refactor(strcase,BREAKING!): adopt STYLE2024 case conversion rules

internal/confgen/document_parser.go

@@ -5,7 +5,6 @@ import (
 	"strings"
 
 	"github.com/tableauio/tableau/internal/importer/book"
-	"github.com/tableauio/tableau/internal/strcase"
 	"github.com/tableauio/tableau/internal/types"
 	"github.com/tableauio/tableau/internal/x/xerrors"
 	"github.com/tableauio/tableau/internal/x/xproto"
@@ -438,7 +437,7 @@ func (p *documentParser) parseUnionMessage(field *Field, msg protoreflect.Messag
 	}
 
 	// parse union type
-	typeNodeName := strcase.FromContext(p.ctx).ToCamel(unionDesc.TypeName())
+	typeNodeName := unionDesc.TypeName()
 	typeNode := node.FindChild(typeNodeName)
 	if typeNode == nil && xproto.GetFieldDefaultValue(unionDesc.Type) != "" {
 		// if this field has a default value, use virtual node

internal/confgen/table_parser.go

@@ -7,7 +7,6 @@ import (
 	"github.com/tableauio/tableau/internal/confgen/fieldprop"
 	"github.com/tableauio/tableau/internal/importer/book"
 	"github.com/tableauio/tableau/internal/importer/book/tableparser"
-	"github.com/tableauio/tableau/internal/strcase"
 	"github.com/tableauio/tableau/internal/types"
 	"github.com/tableauio/tableau/internal/x/xerrors"
 	"github.com/tableauio/tableau/internal/x/xproto"
@@ -756,7 +755,7 @@ func (p *tableParser) parseUnionMessage(msg protoreflect.Message, field *Field,
 	}
 
 	// parse union type
-	typeColName := prefix + strcase.FromContext(p.ctx).ToCamel(unionDesc.TypeName())
+	typeColName := prefix + unionDesc.TypeName()
 	cell, err := r.Cell(typeColName, p.IsFieldOptional(field))
 	if err != nil {
 		return false, err

internal/protogen/exporter.go

@@ -26,7 +26,7 @@ import (
 
 type bookExporter struct {
 	ProtoPackage     string
-	Edition          string
+	Edition          int
 	ProtoFileOptions map[string]string
 	OutputDir        string
 	FilenameSuffix   string
@@ -37,7 +37,7 @@ type bookExporter struct {
 	messagerPatternRegexp *regexp.Regexp
 }
 
