fix: do not include this argument when generating signature of a FunctionType

[converter][web]

Fix #118

Author: MangelMaxime

src/Glutinum.Converter/Transform.fs

@@ -437,6 +437,9 @@ let rec private transformType
         ({
             Parameters =
                 functionTypeInfo.Parameters
+                // TypeScript allows to annotate the `this` parameter but it is not actually part
+                // of the function signature that the user will call.
+                |> List.filter (fun parameter -> parameter.Name <> "this")
                 |> List.map (transformParameter context)
             ReturnType = transformType context functionTypeInfo.Type
         }

tests/specs/references/interfaces/methodWithCallbackAndThisAnnotated.d.ts

@@ -0,0 +1,3 @@
+interface Database {
+    run(sql: string, callback?: (this: string, err: Error | null) => void): this;
+}

tests/specs/references/interfaces/methodWithCallbackAndThisAnnotated.fsx

@@ -0,0 +1,14 @@
+module rec Glutinum
+
+open Fable.Core
+open Fable.Core.JsInterop
+open System
+
+[<AllowNullLiteral>]
+[<Interface>]
+type Database =
+    abstract member run: sql: string * ?callback: (Error option -> unit) -> Database
+
+(***)
+#r "nuget: Fable.Core"
+(***)