs
-	SOURCE=WarnIfPossibleAssignmentToMutable.fs
-	SOURCE=WarnIfPossibleDotNetPropertySetter.fs
-	SOURCE=DontWarnIfPropertyWithoutSetter.fs
-	SOURCE=WarnIfImplicitlyDiscarded.fs
-	SOURCE=WarnIfDiscardedInList.fs
-	SOURCE=WarnIfDiscardedInList2.fs
-	SOURCE=WarnIfDiscardedInList3.fs
-	SOURCE=WarnOnlyOnLastExpression.fs
-	SOURCE=WarnIfPossiblePropertySetter.fs
 	SOURCE=DoCannotHaveVisibilityDeclarations.fs
 	SOURCE=ModuleAbbreviationsArePrivate.fs
 	SOURCE=DontSuggestIntentionallyUnusedVariables.fs SCFLAGS="--vserrors" # DontSuggestIntentionallyUnusedVariables.fs