Unused analyzers: disable in VS when file has errors (#19892)

Author: auduchinok

docs/release-notes/.FSharp.Compiler.Service/11.0.100.md

@@ -88,6 +88,7 @@
 
 * Added warning FS3884 when a function or delegate value is used as an interpolated string argument. ([PR #19289](https://github.com/dotnet/fsharp/pull/19289))
 * Symbols: add ObsoleteDiagnosticInfo ([PR #19359](https://github.com/dotnet/fsharp/pull/19359))
+* FCS: add FSharpCheckFileResults.HasErrors ([PR #19892](https://github.com/dotnet/fsharp/pull/19892))
 * Add `#version;;` directive to F# Interactive to display version and environment information. ([Issue #13307](https://github.com/dotnet/fsharp/issues/13307), [PR #19332](https://github.com/dotnet/fsharp/pull/19332))
 * Debug: rework for expressions stepping ([PR #19894](https://github.com/dotnet/fsharp/pull/19894))
 

docs/release-notes/.VisualStudio/18.vNext.md

@@ -14,3 +14,4 @@
 ### Changed
 
 * Rename "inline hints" to "inlay hints" in VS options for consistency with industry terminology. ([PR #19318](https://github.com/dotnet/fsharp/pull/19318))
+* Unused analyzers: disable in VS when file has errors ([PR #19892](https://github.com/dotnet/fsharp/pull/19892))

src/Compiler/Service/FSharpCheckerResults.fs

@@ -3411,6 +3411,9 @@ type FSharpCheckFileResults
 
     member _.Diagnostics = errors
 
+    member _.HasErrors =
+        errors |> Array.exists (fun d -> d.Severity = FSharpDiagnosticSeverity.Error)
+
     member _.HasFullTypeCheckInfo = details.IsSome
 
     member _.TryGetCurrentTcImports() =

src/Compiler/Service/FSharpCheckerResults.fsi

@@ -253,6 +253,8 @@ type public FSharpCheckFileResults =
     /// The errors returned by parsing a source file.
     member Diagnostics: FSharpDiagnostic[]
 
+    member HasErrors: bool
+
     /// Get a view of the contents of the assembly up to and including the file just checked
     member PartialAssemblySignature: FSharpAssemblySignature
 

tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.bsl

@@ -2085,8 +2085,10 @@ FSharp.Compiler.CodeAnalysis.FSharpCheckFileAnswer: Int32 GetHashCode(System.Col
 FSharp.Compiler.CodeAnalysis.FSharpCheckFileAnswer: Int32 Tag
 FSharp.Compiler.CodeAnalysis.FSharpCheckFileAnswer: Int32 get_Tag()
 FSharp.Compiler.CodeAnalysis.FSharpCheckFileAnswer: System.String ToString()
+FSharp.Compiler.CodeAnalysis.FSharpCheckFileResults: Boolean HasErrors
 FSharp.Compiler.CodeAnalysis.FSharpCheckFileResults: Boolean HasFullTypeCheckInfo
 FSharp.Compiler.CodeAnalysis.FSharpCheckFileResults: Boolean IsRelativeNameResolvableFromSymbol(FSharp.Compiler.Text.Position, Microsoft.FSharp.Collections.FSharpList`1[System.String], FSharp.Compiler.Symbols.FSharpSymbol)
+FSharp.Compiler.CodeAnalysis.FSharpCheckFileResults: Boolean get_HasErrors()
 FSharp.Compiler.CodeAnalysis.FSharpCheckFileResults: Boolean get_HasFullTypeCheckInfo()
 FSharp.Compiler.CodeAnalysis.FSharpCheckFileResults: FSharp.Compiler.CodeAnalysis.FSharpProjectContext ProjectContext
 FSharp.Compiler.CodeAnalysis.FSharpCheckFileResults: FSharp.Compiler.CodeAnalysis.FSharpProjectContext get_ProjectContext()

vsintegration/src/FSharp.Editor/Diagnostics/UnusedDeclarationsAnalyzer.fs

@@ -33,11 +33,15 @@ type internal UnusedDeclarationsAnalyzer [<ImportingConstructor>] () =
 
                     let! unusedRanges = UnusedDeclarations.getUnusedDeclarations (checkResults, (isScriptFile document.FilePath))
 
-                    let! sourceText = document.GetTextAsync()
-
-                    return
-                        unusedRanges
-                        |> Seq.map (fun m -> Diagnostic.Create(descriptor, RoslynHelpers.RangeToLocation(m, sourceText, document.FilePath)))
-                        |> Seq.toImmutableArray
+                    if checkResults.HasErrors then
+                        return ImmutableArray.Empty
+                    else
+                        let! sourceText = document.GetTextAsync()
+
+                        return
+                            unusedRanges
+                            |> Seq.map (fun m ->
+                                Diagnostic.Create(descriptor, RoslynHelpers.RangeToLocation(m, sourceText, document.FilePath)))
+                            |> Seq.toImmutableArray
                 }
                 |> CancellableTask.start cancellationToken

vsintegration/src/FSharp.Editor/Diagnostics/UnusedOpensDiagnosticAnalyzer.fs

@@ -29,10 +29,13 @@ type internal UnusedOpensDiagnosticAnalyzer [<ImportingConstructor>] () =
 
                 let! _, checkResults = document.GetFSharpParseAndCheckResultsAsync(nameof UnusedOpensDiagnosticAnalyzer)
 
-                let! unusedOpens =
-                    UnusedOpens.getUnusedOpens (checkResults, (fun lineNumber -> sourceText.Lines[Line.toZ lineNumber].ToString()))
+                if checkResults.HasErrors then
+                    return ValueNone
+                else
+                    let! unusedOpens =
+                        UnusedOpens.getUnusedOpens (checkResults, (fun lineNumber -> sourceText.Lines[Line.toZ lineNumber].ToString()))
 
-                return (ValueSome unusedOpens)
+                    return (ValueSome unusedOpens)
         }
 
     interface IFSharpUnusedOpensDiagnosticAnalyzer with