Type checker: mark generated event tree nodes as synthetic

docs/release-notes/.FSharp.Compiler.Service/10.0.200.md

@@ -5,6 +5,7 @@
 * Fix `--preferreduilang` switch leaking into `fsi.CommandLineArgs` when positioned after script file ([PR #19151](https://github.com/dotnet/fsharp/pull/19151))
 * Fixed runtime crash when using interfaces with unimplemented static abstract members as constrained type arguments. ([Issue #19184](https://github.com/dotnet/fsharp/issues/19184))
 * Fix delegates with `[<OptionalArgument>]` and caller info attributes failing to compile. ([Issue #18868](https://github.com/dotnet/fsharp/issues/18868), [PR #19069](https://github.com/dotnet/fsharp/pull/19069))
+* Type checker: mark generated event tree nodes as synthetic ([PR #19213](https://github.com/dotnet/fsharp/pull/19213))
 
 ### Added
 

src/Compiler/Checking/Expressions/CheckExpressions.fs

@@ -2651,6 +2651,7 @@ module EventDeclarationNormalization =
             let MakeOne (prefix, target) =
                 let declPattern = RenameBindingPattern (fun s -> prefix + s) declPattern
                 let argName = "handler"
+                let mBinding = mBinding.MakeSynthetic()
 
                 // modify the rhs and argument data
                 let bindingRhs, valSynData =
@@ -2662,6 +2663,7 @@ module EventDeclarationNormalization =
                    match rhsExpr with
                    // Detect 'fun () -> e' which results from the compilation of a property getter
                    | SynExpr.Lambda (args=SynSimplePats.SimplePats(pats = []); body=trueRhsExpr; range=m) ->
+                       let m = m.MakeSynthetic()
                        let rhsExpr = mkSynApp1 (SynExpr.DotGet (SynExpr.Paren (trueRhsExpr, range0, None, m), range0, SynLongIdent([ident(target, m)], [], [None]), m)) (SynExpr.Ident (ident(argName, m))) m
 
                        // reconstitute rhsExpr

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

@@ -1287,6 +1287,18 @@ type T() =
 
         Assert.False hasPropertySymbols
 
+    [<Fact>]
+    let ``CLIEvent 01 - Synthetic range`` () =
+        let _, checkResults = getParseAndCheckResults """
+type T() =
+    [<CLIEvent>]
+    member this.Event = Event<int>().Publish
+"""
+        checkResults.GetAllUsesOfAllSymbolsInFile()
+        |> Seq.exists (fun symbolUse -> symbolUse.Symbol.DisplayNameCore = "handler")
+        |> shouldEqual false
+
+
 module Delegates =
     [<Fact>]
     let ``IL metadata`` () =