Tooltips for types should show direct base types only

src/Compiler/Checking/NicePrint.fs

@@ -2028,6 +2028,7 @@ module TastDefinitionPrinting =
             GetIntrinsicConstructorInfosOfType infoReader m ty
             |> List.filter (fun minfo -> IsMethInfoAccessible amap m ad minfo && not minfo.IsClassConstructor && shouldShow minfo.ArbitraryValRef)
 
+        // Get base interfaces (either direct or all, depending on settings)
         let iimpls =
             if suppressInheritanceAndInterfacesForTyInSimplifiedDisplays g amap m ty then 
                 []
@@ -2036,7 +2037,11 @@ module TastDefinitionPrinting =
                 |> List.filter (fun (_, compgen, _) -> not compgen)
                 |> List.map p13
             else
-                GetImmediateInterfacesOfType SkipUnrefInterfaces.Yes g amap m ty
+                // Use immediate interfaces when showOnlyDirectBaseTypes=true, otherwise show all interfaces
+                if denv.showOnlyDirectBaseTypes then
+                    GetImmediateInterfacesOfType SkipUnrefInterfaces.Yes g amap m ty
+                else
+                    AllInterfacesOfType g amap m AllowMultiIntfInstantiations.Yes ty
 
         let iimplsLs =
             iimpls

src/Compiler/Service/ServiceDeclarationLists.fs

@@ -384,7 +384,9 @@ module DeclarationListHelpers =
                             // tooltips are space-constrained, so don't include xml doc comments
                             // on types/members. The doc comments for the actual member will still
                             // be shown in the tip.
-                            showDocumentation = false  }
+                            showDocumentation = false
+                            // only show direct base types in tooltips
+                            showOnlyDirectBaseTypes = true  }
             let layout = NicePrint.layoutTyconDefn denv infoReader ad m (* width *) tcref.Deref
             let layout = PrintUtilities.squashToWidth width layout
             let remarks = OutputFullName displayFullName pubpathOfTyconRef fullDisplayTextOfTyconRefAsLayout tcref

src/Compiler/TypedTree/TypedTreeOps.fs

@@ -3173,7 +3173,7 @@
     | Suffix
 
 [<NoEquality; NoComparison>]
 type DisplayEnv = 
     { includeStaticParametersInTypeNames: bool
       openTopPathsSorted: InterruptibleLazy<string list list>
       openTopPathsRaw: string list list
@@ -3193,13 +3193,14 @@
       showCsharpCodeAnalysisAttributes: bool
       showOverrides: bool
       showStaticallyResolvedTyparAnnotations: bool
       showNullnessAnnotations: bool option
       abbreviateAdditionalConstraints: bool
       showTyparDefaultConstraints: bool
       showDocumentation: bool
       shrinkOverloads: bool
       printVerboseSignatures: bool
       escapeKeywordNames: bool
+      showOnlyDirectBaseTypes: bool
       g: TcGlobals
       contextAccessibility: Accessibility
       generatedValueLayout : Val -> Layout option
@@ -3238,6 +3239,7 @@
         shrinkOverloads = true
         printVerboseSignatures = false
         escapeKeywordNames = false
+        showOnlyDirectBaseTypes = false
         g = tcGlobals
         contextAccessibility = taccessPublic
         generatedValueLayout = (fun _ -> None)
@@ -3267,7 +3269,8 @@
                showDocumentation = true
                shrinkOverloads = false
                escapeKeywordNames = true
-               includeStaticParametersInTypeNames = true }
+               includeStaticParametersInTypeNames = true
+               showOnlyDirectBaseTypes = false }
         denv.SetOpenPaths
             [ FSharpLib.RootPath
               FSharpLib.CorePath

src/Compiler/TypedTree/TypedTreeOps.fsi

@@ -1084,6 +1084,7 @@ type DisplayEnv =
         showCsharpCodeAnalysisAttributes: bool
         showOverrides: bool
         showStaticallyResolvedTyparAnnotations: bool
+        showOnlyDirectBaseTypes: bool
         showNullnessAnnotations: bool option
         abbreviateAdditionalConstraints: bool
         showTyparDefaultConstraints: bool

