feat: add support for optional type

[converter]

Fix #68

Author: MangelMaxime

CHANGELOG.md

@@ -187,6 +187,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
     SettingsContainer.#privateField = $0"""
     ```
 
+* Add support for optional type
+
+    ```ts
+    export type LatLngTuple = [number, number, number?];
+    ```
+
+    ```fs
+    type LatLngTuple = float * float * float option
+    ```
+
 ### Changed
 
 * Replace `Boolean` with `bool`

src/Glutinum.Converter/GlueAST.fs

@@ -209,6 +209,7 @@ type GlueType =
     | TupleType of GlueType list
     | IntersectionType of GlueMember list
     | TypeLiteral of GlueTypeLiteral
+    | OptionalType of GlueType
 
     member this.Name =
         match this with
@@ -243,4 +244,5 @@ type GlueType =
         | Partial _
         | FunctionType _
         | TupleType _
+        | OptionalType _ // TODO: Should we take the name of the underlying type and add option to it?
         | Discard -> "obj"

src/Glutinum.Converter/Reader/TypeNode.fs

@@ -309,6 +309,11 @@ let readTypeNode
 
         reader.ReadTypeNode parenthesizedTypeNode.``type``
 
+    | Ts.SyntaxKind.OptionalType ->
+        let optionalTypeNode = typeNode :?> Ts.OptionalTypeNode
+
+        reader.ReadTypeNode optionalTypeNode.``type`` |> GlueType.OptionalType
+
     | _ ->
         generateReaderError
             "type node"

src/Glutinum.Converter/Transform.fs

@@ -126,6 +126,9 @@ let rec private transformType
     | GlueType.Primitive primitiveInfo ->
         transformPrimitive primitiveInfo |> FSharpType.Primitive
 
+    | GlueType.OptionalType glueType ->
+        transformType context glueType |> FSharpType.Option
+
     | GlueType.ThisType typeName -> FSharpType.ThisType typeName
 
     | GlueType.TupleType glueTypes -> transformTupleType context glueTypes
@@ -178,7 +181,7 @@ let rec private transformType
         |> FSharpType.TypeReference
 
     | GlueType.Array glueType ->
-        (transformType context) glueType |> FSharpType.ResizeArray
+        transformType context glueType |> FSharpType.ResizeArray
 
     | GlueType.ClassDeclaration classDeclaration ->
         ({
@@ -198,7 +201,7 @@ let rec private transformType
                 functionTypeInfo.Parameters
                 |> List.map (transformParameter context)
             TypeArguments = []
-            ReturnType = (transformType context) functionTypeInfo.Type
+            ReturnType = transformType context functionTypeInfo.Type
         }
         : FSharpFunctionType)
         |> FSharpType.Function
@@ -328,7 +331,7 @@ let private transformExports
                         info.Parameters |> List.map (transformParameter context)
                     TypeParameters =
                         transformTypeParameters context info.TypeParameters
-                    Type = (transformType context) info.Type
+                    Type = transformType context info.Type
                     IsOptional = false
                     IsStatic = true
                     Accessor = None
@@ -1208,7 +1211,8 @@ let private transformTypeAliasDeclaration
     | GlueType.Discard
     | GlueType.FunctionDeclaration _
     | GlueType.ThisType _
-    | GlueType.Variable _ -> FSharpType.Discard
+    | GlueType.Variable _
+    | GlueType.OptionalType _ -> FSharpType.Discard
 
 let private transformModuleDeclaration
     (moduleDeclaration: GlueModuleDeclaration)
@@ -1295,6 +1299,7 @@ let rec private transformToFsharp
         | GlueType.TupleType _
         | GlueType.IntersectionType _
         | GlueType.TypeLiteral _
+        | GlueType.OptionalType _
         | GlueType.ThisType _ -> FSharpType.Discard
     )
 

src/Glutinum.Web/Pages/Editors.GlueAST.GlueASTViewer.fs

@@ -164,6 +164,12 @@ type GlueASTViewer =
                 ]
                 context
 
+        | GlueType.OptionalType optionalType ->
+            ASTViewer.renderNode
+                "OptionalType"
+                [ GlueASTViewer.Type optionalType ]
+                context
+
         | GlueType.Interface interfaceInfo ->
             ASTViewer.renderNode
                 "Interface"

tests/specs/references/tupleType/withOptionalType.d.ts

@@ -0,0 +1 @@
+export type LatLngTuple = [number, number, number?];

tests/specs/references/tupleType/withOptionalType.fsx

@@ -0,0 +1,12 @@
+module rec Glutinum
+
+open Fable.Core
+open Fable.Core.JsInterop
+open System
+
+type LatLngTuple =
+    float * float * float option
+
+(***)
+#r "nuget: Fable.Core"
+(***)