[TS] Added support for erasableSyntaxOnly in TypeScript (#4235)

Author: ncave

.vscode/launch.json

@@ -263,7 +263,7 @@
         "--outDir", "${workspaceRoot}/../fable-test",
         "--fableLib", "${workspaceRoot}/temp/fable-library-rust",
         "--exclude", "Fable.Core",
-        "--lang", "Rust",
+        "--lang", "TypeScript",
         "--noCache",
         "--noParallelTypeCheck"
       ],

src/Fable.Cli/CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+* [TS] Added support for `erasableSyntaxOnly` in TypeScript (by @ncave)
 * [All] Added some default `System` exception implementations (by @ncave)
 * [All] Added `ofOption`/`toOption`/`ofValueOption`/`toValueOption` (by @ncave)
 * [Python] Added `Decorate` attribute to add Python decorators to classes (by @dbrattli)

src/Fable.Compiler/CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+* [TS] Added support for `erasableSyntaxOnly` in TypeScript (by @ncave)
 * [All] Added some default `System` exception implementations (by @ncave)
 * [All] Added `ofOption`/`toOption`/`ofValueOption`/`toValueOption` (by @ncave)
 * [Python] Added `Decorate` attribute to add Python decorators to classes (by @dbrattli)

src/Fable.Transforms/Fable2Babel.fs

@@ -609,6 +609,8 @@ module Annotation =
         | Fable.String -> StringTypeAnnotation
         | Fable.Regex -> makeAliasTypeAnnotation com ctx "RegExp"
         | Fable.Number(BigInt, _) -> makeAliasTypeAnnotation com ctx "bigint"
+        | Fable.Number(Int32, Fable.NumberInfo.IsEnum ent) when ent.FullName = "System.DateTimeKind" ->
+            makeFableLibImportTypeAnnotation com ctx [] "Util" "DateTimeKind"
         | Fable.Number(kind, _) -> makeNumericTypeAnnotation com ctx kind
         | Fable.Nullable(genArg, isStruct) -> makeNullableTypeAnnotation com ctx isStruct genArg
         | Fable.Option(genArg, isStruct) -> makeOptionTypeAnnotation com ctx isStruct genArg
@@ -1462,7 +1464,7 @@ module Util =
         match e, typ with
         | Literal(NumericLiteral(_)), _ -> e
         // TODO: Unsigned ints seem to cause problems, should we check only Int32 here?
-        | _, Fable.Number((Int8 | Int16 | Int32), _) ->
+        | _, Fable.Number((Int8 | Int16 | Int32), Fable.NumberInfo.Empty) ->
             Expression.binaryExpression (BinaryOrBitwise, e, Expression.numericLiteral (0.))
         | _ -> e
 
@@ -3402,10 +3404,10 @@ but thanks to the optimisation done below we get
                 |> Seq.choose (fun ifc ->
                     match ifc.Entity.FullName with
                     // Discard non-generic versions of IEquatable & IComparable
-                    | "System.IEquatable"
+                    | Types.iequatable
                     | Types.iStructuralEquatable
                     | Types.iequalityComparer
-                    | "System.IComparable"
+                    | Types.icomparable
                     | Types.iStructuralComparable
                     | Types.ienumerable
                     | Types.ienumerator -> None
@@ -3812,10 +3814,37 @@ but thanks to the optimisation done below we get
                     Parameter.parameter ("fields", typeAnnotation = fieldsArgTa)
                 |]
 
-            let consArgsModifiers = [| Readonly; Readonly |]
+            let consArgsModifiers = [||]
 
-            let consBody = BlockStatement [| callSuperAsStatement [] |]
-            let classMembers = Array.append [| cases |] classMembers
+            let consBody =
+                BlockStatement
+                    [|
+                        callSuperAsStatement []
+                        yield!
+                            [ "tag"; "fields" ]
+                            |> List.map (fun name ->
+                                let left = get None thisExpr name
+                                let right = Expression.identifier (name)
+                                assign None left right |> ExpressionStatement
+                            )
+                    |]
+
+            let classMembers =
+                [|
+                    ClassMember.classProperty (
+                        Expression.identifier "tag",
+                        typeAnnotation = tagArgTa,
+                        accessModifier = Readonly
+                    )
+
+                    ClassMember.classProperty (
+                        Expression.identifier "fields",
+                        typeAnnotation = fieldsArgTa,
+                        accessModifier = Readonly
+                    )
+                    cases
+                    yield! classMembers
+                |]
 