-func newBookExporter(protoPackage string, edition string, protoFileOptions map[string]string, outputDir, filenameSuffix string, wb *internalpb.Workbook, gen *Generator) *bookExporter {
+func newBookExporter(protoPackage string, edition int, protoFileOptions map[string]string, outputDir, filenameSuffix string, wb *internalpb.Workbook, gen *Generator) *bookExporter {
 	return &bookExporter{
 		ProtoPackage:          protoPackage,
 		Edition:               edition,
@@ -60,7 +60,7 @@ func (x *bookExporter) export(checkProtoFileConflicts bool) error {
 	p1.P("// Code generated by tableau (protogen v", Version, "). DO NOT EDIT.")
 	p1.P("// clang-format off")
 	p1.P("")
-	if x.Edition != "" {
+	if x.Edition != 0 {
 		p1.P(`edition = "`, x.Edition, `";`)
 	} else {
 		p1.P(`syntax = "proto3";`)
@@ -301,18 +301,17 @@ func (x *sheetExporter) exportUnion() error {
 		if field.Number == 0 {
 			continue
 		}
-		ename := "TYPE_" + strcase.FromContext(x.be.gen.ctx).ToScreamingSnake(field.Name)
-		typ := field.Name
-		fullTypeName := field.FullType
-		if fullTypeName != "" {
-			typ = fullTypeName
+		ename := strcase.FromContext(x.be.gen.ctx).EnumValue("Type", field.Name)
+		typ := field.FullType
+		if typ == "" {
+			typ = strcase.FromContext(x.be.gen.ctx).ToCamel(field.Name)
 		}
 		// Add import for predefined types (e.g. protoconf.FruitType, protoconf.Item).
 		if field.Predefined {
-			if types.IsWellKnownMessage(fullTypeName) {
-				importPath := types.GetWellKnownMessageImport(fullTypeName)
+			if types.IsWellKnownMessage(typ) {
+				importPath := types.GetWellKnownMessageImport(typ)
 				x.Imports[importPath] = true
-			} else if typeInfo := x.typeInfos.GetByFullName(protoreflect.FullName(fullTypeName)); typeInfo != nil &&
+			} else if typeInfo := x.typeInfos.GetByFullName(protoreflect.FullName(typ)); typeInfo != nil &&
 				typeInfo.ParentFilename != x.be.GetProtoFilePath() {
 				x.Imports[typeInfo.ParentFilename] = true
 			}
@@ -333,7 +332,7 @@ func (x *sheetExporter) exportUnion() error {
 		x.p.P("    TYPE_INVALID = 0;")
 	}
 	for _, field := range x.ws.Fields {
-		ename := "TYPE_" + strcase.FromContext(x.be.gen.ctx).ToScreamingSnake(field.Name)
+		ename := strcase.FromContext(x.be.gen.ctx).EnumValue("Type", field.Name)
 		note := ""
 		if field.Alias != "" {
 			note = " // " + field.Alias
@@ -349,9 +348,9 @@ func (x *sheetExporter) exportUnion() error {
 		if len(msgField.Fields) == 0 {
 			continue
 		}
-		typ := msgField.Name
-		if msgField.Type != "" {
-			typ = msgField.Type
+		typ := msgField.Type
+		if typ == "" {
+			typ = strcase.FromContext(x.be.gen.ctx).ToCamel(msgField.Name)
 		}
 		x.p.P("  message ", typ, " {")
 		// generate the fields

internal/protogen/exporter_test.go

@@ -291,7 +291,7 @@ func Test_bookExporter_GetProtoFilePath(t *testing.T) {
 func Test_bookExporter_export(t *testing.T) {
 	tests := []struct {
 		name             string
-		edition          string
+		edition          int
 		protoFileOptions map[string]string
 		wantContains     []string
 		wantNotContains  []string
@@ -311,7 +311,7 @@ func Test_bookExporter_export(t *testing.T) {
 		},
 		{
 			name:    "edition-2023-with-features-utf8-validation",
-			edition: "2023",
+			edition: 2023,
 			protoFileOptions: map[string]string{
 				"go_package":               `"github.com/example/protoconf"`,
 				"features.utf8_validation": "NONE",
@@ -327,7 +327,7 @@ func Test_bookExporter_export(t *testing.T) {
 		},
 		{
 			name:    "edition-2024-with-features-strip-enum-prefix",
-			edition: "2024",
+			edition: 2024,
 			protoFileOptions: map[string]string{
 				"go_package":                         `"github.com/example/protoconf"`,
 				"features.(pb.go).strip_enum_prefix": "STRIP_ENUM_PREFIX_STRIP",
@@ -348,7 +348,7 @@ func Test_bookExporter_export(t *testing.T) {
 		},
 		{
 			name:    "edition-2024-with-pb-cpp-features-infer-cpp-features-import",
-			edition: "2024",
+			edition: 2024,
 			protoFileOptions: map[string]string{
 				"go_package":                    `"github.com/example/protoconf"`,
 				"features.(pb.cpp).string_type": "VIEW",
@@ -365,7 +365,7 @@ func Test_bookExporter_export(t *testing.T) {
 		},
 		{
 			name:    "edition-2024-with-pb-java-features-infer-java-features-import",
-			edition: "2024",
+			edition: 2024,
 			protoFileOptions: map[string]string{
 				"go_package":                         `"github.com/example/protoconf"`,
 				"features.(pb.java).utf8_validation": "VERIFY",
@@ -382,7 +382,7 @@ func Test_bookExporter_export(t *testing.T) {
 		},
 		{
 			name:    "edition-2024-with-all-language-features-infer-all-imports",
-			edition: "2024",
+			edition: 2024,
 			protoFileOptions: map[string]string{
 				"go_package":                            `"github.com/example/protoconf"`,
 				"features.(pb.go).api_level":            "API_OPAQUE",

