Be very literal about the LangVersion string (#7895)

* Be very literal about the LangVersion string

* Skip timing test

Author: cartermp

src/fsharp/LanguageFeatures.fs

@@ -29,9 +29,8 @@ type LanguageFeature =
     | ImplicitYield = 7
     | OpenStaticClasses = 8
 
-
 /// LanguageVersion management
-type LanguageVersion (specifiedVersion) =
+type LanguageVersion (specifiedVersionAsString) =
 
     // When we increment language versions here preview is higher than current RTM version
     static let languageVersion46 = 4.6m
@@ -44,30 +43,34 @@ type LanguageVersion (specifiedVersion) =
     static let validOptions = [| "preview"; "default"; "latest"; "latestmajor" |]
     static let languageVersions = set [| languageVersion46; languageVersion47 |]
 
-    static let features = dict [|
-        // Add new LanguageVersions here ...
-        LanguageFeature.LanguageVersion46, languageVersion46
-        LanguageFeature.LanguageVersion47, languageVersion47
-        LanguageFeature.PreviewVersion, previewVersion
-        LanguageFeature.SingleUnderscorePattern, languageVersion47
-        LanguageFeature.WildCardInForLoop, languageVersion47
-        LanguageFeature.RelaxWhitespace, languageVersion47
-        LanguageFeature.NameOf, previewVersion
-        LanguageFeature.ImplicitYield, languageVersion47
-        LanguageFeature.OpenStaticClasses, previewVersion
-        |]
+    static let features =
+        dict [
+            // Add new LanguageVersions here ...
+            LanguageFeature.LanguageVersion46, languageVersion46
+            LanguageFeature.LanguageVersion47, languageVersion47
+            LanguageFeature.PreviewVersion, previewVersion
+        
+            // F# 4.7
+            LanguageFeature.SingleUnderscorePattern, languageVersion47
+            LanguageFeature.WildCardInForLoop, languageVersion47
+            LanguageFeature.RelaxWhitespace, languageVersion47
+            LanguageFeature.ImplicitYield, languageVersion47
+
+            // Add new Language Features here...
+            LanguageFeature.NameOf, previewVersion
+            LanguageFeature.OpenStaticClasses, previewVersion
+        ]
 
     let specified =
-        match specifiedVersion with
+        match specifiedVersionAsString with
         | "?" -> 0m
         | "preview" -> previewVersion
         | "default" -> defaultVersion
         | "latest" -> latestVersion
         | "latestmajor" -> latestMajorVersion
-        | _ ->
-            match Decimal.TryParse(specifiedVersion) with
-            | true, v -> v
-            | _ -> 0m
+        | "4.6" -> languageVersion46
+        | "4.7" -> languageVersion47
+        | _ -> 0m
 
     /// Check if this feature is supported by the selected langversion
     member __.SupportsFeature featureId =
@@ -79,10 +82,7 @@ type LanguageVersion (specifiedVersion) =
     member __.ContainsVersion version =
         match version with
         | "?" | "preview" | "default" | "latest" | "latestmajor" -> true
-        | _ -> 
-            match Decimal.TryParse(specifiedVersion) with
-            | true, v -> languageVersions.Contains v
-            | _ -> false
+        | _ -> languageVersions.Contains specified
 
     /// Get a list of valid strings for help text
     member __.ValidOptions = validOptions

tests/FSharp.Compiler.Private.Scripting.UnitTests/FSharpScriptTests.fs

@@ -72,3 +72,43 @@ type InteractiveTests() =
         let _result, errors = script.Eval(sprintf "#r \"%s\"" testAssembly)
         Assert.AreEqual(1, errors.Length)
         Assert.False(foundAssemblyReference)
+
+    [<Test>]
+    member _.``Compilation errors report a specific exception``() =
+        use script = new FSharpScript()
+        let result, _errors = script.Eval("abc")
+        match result with
+        | Ok(_) -> Assert.Fail("expected a failure")
+        | Error(ex) -> Assert.IsInstanceOf<FsiCompilationException>(ex)
+
+    [<Test>]
+    member _.``Runtime exceptions are propagated``() =
+        use script = new FSharpScript()
+        let result, errors = script.Eval("System.IO.File.ReadAllText(\"not-a-file-path-that-can-be-found-on-disk.txt\")")
+        Assert.IsEmpty(errors)
+        match result with
+        | Ok(_) -> Assert.Fail("expected a failure")
+        | Error(ex) -> Assert.IsInstanceOf<FileNotFoundException>(ex)
+
+    [<Test; Ignore("This timing test fails in different environments. Skipping so that we don't assume an arbitrary CI environment has enough compute/etc. for what we need here.")>]
+    member _.``Evaluation can be cancelled``() =
+        use script = new FSharpScript()
+        let sleepTime = 10000
+        let mutable result = None
+        let mutable wasCancelled = false
+        use tokenSource = new CancellationTokenSource()
+        let eval () =
+            try
+                result <- Some(script.Eval(sprintf "System.Threading.Thread.Sleep(%d)\n2" sleepTime, tokenSource.Token))
+                // if execution gets here (which it shouldn't), the value `2` will be returned
+            with
+            | :? OperationCanceledException -> wasCancelled <- true
+        let sw = Stopwatch.StartNew()
+        let evalTask = Task.Run(eval)
+        // cancel and wait for finish
+        tokenSource.Cancel()
+        evalTask.GetAwaiter().GetResult()
+        // ensure we cancelled and didn't complete the sleep or evaluation
+        Assert.True(wasCancelled)
+        Assert.LessOrEqual(sw.ElapsedMilliseconds, sleepTime)
+        Assert.AreEqual(None, result)