extract go version without depending on go list

go.mod

@@ -13,6 +13,7 @@ require (
  github.com/olekukonko/tablewriter v0.0.5
  github.com/pkg/errors v0.9.1
  github.com/spf13/afero v1.11.0
+ golang.org/x/mod v0.20.0
  golang.org/x/tools v0.24.0
 )
 

go.sum

@@ -38,16 +38,14 @@ github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/mod v0.20.0 h1:utOm6MM3R3dnawAiJgn0y+xvuYRsm1RKM/4giyfDgV0=
+golang.org/x/mod v0.20.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
-golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.23.0 h1:YfKFowiIMvtgl1UERQoTPPToxltDeZfbj4H7dVUCwmM=
 golang.org/x/sys v0.23.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
-golang.org/x/tools v0.23.0 h1:SGsXPZ+2l4JsgaCKkx+FQ9YZ5XEtA1GZYuoDjenLjvg=
-golang.org/x/tools v0.23.0/go.mod h1:pnu6ufv6vQkll6szChhK3C3L/ruaIv5eBeztNG8wtsI=
 golang.org/x/tools v0.24.0 h1:J1shsA93PJUEVaUSaay7UXAyE8aimq3GW0pjlolpa24=
 golang.org/x/tools v0.24.0/go.mod h1:YhNqVBIfWHdzvTLs0d8LCuMhkKUgSUKldakyV7W/WDQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

lint/linter.go

@@ -3,18 +3,18 @@ package lint
 import (
  "bufio"
  "bytes"
- "encoding/json"
  "fmt"
  "go/token"
  "os"
- "os/exec"
+ "path"
  "path/filepath"
  "regexp"
  "strconv"
  "strings"
  "sync"
 
  goversion "github.com/hashicorp/go-version"
+ "golang.org/x/mod/modfile"
 )
 
 // ReadFile defines an abstraction for reading files.
@@ -156,37 +156,42 @@ func (l *Linter) lintPackage(filenames []string, gover *goversion.Version, ruleS
 }
 
 func detectGoMod(dir string) (rootDir string, ver *goversion.Version, err error) {
- // https://github.com/golang/go/issues/44753#issuecomment-790089020
- cmd := exec.Command("go", "list", "-m", "-json")
- cmd.Dir = dir
+ modFileName, err := retrieveModFile(dir)
+ if err != nil {
+ return "", nil, fmt.Errorf("%q doesn't seem to be part of a Go module", dir)
+ }
 
- out, err := cmd.Output()
+ mod, err := os.ReadFile(modFileName)
  if err != nil {
- return "", nil, fmt.Errorf("command go list: %w", err)
+ return "", nil, fmt.Errorf("failed to read %q, got %v", modFileName, err)
  }
 
- // NOTE: A package may be part of a go workspace. In this case `go list -m`
- // lists all modules in the workspace, so we need to go through them all.
- d := json.NewDecoder(bytes.NewBuffer(out))
- for d.More() {
- var v struct {
-  GoMod string `json:"GoMod"`
-  GoVersion string `json:"GoVersion"`
- Dir string `json:"Dir"`
- }
- if err = d.Decode(&v); err != nil {
-  return "", nil, err
-  }
- if v.GoMod == "" {
- return "", nil, fmt.Errorf("not part of a module: %q", dir)
+ modAst, err := modfile.ParseLax(modFileName, mod, nil)
+ if err != nil {
+  return "", nil, fmt.Errorf("failed to parse %q, got %v", modFileName, err)
+ }
+
+ ver, err = goversion.NewVersion(modAst.Go.Version)
+ return path.Dir(modFileName), ver, err
+}
+
+func retrieveModFile(dir string) (string, error) {
+ const lookingForFile = "go.mod"
+ for {
+ if dir == "." || dir == "/" {
+ return "", fmt.Errorf("did not found %q file", lookingForFile)
  }
- if v.Dir != "" && strings.HasPrefix(dir, v.Dir) {
- rootDir = v.Dir
- ver, err = goversion.NewVersion(strings.TrimPrefix(v.GoVersion, "go"))
- return rootDir, ver, err
+
+ lookingForFilePath := path.Join(dir, lookingForFile)
+ info, err := os.Stat(lookingForFilePath)
+ if err != nil || info.IsDir() {
+ // lets check the parent dir
+ dir = path.Dir(dir)
+ continue
  }
+
+ return lookingForFilePath, nil
  }
- return "", nil, fmt.Errorf("not part of a module: %q", dir)
 }
 
 // isGenerated reports whether the source file is generated code