internal/protogen/protogen.go

@@ -65,7 +65,17 @@ func NewGenerator(protoPackage, indir, outdir string, setters ...options.Option)
 
 func NewGeneratorWithOptions(protoPackage, indir, outdir string, opts *options.Options) *Generator {
 	ctx := context.Background()
-	ctx = strcase.NewContext(ctx, strcase.New(opts.Acronyms))
+	// STYLE2024 naming is the default. Users can opt back into the legacy
+	// pre-STYLE2024 algorithm via ProtoInputOption.UseLegacyNamingStyle,
+	// EXCEPT when the requested edition itself mandates STYLE2024
+	// (>= EditionStyle2024); in that case the legacy flag is ignored.
+	useLegacy := opts.Proto.Input.UseLegacyNamingStyle &&
+		opts.Proto.Output.Edition < options.EditionStyle2024
+	if useLegacy {
+		ctx = strcase.NewContext(ctx, strcase.NewLegacy(opts.Acronyms))
+	} else {
+		ctx = strcase.NewContext(ctx, strcase.New(opts.Acronyms))
+	}
 	ctx = metasheet.NewContext(ctx, &metasheet.Metasheet{Name: opts.Proto.Input.MetasheetName})
 
 	gen := &Generator{

internal/protogen/sheet_mode.go

@@ -62,15 +62,23 @@ func parseEnumType(ws *internalpb.Worksheet, sheet *book.Sheet, parser book.Shee
 	if err := parser.Parse(desc, sheet); err != nil {
 		return err
 	}
-	prefix := strcase.FromContext(gen.ctx).ToScreamingSnake(ws.Name) + "_"
+	sc := strcase.FromContext(gen.ctx)
 	for i, value := range desc.Values {
 		number := int32(i + 1)
 		if value.Number != nil {
 			number = value.GetNumber()
 		}
-		name := value.Name
-		if gen.OutputOpt.EnumValueWithPrefix && !strings.HasPrefix(name, prefix) {
-			name = prefix + name
+		var name string
+		if sc.Legacy() {
+			// Legacy: the prefix is opt-in via EnumValueWithPrefix, matching
+			// the pre-STYLE2024 generator behavior.
+			name = value.Name
+			if gen.OutputOpt.EnumValueWithPrefix {
+				name = sc.EnumValue(ws.Name, value.Name)
+			}
+		} else {
+			// STYLE2024: the prefix is mandatory.
+			name = sc.EnumValue(ws.Name, value.Name)
 		}
 		field := &internalpb.Field{
 			Number: number,