             let unionConsTypeParams =
                 Some(

src/Fable.Transforms/Replacements.fs

@@ -3148,13 +3148,9 @@ let dateTime (com: ICompiler) (ctx: Context) r t (i: CallInfo) (thisArg: Expr op
     | "ToString" ->
         Helper.LibCall(com, "Date", "toString", t, args, i.SignatureArgTypes, ?thisArg = thisArg, ?loc = r)
         |> Some
-    // | "get_Kind" ->
-    //     Helper.LibCall(com, moduleName, "kind", t, [ thisArg.Value ], [ thisArg.Value.Type ], ?loc = r)
-    //     |> Some
-    //     let y = DateTime.Now.UtcTicks
-    //     let x = DateTimeOffset.Now.UtcTicks
-    //     failwith "Not implemented"
-
+    | "get_Kind" ->
+        Helper.LibCall(com, "Date", "getKind", t, [ thisArg.Value ], [ thisArg.Value.Type ], ?loc = r)
+        |> Some
     | "get_Ticks" ->
         Helper.LibCall(com, "Date", "getTicks", t, [ thisArg.Value ], [ thisArg.Value.Type ], ?loc = r)
         |> Some

src/Fable.Transforms/Transforms.Util.fs

@@ -420,6 +420,9 @@ module Types =
     [<Literal>]
     let icomparableGeneric = "System.IComparable`1"
 
+    [<Literal>]
+    let iequatable = "System.IEquatable"
+
     [<Literal>]
     let icomparable = "System.IComparable"
 

src/fable-library-ts/Char.ts

@@ -33,38 +33,40 @@ function getCategoryFunc() {
   };
 }
 
-export const enum UnicodeCategory {
-  UppercaseLetter,
-  LowercaseLetter,
-  TitlecaseLetter,
-  ModifierLetter,
-  OtherLetter,
-  NonSpacingMark,
-  SpacingCombiningMark,
-  EnclosingMark,
-  DecimalDigitNumber,
-  LetterNumber,
-  OtherNumber,
-  SpaceSeparator,
-  LineSeparator,
-  ParagraphSeparator,
-  Control,
-  Format,
-  Surrogate,
-  PrivateUse,
-  ConnectorPunctuation,
-  DashPunctuation,
-  OpenPunctuation,
-  ClosePunctuation,
-  InitialQuotePunctuation,
-  FinalQuotePunctuation,
-  OtherPunctuation,
-  MathSymbol,
-  CurrencySymbol,
-  ModifierSymbol,
-  OtherSymbol,
-  OtherNotAssigned,
-}
+export const UnicodeCategory = {
+  UppercaseLetter: 0,
+  LowercaseLetter: 1,
+  TitlecaseLetter: 2,
+  ModifierLetter: 3,
+  OtherLetter: 4,
+  NonSpacingMark: 5,
+  SpacingCombiningMark: 6,
+  EnclosingMark: 7,
+  DecimalDigitNumber: 8,
+  LetterNumber: 9,
+  OtherNumber: 10,
+  SpaceSeparator: 11,
+  LineSeparator: 12,
+  ParagraphSeparator: 13,
+  Control: 14,
+  Format: 15,
+  Surrogate: 16,
+  PrivateUse: 17,
+  ConnectorPunctuation: 18,
+  DashPunctuation: 19,
+  OpenPunctuation: 20,
+  ClosePunctuation: 21,
+  InitialQuotePunctuation: 22,
+  FinalQuotePunctuation: 23,
+  OtherPunctuation: 24,
+  MathSymbol: 25,
+  CurrencySymbol: 26,
+  ModifierSymbol: 27,
+  OtherSymbol: 28,
+  OtherNotAssigned: 29,
+} as const;
+
+export type UnicodeCategory = typeof UnicodeCategory[keyof typeof UnicodeCategory];
 
 const isControlMask = 1 << UnicodeCategory.Control;
 const isDigitMask = 1 << UnicodeCategory.DecimalDigitNumber;