Improve error message and tests

src/Compiler/Checking/CheckExpressions.fs

@@ -7033,6 +7033,10 @@ and TcObjectExpr (cenv: cenv) env tpenv (objTy, realObjTy, argopt, binds, extraI
         // 2. check usage conditions
         overridesAndVirts |> List.iter (fun (m, implTy, dispatchSlots, dispatchSlotsKeyed, availPriorOverrides, overrides) ->
             let overrideSpecs = overrides |> List.map fst
+            let hasStaticMembers = dispatchSlots |> List.exists (fun reqdSlot -> not reqdSlot.MethodInfo.IsInstance)
+
+            if hasStaticMembers then
+                errorR(Error(FSComp.SR.chkStaticMembersOnObjectExpressions(), mObjTy))
 
             DispatchSlotChecking.CheckOverridesAreAllUsedOnce (env.DisplayEnv, g, cenv.infoReader, true, implTy, dispatchSlotsKeyed, availPriorOverrides, overrideSpecs)
 

src/Compiler/FSComp.txt

@@ -1730,4 +1730,4 @@ featureUnmanagedConstraintCsharpInterop,"Interop between C#'s and F#'s unmanaged
 3584,tcDotLambdaAtNotSupportedExpression,"Shorthand lambda syntax is only supported for atomic expressions, such as method, property, field or indexer on the implied '_' argument. For example: 'let f = _.Length'."
 3855,tcNoStaticMemberFoundForOverride,"No static abstract member was found that corresponds to this override"
 3859,tcNoStaticPropertyFoundForOverride,"No static abstract property was found that corresponds to this override"
-3860,chkStaticMembersOnObjectExpressions,"Static members are not allowed in object expressions."
+3860,chkStaticMembersOnObjectExpressions,"Object expressions cannot implement interfaces with static abstract members or declare static members."

tests/FSharp.Compiler.ComponentTests/Conformance/Expressions/ObjectExpressions/ObjectExpressions.fs

@@ -183,6 +183,7 @@ let objExpr =
          |> typecheck
          |> shouldFail
          |> withDiagnostics [
+            (Error 3860, Line 7, Col 11, Line 7, Col 21, "Object expressions cannot implement interfaces with static abstract members or declare static members.")
             (Error 17, Line 8, Col 18, Line 8, Col 25, "The member 'Execute: unit -> unit' does not have the correct type to override the corresponding abstract method. Non-static member is expected.");
             (Error 783, Line 7, Col 11, Line 7, Col 21, "At least one override did not correctly implement its corresponding abstract member")
          ]
@@ -205,7 +206,8 @@ let _ =
          |> typecheck
          |> shouldFail
          |> withDiagnostics [
-             (Error 3860, Line 8, Col 23, Line 8, Col 30, "Static members are not allowed in object expressions.")
+            (Error 3860, Line 7, Col 11, Line 7, Col 21, "Object expressions cannot implement interfaces with static abstract members or declare static members.");
+            (Error 3860, Line 8, Col 23, Line 8, Col 30, "Object expressions cannot implement interfaces with static abstract members or declare static members.")
          ]
 
     [<FactForNETCOREAPP>]
@@ -226,8 +228,9 @@ let _ =
          |> typecheck
          |> shouldFail
          |> withDiagnostics [
-            (Error 3860, Line 8, Col 23, Line 8, Col 30, "Static members are not allowed in object expressions.");
-            (Error 3860, Line 9, Col 23, Line 9, Col 31, "Static members are not allowed in object expressions.")
+            (Error 3860, Line 7, Col 11, Line 7, Col 21, "Object expressions cannot implement interfaces with static abstract members or declare static members.")
+            (Error 3860, Line 8, Col 23, Line 8, Col 30, "Object expressions cannot implement interfaces with static abstract members or declare static members.");
+            (Error 3860, Line 9, Col 23, Line 9, Col 31, "Object expressions cannot implement interfaces with static abstract members or declare static members.")
          ]
 
     [<FactForNETCOREAPP>]
@@ -252,8 +255,9 @@ let _ =
          |> typecheck
          |> shouldFail
          |> withDiagnostics [
-            (Error 3860, Line 10, Col 23, Line 10, Col 30, "Static members are not allowed in object expressions.");
-            (Error 3860, Line 12, Col 23, Line 12, Col 31, "Static members are not allowed in object expressions.");
+            (Error 3860, Line 9, Col 11, Line 9, Col 21, "Object expressions cannot implement interfaces with static abstract members or declare static members.")
+            (Error 3860, Line 10, Col 23, Line 10, Col 30, "Object expressions cannot implement interfaces with static abstract members or declare static members.");
+            (Error 3860, Line 12, Col 23, Line 12, Col 31, "Object expressions cannot implement interfaces with static abstract members or declare static members.");
          ]
 
     [<FactForNETCOREAPP>]
@@ -274,7 +278,8 @@ consoleLogger.Log("Hello World")
          |> withOptions [ "--nowarn:3536" ; "--nowarn:3535" ]
          |> withLangVersion80
          |> compile
-         |> shouldSucceed
+         |> shouldFail
+         |> withSingleDiagnostic (Error 3860, Line 7, Col 11, Line 7, Col 18, "Object expressions cannot implement interfaces with static abstract members or declare static members.")
 
     [<FactForNETCOREAPP>]
     let ``No error when implementing only instance members from IWSAM(Interface attribute) in an object expression`` () =
@@ -295,7 +300,8 @@ consoleLogger.Log("Hello World")
          |> withOptions [ "--nowarn:3536" ; "--nowarn:3535" ]
          |> withLangVersion80
          |> compile
-         |> shouldSucceed
+         |> shouldFail
+         |> withSingleDiagnostic (Error 3860, Line 8, Col 11, Line 8, Col 18, "Object expressions cannot implement interfaces with static abstract members or declare static members.")
 
     [<FactForNETCOREAPP>]
     let ``No error when implementing only instance members from a type(Interface attribute) in an object expression`` () =
@@ -314,5 +320,5 @@ let consoleLogger =
 consoleLogger.Log("Hello World")
         """
          |> withLangVersion80
-         |> compile
+         |> compileExeAndRun
          |> shouldSucceed