fix: use Exp.ifthenelse instead of Exp.match_ due to unicode

- Currently, due to the pattern matching with unicode issue, use the ifthenelse.
- It is planned to release the built-in unicode encode for source. rescript-lang/syntax#433
- As soon as the new built-in feature is released, will change to use pattern matching again.

Author: mununki

src/ppx/polyvariants.ml

@@ -34,20 +34,24 @@ let generateDecoderCase generatorSettings row =
   let { name; alias; rowField = { prf_desc } } = row in
   match prf_desc with
   | Rtag ({ txt; loc }, _, coreTypes) ->
+      let alias_name, loc, delimit = getStringFromExpression alias in
       let decoded =
         let resultantExp = Exp.variant txt None in
         [%expr Belt.Result.Ok [%e resultantExp]]
       in
 
-      let alias_name, loc, delimit = getStringFromExpression alias in
+      let if' =
+        Exp.apply (makeIdentExpr "=")
+          [
+            ( Asttypes.Nolabel,
+              Pconst_string (alias_name, Location.none, delimit) |> Exp.constant
+              |> fun v -> Some v |> Exp.construct (lid "Js.Json.JSONString") );
+            (Asttypes.Nolabel, [%expr tagged]);
+          ]
+      in
+      let then' = [%expr [%e decoded]] in
 
-      {
-        pc_lhs =
-          ( Pconst_string (alias_name, Location.none, delimit) |> Pat.constant
-          |> fun v -> Some v |> Pat.construct (lid "Js.Json.JSONString") );
-        pc_guard = None;
-        pc_rhs = [%expr [%e decoded]];
-      }
+      (if', then')
   | Rinherit coreType ->
       fail coreType.ptyp_loc "This syntax is not yet implemented by decco"
 
@@ -101,13 +105,14 @@ let generateCodecs ({ doEncode; doDecode } as generatorSettings) rowFields
     | false -> None
   in
 
-  let decoderDefaultCase =
-    {
-      pc_lhs = [%pat? _];
-      pc_guard = None;
-      pc_rhs = [%expr Decco.error "Invalid polyvariant constructor" v];
-    }
+  let rec makeIfThenElse cases =
+    match cases with
+    | [] -> [%expr Decco.error "Not matched" v]
+    | hd :: tl ->
+        let if_, then_ = hd in
+        Exp.ifthenelse if_ then_ (Some (makeIfThenElse tl))
   in
+
   let decoder =
     match not doDecode with
     | true -> None
@@ -117,9 +122,9 @@ let generateCodecs ({ doEncode; doDecode } as generatorSettings) rowFields
         | false ->
             let decoderSwitch =
               List.map (generateDecoderCase generatorSettings) parsedFields
-              |> fun l ->
-              l @ [ decoderDefaultCase ] |> Exp.match_ [%expr tagged]
+              |> makeIfThenElse
             in
+
             Some
               [%expr
                 fun v ->
@@ -129,4 +134,5 @@ let generateCodecs ({ doEncode; doDecode } as generatorSettings) rowFields
                       [%e decoderSwitch]
                   | _ -> Decco.error "Not a polyvariant" v])
   in
+
   (encoder, decoder)

src/ppx/variants.ml

@@ -24,20 +24,24 @@ let generateEncoderCase generatorSettings
 
 let generateDecoderCase generatorSettings
     { name; alias; constrDecl = { pcd_args; pcd_loc } } =
+  let alias_name, _, delimit = getStringFromExpression alias in
   let decoded =
     let ident = lid name in
     [%expr Belt.Result.Ok [%e Exp.construct ident None]]
   in
 
-  let alias_name, _, delimit = getStringFromExpression alias in
+  let if' =
+    Exp.apply (makeIdentExpr "=")
+      [
+        ( Asttypes.Nolabel,
+          Pconst_string (alias_name, Location.none, delimit) |> Exp.constant
+          |> fun v -> Some v |> Exp.construct (lid "Js.Json.JSONString") );
+        (Asttypes.Nolabel, [%expr tagged]);
+      ]
+  in
+  let then' = [%expr [%e decoded]] in
 
-  {
-    pc_lhs =
-      ( Pconst_string (alias_name, Location.none, delimit) |> Pat.constant
-      |> fun v -> Some v |> Pat.construct (lid "Js.Json.JSONString") );
-    pc_guard = None;
-    pc_rhs = [%expr [%e decoded]];
-  }
+  (if', then')
 
 let generateUnboxedDecode generatorSettings
     { pcd_name = { txt = name }; pcd_args; pcd_loc } =
@@ -81,12 +85,12 @@ let generateCodecs ({ doEncode; doDecode } as generatorSettings) constrDecls
     | false -> None
   in
 
-  let decoderDefaultCase =
-    {
-      pc_lhs = [%pat? _];
-      pc_guard = None;
-      pc_rhs = [%expr Decco.error "Invalid variant constructor" v];
-    }
+  let rec makeIfThenElse cases =
+    match cases with
+    | [] -> [%expr Decco.error "Not matched" v]
+    | hd :: tl ->
+        let if_, then_ = hd in
+        Exp.ifthenelse if_ then_ (Some (makeIfThenElse tl))
   in
 
   let decoder =
@@ -98,8 +102,7 @@ let generateCodecs ({ doEncode; doDecode } as generatorSettings) constrDecls
         | false ->
             let decoderSwitch =
               List.map (generateDecoderCase generatorSettings) parsedDecls
-              |> fun l ->
-              l @ [ decoderDefaultCase ] |> Exp.match_ [%expr tagged]
+              |> makeIfThenElse
             in
 
             Some

test/__tests__/test.js

@@ -5,10 +5,10 @@ open Expect
 describe("ppx_spice test", _ => {
   test("polymorphic variant encode", _ => {
     let sample1Encoded = #one->Sample1.t_encode
-    expect(sample1Encoded) |> toEqual("first"->Js.Json.string)
+    expect(sample1Encoded) |> toEqual(`하나`->Js.Json.string)
   })
   test("polymorphic variant decode", _ => {
-    let sample1Decoded = "second"->Js.Json.string->Sample1.t_decode
+    let sample1Decoded = `둘`->Js.Json.string->Sample1.t_decode
     expect(sample1Decoded) |> toEqual(Ok(#two))
   })
 
@@ -17,7 +17,7 @@ describe("ppx_spice test", _ => {
     expect(sample2Encoded) |> toEqual(`하나`->Js.Json.string)
   })
   test("variant decode", _ => {
-    let sample2Decoded = "둘"->Js.Json.string->Sample2.t_decode
+    let sample2Decoded = `둘`->Js.Json.string->Sample2.t_decode
     expect(sample2Decoded) |> toEqual(Ok(Sample2.Two))
   })
 })

test/__tests__/test.res

@@ -1,4 +1,2 @@
 @spice
-type t = [@spice.as("first") #one | @spice.as("second") #two]
-
-let sample1 = #one
+type t = [@spice.as(`하나`) #one | @spice.as(`둘`) #two]

test/src/sample1.js

@@ -1,4 +1,2 @@
 @spice
 type t = [#one | #two]
-
-let sample1: t