internal/strcase/README.md

@@ -1,36 +1,63 @@
-# strcase
-
-> NOTE: we learned a lot from package [strcase](https://github.com/iancoleman/strcase)
-
-strcase is a go package for converting string case to various cases (e.g. [snake case](https://en.wikipedia.org/wiki/Snake_case) or [camel case](https://en.wikipedia.org/wiki/CamelCase)) to see the full conversion table below.
-
-## Example
-
-```go
-s := "AnyKind of_string"
-```
-
-| Function                                  | Result               |
-| ----------------------------------------- | -------------------- |
-| `ToSnake(s)`                              | `any_kind_of_string` |
-| `ToSnakeWithIgnore(s, '.')`               | `any_kind.of_string` |
-| `ToScreamingSnake(s)`                     | `ANY_KIND_OF_STRING` |
-| `ToKebab(s)`                              | `any-kind-of-string` |
-| `ToScreamingKebab(s)`                     | `ANY-KIND-OF-STRING` |
-| `ToDelimited(s, '.')`                     | `any.kind.of.string` |
-| `ToScreamingDelimited(s, '.', '', true)`  | `ANY.KIND.OF.STRING` |
-| `ToScreamingDelimited(s, '.', ' ', true)` | `ANY.KIND OF.STRING` |
-| `ToCamel(s)`                              | `AnyKindOfString`    |
-| `ToLowerCamel(s)`                         | `anyKindOfString`    |
-
-## Custom Acronyms
-
-Sometimes, text may contain specific acronyms which need to be handled in a certain way.
-
-```go
-// For "WebAPIV3Spec":
-//  - ToCamel: WebApiv3Spec
-//  - ToLowerCamel: webApiv3Spec
-//  - ToSnake: web_apiv3_spec
-strcase.New(map[string]string{"APIV3": "apiv3"})
-```
+# strcase
+
+> NOTE: we learned a lot from package [strcase](https://github.com/iancoleman/strcase)
+
+strcase is a go package for converting string case to various cases (e.g. [snake case](https://en.wikipedia.org/wiki/Snake_case) or [PascalCase](https://en.wikipedia.org/wiki/Camel_case)) under [STYLE2024](https://protobuf.dev/programming-guides/style/) rules.
+
+## Example
+
+```go
+s := "AnyKind of_string"
+```
+
+| Function              | Result               |
+| --------------------- | -------------------- |
+| `ToCamel(s)`          | `AnyKindOfString`    |
+| `ToLowerCamel(s)`     | `anyKindOfString`    |
+| `ToSnake(s)`          | `any_kind_of_string` |
+| `ToScreamingSnake(s)` | `ANY_KIND_OF_STRING` |
+
+## STYLE2024 highlights
+
+- An underscore is only allowed in front of a letter; therefore no
+  underscore is inserted at letter <-> digit boundaries
+  (e.g. `Tier1` -> `tier1`, NOT `tier_1`).
+- Acronyms are treated as ordinary words
+  (e.g. `JSONData` -> `json_data`, `userID` -> `user_id`).
+
+## Custom Acronyms
+
+Sometimes, text may contain specific acronyms which need to be handled in a certain way.
+
+```go
+// For "WebAPIV3Spec":
+//  - ToCamel: WebApiv3Spec
+//  - ToSnake: web_apiv3_spec
+strcase.New(map[string]string{"APIV3": "apiv3"})
+```
+
+## Legacy (pre-STYLE2024) Mode
+
+Existing projects whose generated proto files were produced under the old
+algorithm can opt back into it by constructing the engine with `NewLegacy`
+instead of `New`. At the public tableau API level this is exposed as
+`useLegacyNamingStyle: true` under the `proto.input` section of the user
+`config.yaml`.
+
+The flag is honored ONLY by protogen — confgen always parses input under
+STYLE2024 rules. It is also force-disabled when the requested edition is
+>= 2024 (`proto.output.edition: 2024`), because edition 2024 itself
+mandates the STYLE2024 naming rules.
+
+Behavioral differences vs STYLE2024:
+
+- Underscores ARE inserted at letter <-> digit boundaries
+  (e.g. `Tier1` -> `tier_1`, `DeviceTier`/`1` -> `DEVICE_TIER_1`).
+- `EnumValue` does NOT inject a leading `V` for digit-led suffixes.
+  `ProtoOutputOption.EnumValueWithPrefix` continues to gate prefixing at the
+  call site under legacy mode.
+- Consecutive uppercase letters are folded to lower in camel form
+  (e.g. `HeroNTagMFcX` -> `HeroNtagMfcX`).
+
+See the strcase tests for an exhaustive, side-by-side enumeration of every
+divergence.