tests/FSharp.Compiler.Service.Tests/TooltipTests.fs

@@ -522,4 +522,106 @@ open System
 let doIt(myAction : Action<int>) = myAc{caret}tion.Invoke(42)
 """
     |> assertAndGetSingleToolTipText
-    |> Assert.shouldBeEquivalentTo ("""val myAction: Action<int>""" |> normalize)
+    |> Assert.shouldBeEquivalentTo ("""val myAction: Action<int>""" |> normalize)
+
+// Tests for direct interfaces in tooltips
+[<Fact>]
+let ``Tooltip for class with multiple direct interfaces shows all direct interfaces`` () =
+    let source = """
+module DirectInterfaces
+
+// Define multiple interfaces
+type IA =
+    abstract DoA: unit -> unit
+
+type IB =
+    abstract DoB: unit -> unit
+
+// Class implementing multiple interfaces
+type ClassWithMultipleInterfaces() =
+    interface IA with
+        member _.DoA() = ()
+    interface IB with
+        member _.DoB() = ()
+
+// Create an instance
+let obj = ClassWithMultipleInterfaces()
+"""
+    let checkResults = getCheckResults source Array.empty
+    let tooltip = checkResults.GetToolTip(12, 30, "type ClassWithMultipleInterfaces() =", [ "ClassWithMultipleInterfaces" ], FSharpTokenTag.Identifier)
+    let tooltipText = tooltip |> assertAndGetSingleToolTipText
+
+    // Verify both direct interfaces are shown
+    Assert.contains "inherit IA" tooltipText
+    Assert.contains "inherit IB" tooltipText
+
+[<Fact>]
+let ``Tooltip for class implementing interface chain shows only direct interface`` () =
+    let source = """
+module InterfaceChain
+
+// Define chained interfaces
+type IX =
+    abstract DoX: unit -> unit
+
+type IY =
+    inherit IX
+    abstract DoY: unit -> unit
+
+// Class implementing the most derived interface
+type ClassWithChainedInterface() =
+    interface IY with
+        member _.DoY() = ()
+        member _.DoX() = ()
+
+// Create an instance
+let obj = ClassWithChainedInterface()
+"""
+    let checkResults = getCheckResults source Array.empty
+    let tooltip = checkResults.GetToolTip(12, 31, "type ClassWithChainedInterface() =", [ "ClassWithChainedInterface" ], FSharpTokenTag.Identifier)
+    let tooltipText = tooltip |> assertAndGetSingleToolTipText
+
+    // Verify only direct interface is shown
+    Assert.contains "inherit IY" tooltipText
+    Assert.doesNotContain "inherit IX" tooltipText
+
+[<Fact>]
+let ``Tooltip for class with combined interface hierarchy shows only direct interfaces`` () =
+    let source = """
+module CombinedHierarchy
+
+// Base interfaces
+type IBase1 =
+    abstract DoBase1: unit -> unit
+
+type IBase2 =
+    abstract DoBase2: unit -> unit
+
+// Derived interfaces
+type IDerived1 =
+    inherit IBase1
+    abstract DoDerived1: unit -> unit
+
+type IDerived2 =
+    inherit IBase2
+    abstract DoDerived2: unit -> unit
+
+// Class implementing multiple interfaces, some in a chain
+type ComplexClass() =
+    interface IDerived1 with
+        member _.DoDerived1() = ()
+        member _.DoBase1() = ()
+    interface IBase2 with
+        member _.DoBase2() = ()
+
+// Create an instance
+let obj = ComplexClass()
+"""
+    let checkResults = getCheckResults source Array.empty
+    let tooltip = checkResults.GetToolTip(21, 19, "type ComplexClass() =", [ "ComplexClass" ], FSharpTokenTag.Identifier)
+    let tooltipText = tooltip |> assertAndGetSingleToolTipText
+
+    // Verify only direct interfaces are shown
+    Assert.contains "inherit IDerived1" tooltipText
+    Assert.contains "inherit IBase2" tooltipText
+    Assert.doesNotContain "inherit IBase1" tooltipText