Better anonymous record error reporting

src/Compiler/Checking/CheckExpressions.fs

@@ -1796,6 +1796,14 @@ let FreshenAbstractSlot g amap m synTyparDecls absMethInfo =
     let retTyFromAbsSlot = retTy |> GetFSharpViewOfReturnType g |> instType typarInstFromAbsSlot
     typarsFromAbsSlotAreRigid, typarsFromAbsSlot, argTysFromAbsSlot, retTyFromAbsSlot
 
+let private CheckCopyUpdateSyntaxInAnonRecords sink (g: TcGlobals) ty (fldId: Ident) nenv ad =
+    match TryFindAnonRecdFieldOfType g ty fldId.idText with
+    | Some item ->
+        CallNameResolutionSink sink (fldId.idRange, nenv, item, emptyTyparInst, ItemOccurence.UseInType, ad)
+        error(Error(FSComp.SR.chkCopyUpdateSyntaxInAnonRecords(fldId.idText, fldId.idText), fldId.idRange))
+    | None ->
+        error(UndefinedName(0, FSComp.SR.undefinedNameRecordLabel, fldId, NoSuggestions))
+
 //-------------------------------------------------------------------------
 // Helpers to typecheck expressions and patterns
 //-------------------------------------------------------------------------
@@ -1813,10 +1821,14 @@ let BuildFieldMap (cenv: cenv) env isPartial ty (flds: ((Ident list * Ident) * '
         let allFields = flds |> List.map (fun ((_, ident), _) -> ident)
         flds
         |> List.choose (fun (fld, fldExpr) ->
+            let fldPath, fldId = fld
             try
-                let fldPath, fldId = fld
-                let frefSet = ResolveField cenv.tcSink cenv.nameResolver env.eNameResEnv ad ty fldPath fldId allFields
-                Some(fld, frefSet, fldExpr)
+                if isAnonRecdTy cenv.g ty || isStructAnonRecdTy cenv.g ty then
+                    CheckCopyUpdateSyntaxInAnonRecords cenv.tcSink cenv.g ty fldId env.eNameResEnv ad
+                    None
+                else
+                    let frefSet = ResolveField cenv.tcSink cenv.nameResolver env.eNameResEnv ad ty fldPath fldId allFields
+                    Some(fld, frefSet, fldExpr)
             with e ->
                 errorRecoveryNoRange e
                 None

src/Compiler/Checking/NameResolution.fs

@@ -3685,8 +3685,7 @@ let ResolveFieldPrim sink (ncenv: NameResolver) nenv ad ty (mp, id: Ident) allFi
                     error(ErrorWithSuggestions(errorText, m, id.idText, suggestLabels))
                 else
                     lookup()
-        | _ ->
-            lookup()
+        | ValueNone -> lookup()
     | _ ->
         let lid = (mp@[id])
         let tyconSearch ad () =

src/Compiler/FSComp.txt

@@ -1710,4 +1710,5 @@ featureAccessorFunctionShorthand,"underscore dot shorthand for accessor only fun
 3569,chkNotTailRecursive,"The member or function '%s' has the 'TailCallAttribute' attribute, but is not being used in a tail recursive way."
 3570,tcStaticBindingInExtrinsicAugmentation,"Static bindings cannot be added to extrinsic augmentations. Consider using a 'static member' instead."
 3571,pickleFsharpCoreBackwardsCompatible,"Newly added pickle state cannot be used in FSharp.Core, since it must be working in older compilers+tooling as well. The time window is at least 3 years after feature introduction. Violation: %s . Context: \n %s "
-3577,tcOverrideUsesMultipleArgumentsInsteadOfTuple,"This override takes a tuple instead of multiple arguments. Try to add an additional layer of parentheses at the method definition (e.g. 'member _.Foo((x, y))'), or remove parentheses at the abstract method declaration (e.g. 'abstract member Foo: 'a * 'b -> 'c')."
+3577,tcOverrideUsesMultipleArgumentsInsteadOfTuple,"This override takes a tuple instead of multiple arguments. Try to add an additional layer of parentheses at the method definition (e.g. 'member _.Foo((x, y))'), or remove parentheses at the abstract method declaration (e.g. 'abstract member Foo: 'a * 'b -> 'c')."
+3578,chkCopyUpdateSyntaxInAnonRecords,"'%s' is part of an anonymous record. Use {{| expr with %s = ... |}} instead."

