[JS] Support string.normalize()

src/Fable.Transforms/Replacements.fs

@@ -1616,6 +1616,34 @@ let strings (com: ICompiler) (ctx: Context) r t (i: CallInfo) (thisArg: Expr opt
             Helper.LibCall(com, "String", "concat", t, args, hasSpread = true, ?loc = r)
             |> Some
     | "CompareOrdinal", None, _ -> Helper.LibCall(com, "String", "compareOrdinal", t, args, ?loc = r) |> Some
+    | "Normalize", Some str, _ ->
+        match args with
+        | [] ->
+            Helper.InstanceCall(
+                str,
+                Naming.lowerFirst i.CompiledName,
+                t,
+                [ makeStrConst "NFC" ],
+                i.SignatureArgTypes,
+                genArgs = i.GenericArgs,
+                ?loc = r
+            )
+            |> Some
+        | [ NormalizationFormEnumValue normalizationForm ] ->
+            Helper.InstanceCall(
+                str,
+                Naming.lowerFirst i.CompiledName,
+                t,
+                [ makeStrConst normalizationForm ],
+                i.SignatureArgTypes,
+                genArgs = i.GenericArgs,
+                ?loc = r
+            )
+            |> Some
+        | _ ->
+            "Normalization expects an optional System.Text.NormalizationForm"
+            |> addErrorAndReturnNull com ctx.InlinePath r
+            |> Some
     | Patterns.SetContains implementedStringFunctions, thisArg, args ->
         Helper.LibCall(
             com,

src/Fable.Transforms/Transforms.Util.fs

@@ -823,6 +823,19 @@ module AST =
             Some()
         | _ -> None
 
+    let (|NormalizationFormEnumValue|_|) e =
+        match e with
+        | Expr.Value(
+            kind = NumberConstant(NumberValue.Int32 value,
+                                  NumberInfo.IsEnum({ FullName = "System.Text.NormalizationForm" }))) ->
+            match value with
+            | 1 -> Some "NFC"
+            | 2 -> Some "NFD"
+            | 5 -> Some "NFKC"
+            | 6 -> Some "NFKD"
+            | _ -> None
+        | _ -> None
+
     // TODO: Improve this, see https://github.com/fable-compiler/Fable/issues/1659#issuecomment-445071965
     // This is mainly used for inlining so a computation or a reference to a mutable value are understood
     // as a side effects too (because we don't want to duplicate or change the order of execution)

tests/Js/Main/StringTests.fs

@@ -831,12 +831,12 @@ let tests = testList "Strings" [
         for arg in args do
                 "abcd".EndsWith(fst arg)
                 |> equal (snd arg)
-    
+
     testCase "String.EndsWith with OrdinalIgnoreCase works" <| fun () ->
         let args = [("ab", false); ("CD", true); ("cd", true); ("bc", false); ("xabcd", false); ("abcd", true)]
         for arg in args do
                 "ABCD".EndsWith(fst arg, StringComparison.OrdinalIgnoreCase)
-                |> equal (snd arg)                
+                |> equal (snd arg)
 
     testCase "String.Trim works" <| fun () ->
         "   abc   ".Trim()
@@ -966,6 +966,15 @@ let tests = testList "Strings" [
         String.Concat(seq { yield "a"; yield "b"; yield "c" })
         |> equal "abc"
 
+    testCase "System.String.Normalize works" <| fun () ->
+        let name1 = "\u0041\u006d\u00e9\u006c\u0069\u0065";
+        let name2 = "\u0041\u006d\u0065\u0301\u006c\u0069\u0065";
+        notEqual name1 name2
+
+        let normalized1 = name1.Normalize System.Text.NormalizationForm.FormC
+        let normalized2 = name2.Normalize System.Text.NormalizationForm.FormC
+        equal normalized1 normalized2
+
     testCase "System.String.Join with long array works" <| fun () ->
         let n = 1_000_000
         let a = Array.init n (fun _i -> "a")