sorted_consts.go

package main

import (
	"bytes"
	"flag"
	"fmt"
	"go/ast"
	"go/parser"
	"go/token"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"sort"
	"strings"
)

var (
	root = flag.String("root", "", "Go source files root dir")
)

func inspectSource(path string, kind ast.ObjKind) bool {
	source, err := ioutil.ReadFile(path)
	if err != nil {
		log.Fatalf("Failed to read %q: %v.", path, err)
	}
	lines := bytes.Split(source, []byte("\n"))
	inIotaGroup := make(map[int]struct{})
	inside := false
	for l, line := range lines {
		if bytes.Contains(line, []byte("iota")) {
			inside = true
		}
		if bytes.Equal(line, []byte(")")) {
			inside = false
		}
		if inside {
			inIotaGroup[l+1] = struct{}{}
		}
	}
	fset := token.NewFileSet()
	f, err := parser.ParseFile(fset, path, source, 0)
	if err != nil {
		log.Fatalf("Failed to parse %q: %v.", path, err)
	}
	var objects []*ast.Object
	for _, obj := range f.Scope.Objects {
		if obj.Kind == kind {
			objects = append(objects, obj)
		}
	}
	sort.Slice(objects, func(i, j int) bool {
		return objects[i].Pos() < objects[j].Pos()
	})
	ok := true
	for i, c := range objects {
		if i == 0 {
			continue
		}
		b := objects[i-1]
		if strings.ToLower(b.Name) <= strings.ToLower(c.Name) {
			continue
		}
		bLine := fset.Position(b.Pos()).Line
		cLine := fset.Position(c.Pos()).Line
		// Skip reporting if they belong to different groups.
		differentGroups := false
		for l := bLine - 1; l < cLine-1; l++ {
			if bytes.Equal(lines[l], []byte(")")) {
				differentGroups = true
			}
		}
		if _, has := inIotaGroup[bLine]; has || differentGroups {
			continue
		}
		fmt.Printf("%s: %s (line %d) and %s (line %d) are not ordered.\n", path, b.Name, bLine, c.Name, cLine)
		ok = false
	}
	return ok
}

func main() {
	flag.Parse()
	if *root == "" {
		log.Fatal("Specify -root")
	}
	ok := true
	filepath.Walk(*root, func(path string, info os.FileInfo, err error) error {
		if err == nil && !info.IsDir() && strings.HasSuffix(path, ".go") && !strings.HasSuffix(path, "_test.go") && !strings.Contains(path, "vendor/") {
			if !inspectSource(path, ast.Con) || !inspectSource(path, ast.Var) {
				ok = false
			}
		}
		return nil
	})
	if !ok {
		os.Exit(1)
	}
}