Fix rendering of array types

v3/internal/parser/render/create.go

@@ -40,11 +40,11 @@ func (m *module) NeedsCreate(typ types.Type) bool {
  return m.NeedsCreate(t.Underlying())
  }
 
- case *types.Array, *types.Map, *types.Slice:
- return true
+ case *types.Array, *types.Pointer:
+ return m.NeedsCreate(typ.(interface{ Elem() types.Type }).Elem())
 
- case *types.Pointer:
- return m.NeedsCreate(t.Elem())
+ case *types.Map, *types.Slice:
+ return true
 
  case *types.Struct:
  info := m.collector.Struct(t)
@@ -88,16 +88,19 @@ func (m *module) JSCreateWithParams(typ types.Type, params string) string {
  case *types.Alias:
  return m.JSCreateWithParams(types.Unalias(typ), params)
 
- case *types.Array:
+ case *types.Array, *types.Pointer:
  pp, ok := m.postponedCreates.At(typ).(*postponed)
- if !ok {
- m.JSCreateWithParams(t.Elem(), params)
+ if ok {
+ return fmt.Sprintf("$$createType%d%s", pp.index, params)
+ }
+
+ createElement := m.JSCreateWithParams(typ.(interface{ Elem() types.Type }).Elem(), params)
+ if createElement != "$Create.Any" {
  pp = &postponed{m.postponedCreates.Len(), params}
  m.postponedCreates.Set(typ, pp)
+ return fmt.Sprintf("$$createType%d%s", pp.index, params)
  }
 
- return fmt.Sprintf("$$createType%d%s", pp.index, params)
-
  case *types.Map:
  pp, ok := m.postponedCreates.At(typ).(*postponed)
  if !ok {
@@ -136,20 +139,11 @@ func (m *module) JSCreateWithParams(typ types.Type, params string) string {
 
  return fmt.Sprintf("$$createType%d%s", pp.index, params)
 
- case *types.Pointer:
- pp, ok := m.postponedCreates.At(typ).(*postponed)
- if ok {
- return fmt.Sprintf("$$createType%d%s", pp.index, params)
- }
-
- createElement := m.JSCreateWithParams(t.Elem(), params)
- if createElement != "$Create.Any" {
- pp = &postponed{m.postponedCreates.Len(), params}
- m.postponedCreates.Set(typ, pp)
- return fmt.Sprintf("$$createType%d%s", pp.index, params)
+ case *types.Slice:
+ if types.Identical(typ, typeByteSlice) {
+ return "$Create.ByteSlice"
  }
 
- case *types.Slice:
  pp, ok := m.postponedCreates.At(typ).(*postponed)
  if !ok {
  m.JSCreateWithParams(t.Elem(), params)
@@ -202,8 +196,8 @@ func (m *module) PostponedCreates() []string {
  }
 
  switch t := key.(type) {
- case *types.Array:
- result[pp.index] = fmt.Sprintf("%s$Create.Array(%s)", pre, m.JSCreateWithParams(t.Elem(), pp.params))
+ case *types.Array, *types.Slice:
+ result[pp.index] = fmt.Sprintf("%s$Create.Array(%s)", pre, m.JSCreateWithParams(t.(interface{ Elem() types.Type }).Elem(), pp.params))
 
  case *types.Map:
  result[pp.index] = fmt.Sprintf(
@@ -247,9 +241,6 @@ func (m *module) PostponedCreates() []string {
  case *types.Pointer:
  result[pp.index] = fmt.Sprintf("%s$Create.Nullable(%s)", pre, m.JSCreateWithParams(t.Elem(), pp.params))
 
- case *types.Slice:
- result[pp.index] = fmt.Sprintf("%s$Create.Array(%s)", pre, m.JSCreateWithParams(t.Elem(), pp.params))
-
  case *types.Struct:
  info := m.collector.Struct(t)
  info.Collect()

v3/internal/parser/render/default.go

@@ -23,9 +23,8 @@ func (m *module) JSDefault(typ types.Type, quoted bool) (result string) {
  return result
  }
 
- case *types.Array:
- if types.Identical(t.Elem(), types.Universe.Lookup("byte").Type()) {
- // encoding/json marshals byte arrays as base64 strings
+ case *types.Array, *types.Slice:
+ if types.Identical(typ, typeByteSlice) {
  return `""`
  } else {
  return "[]"
@@ -40,14 +39,6 @@ func (m *module) JSDefault(typ types.Type, quoted bool) (result string) {
  case *types.Pointer:
  return "null"
 
- case *types.Slice:
- if types.Identical(t.Elem(), types.Universe.Lookup("byte").Type()) {
- // encoding/json marshals byte slices as base64 strings
- return `""`
- } else {
- return "[]"
- }
-
  case *types.Struct:
  return m.renderStructDefault(t)
  }

v3/internal/parser/render/type.go

@@ -15,6 +15,9 @@ type aliasOrNamed interface {
  Obj() *types.TypeName
 }
 
+// typeByteSlice caches the type-checker type for a slice of bytes.
+var typeByteSlice = types.NewSlice(types.Universe.Lookup("byte").Type())
+
 // JSType renders a Go type to its TypeScript representation,
 // using the receiver's import map to resolve dependencies.
 //
@@ -44,24 +47,22 @@ func (m *module) renderType(typ types.Type, quoted bool) (result string, nullabl
  return m.renderNamedType(typ.(aliasOrNamed), quoted)
 
  case *types.Array, *types.Slice:
- elem := typ.(interface{ Elem() types.Type }).Elem()
-
  null := ""
  if _, isSlice := typ.(*types.Slice); isSlice && m.UseInterfaces {
  // In interface mode, record the fact that encoding/json marshals nil slices as null.
  null = " | null"
  }
 
- if types.Identical(elem, types.Universe.Lookup("byte").Type()) {
+ if types.Identical(typ, typeByteSlice) {
  // encoding/json marshals byte arrays/slices as base64 strings
  return "string" + null, null != ""
  }
 
- elemr, ptr := m.renderType(elem, false)
+ elem, ptr := m.renderType(typ.(interface{ Elem() types.Type }).Elem(), false)
  if ptr {
- return fmt.Sprintf("(%s)[]%s", elemr, null), null != ""
+ return fmt.Sprintf("(%s)[]%s", elem, null), null != ""
  } else {
- return fmt.Sprintf("%s[]%s", elemr, null), null != ""
+ return fmt.Sprintf("%s[]%s", elem, null), null != ""
  }
 
  case *types.Basic:

v3/internal/runtime/desktop/@wailsio/runtime/src/create.js

@@ -20,6 +20,16 @@ export function Any(source) {
  return /** @type {T} */(source);
 }
 
+/**
+ * ByteSlice is a creation function that replaces
+ * null strings with empty strings.
+ * @param {any} source
+ * @returns {string}
+ */
+export function ByteSlice(source) {
+ return /** @type {any} */((source == null) ? "" : source);
+}
+
 /**
  * Array takes a creation function for an arbitrary type
  * and returns an in-place creation function for an array