tests/FSharp.Compiler.ComponentTests/Conformance/Types/RecordTypes/AnonymousRecords.fs

@@ -19,7 +19,18 @@ module AnonRecd =
         |> shouldFail
         |> withErrorCode 3522
         |> withMessage "The field 'A' appears multiple times in this record expression."
-
+
+    [<Fact>]
+    let ``Anonymous Records incomplete`` () =
+        Fsx """
+let x () : {| A: int; B: string  |} =  {| A = 123 |}
+"""
+        |> compile
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 1, Line 2, Col 40, Line 2, Col 53, "This anonymous record does not have enough fields. Add the missing fields [B].")
+        ]
+
     [<Fact>]
     let ``Anonymous Records with duplicate labels - Copy and update expression`` () =
         FSharp """
@@ -65,7 +76,55 @@ type ErrorResponse =
             Error 10, Line 7, Col 12, Line 7, Col 14, "Unexpected symbol '|}' in field declaration. Expected identifier or other token."
             Error 10, Line 10, Col 17, Line 10, Col 21, "Incomplete structured construct at or before this point in field declaration. Expected identifier or other token."
         ]
+
+    [<Fact>]
+    let ``Anonymous Record type annotation with with fields defined in a record`` () =
+        Fsx """
+type T = { ff : int }
 
+let t3 (t1: {| gu: string; ff: int |}) = { t1 with ff = 3 }
+        """
+        |> compile
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3578, Line 4, Col 52, Line 4, Col 54, "'ff' is part of an anonymous record. Use {| expr with ff = ... |} instead.")
+        ]
+
+    [<Fact>]
+    let ``This expression was expected to have an anonymous Record but has a record`` () =
+        Fsx """
+let t3 (t1: {| gu: string; ff: int |}) = { t1 with ff = 3 }
+        """
+        |> compile
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3578, Line 2, Col 52, Line 2, Col 54, "'ff' is part of an anonymous record. Use {| expr with ff = ... |} instead.")
+        ]
+
+    [<Fact>]
+    let ``This expression was expected to have an struct anonymous Record but has a record`` () =
+        Fsx """
+let t3 (t1: struct {| gu: string; ff: int |}) = { t1 with ff = 3 }
+        """
+        |> compile
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3578, Line 2, Col 59, Line 2, Col 61, "'ff' is part of an anonymous record. Use {| expr with ff = ... |} instead.")
+        ]
+
+    [<Fact>]
+    let ``This expression was expected to have an anonymous with various properties Record but has a record`` () =
+        Fsx """
+let f (r: {| A: int; C: int |}) = { r with A = 1; B = 2; C = 3 }
+        """
+        |> compile
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3578, Line 2, Col 44, Line 2, Col 45, "'A' is part of an anonymous record. Use {| expr with A = ... |} instead.")
+            (Error 39, Line 2, Col 51, Line 2, Col 52, "The record label 'B' is not defined.")
+            (Error 3578, Line 2, Col 58, Line 2, Col 59, "'C' is part of an anonymous record. Use {| expr with C = ... |} instead.")
+        ]
+
     [<Fact>]
     let ``Nested anonymous records where outer label = concatenated inner labels (see secondary issue reported in 6411)`` () =
         FSharp """
@@ -75,16 +134,3 @@ let x = {| abcd = {| ab = 4; cd = 1 |} |}
 """
         |> compile
         |> shouldSucceed
-
-    [<Fact>]
-    let ``Wrong update syntax`` () =
-        Fsx """
-let f (r: {| A: int |}) =
-    { r with A = 1 }
-"""
-        |> ignoreWarnings
-        |> compile
-        |> shouldFail
-        |> withDiagnostics [
-            (Error 39, Line 3, Col 14, Line 3, Col 15, "The record label 'A' is not defined.")
-        ]