初始提交: Gitea 项目代码

build/openapi3gen/enumscan.go

@@ -0,0 +1,188 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+// Package openapi3gen converts Gitea's Swagger 2.0 spec to an OpenAPI 3.0
+// spec. It discovers Go enum type names by scanning swagger:enum annotations
+// in the source tree, then names extracted shared-enum schemas accordingly.
+package openapi3gen
+
+import (
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"os"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// EnumKey returns a canonical key for a set of enum values: values are
+// stringified, sorted, and joined with "|". Used to match enum value sets
+// across spec properties and scanned Go type declarations.
+func EnumKey(values []any) string {
+	strs := make([]string, len(values))
+	for i, v := range values {
+		strs[i] = fmt.Sprintf("%v", v)
+	}
+	sort.Strings(strs)
+	return strings.Join(strs, "|")
+}
+
+var rxSwaggerEnum = regexp.MustCompile(`swagger:enum\s+(\w+)`)
+
+// ScanSwaggerEnumTypes walks .go files under each dir and returns a map from
+// a canonical value-set key (see EnumKey) to the Go type name declared with
+// // swagger:enum TypeName.
+//
+// Returns an error on parse failure, on an annotation for a type whose
+// constants can't be extracted, or on value-set collisions between two
+// different enum types.
+func ScanSwaggerEnumTypes(dirs []string) (map[string]string, error) {
+	fset := token.NewFileSet()
+	parsed := []*ast.File{}
+
+	for _, dir := range dirs {
+		entries, err := os.ReadDir(dir)
+		if err != nil {
+			return nil, fmt.Errorf("reading %s: %w", dir, err)
+		}
+		for _, entry := range entries {
+			if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".go") {
+				continue
+			}
+			if strings.HasSuffix(entry.Name(), "_test.go") {
+				continue
+			}
+			path := filepath.Join(dir, entry.Name())
+			file, err := parser.ParseFile(fset, path, nil, parser.ParseComments)
+			if err != nil {
+				return nil, fmt.Errorf("%s: %w", path, err)
+			}
+			parsed = append(parsed, file)
+		}
+	}
+
+	enumTypes := map[string]string{} // typeName → "" (presence marker)
+	enumValues := map[string][]any{} // typeName → values
+
+	// Pass 1: collect every // swagger:enum TypeName declaration.
+	for _, file := range parsed {
+		for _, decl := range file.Decls {
+			gd, ok := decl.(*ast.GenDecl)
+			if !ok || gd.Tok != token.TYPE {
+				continue
+			}
+			if err := collectEnumType(gd, enumTypes); err != nil {
+				return nil, fmt.Errorf("%s: %w", fset.Position(gd.Pos()).Filename, err)
+			}
+		}
+	}
+
+	// Pass 2: collect const values; now every annotated type is visible.
+	for _, file := range parsed {
+		for _, decl := range file.Decls {
+			gd, ok := decl.(*ast.GenDecl)
+			if !ok || gd.Tok != token.CONST {
+				continue
+			}
+			collectEnumValues(gd, enumTypes, enumValues)
+		}
+	}
+
+	result := map[string]string{}
+	for typeName := range enumTypes {
+		values, ok := enumValues[typeName]
+		if !ok || len(values) == 0 {
+			return nil, fmt.Errorf("swagger:enum %s has no const block with typed string values", typeName)
+		}
+		key := EnumKey(values)
+		if existing, ok := result[key]; ok && existing != typeName {
+			return nil, fmt.Errorf("swagger:enum value-set collision: %s and %s both use %q", existing, typeName, key)
+		}
+		result[key] = typeName
+	}
+	return result, nil
+}
+
+// collectEnumType scans a `type` GenDecl for // swagger:enum annotations,
+// handling both the lone form (`// swagger:enum Foo\n type Foo string`)
+// where the comment group is attached to the GenDecl, and the grouped form:
+//
+//	type (
+//	    // swagger:enum Foo
+//	    Foo string
+//	)
+//
+// where the comment group is attached to each TypeSpec. Caveat: Go's parser
+// only attaches a CommentGroup when it is immediately adjacent to the decl.
+// A blank line (not a `//` continuation line) between the comment and the
+// declaration drops the Doc, so annotations MUST sit directly above their
+// type. All current annotated files obey this — the rule is noted here so
+// a future edit that inserts a blank line fails fast rather than silently.
+func collectEnumType(gd *ast.GenDecl, enumTypes map[string]string) error {
+	if err := registerEnumAnnotation(gd.Doc, gd.Specs, enumTypes); err != nil {
+		return err
+	}
+	for _, spec := range gd.Specs {
+		ts, ok := spec.(*ast.TypeSpec)
+		if !ok || ts.Doc == nil {
+			continue
+		}
+		if err := registerEnumAnnotation(ts.Doc, []ast.Spec{ts}, enumTypes); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func registerEnumAnnotation(doc *ast.CommentGroup, specs []ast.Spec, enumTypes map[string]string) error {
+	if doc == nil {
+		return nil
+	}
+	matches := rxSwaggerEnum.FindStringSubmatch(doc.Text())
+	if len(matches) < 2 {
+		return nil
+	}
+	annotated := matches[1]
+	for _, spec := range specs {
+		ts, ok := spec.(*ast.TypeSpec)
+		if !ok {
+			continue
+		}
+		if ts.Name.Name == annotated {
+			enumTypes[annotated] = ""
+			return nil
+		}
+	}
+	return fmt.Errorf("swagger:enum %s: no type declaration with that name in the same decl group; check for a typo", annotated)
+}
+
+func collectEnumValues(gd *ast.GenDecl, enumTypes map[string]string, enumValues map[string][]any) {
+	for _, spec := range gd.Specs {
+		vs, ok := spec.(*ast.ValueSpec)
+		if !ok || vs.Type == nil {
+			continue
+		}
+		ident, ok := vs.Type.(*ast.Ident)
+		if !ok {
+			continue
+		}
+		if _, isEnum := enumTypes[ident.Name]; !isEnum {
+			continue
+		}
+		for _, val := range vs.Values {
+			lit, ok := val.(*ast.BasicLit)
+			if !ok || lit.Kind != token.STRING {
+				continue
+			}
+			unquoted, err := strconv.Unquote(lit.Value)
+			if err != nil {
+				continue
+			}
+			enumValues[ident.Name] = append(enumValues[ident.Name], unquoted)
+		}
+	}
+}