fix: improve Go version detection inside workspace

Author: ldez

pkg/config/config.go

@@ -1,11 +1,16 @@
 package config
 
 import (
+	"cmp"
+	"fmt"
 	"os"
+	"path/filepath"
+	"slices"
 	"strings"
 
 	hcversion "github.com/hashicorp/go-version"
-	"github.com/ldez/gomoddirectives"
+	"github.com/ldez/grignotin/gomod"
+	"golang.org/x/mod/modfile"
 )
 
 // Config encapsulates the config data specified in the golangci-lint YAML config file.
@@ -93,8 +98,33 @@ func detectGoVersion() string {
 // else it returns `go` version if present,
 // else it returns empty.
 func detectGoVersionFromGoMod() string {
-	file, _ := gomoddirectives.GetModuleFile()
-	if file == nil {
+	info, err := gomod.GetModuleInfo()
+	if err != nil {
+		return ""
+	}
+
+	wd, err := os.Getwd()
+	if err != nil {
+		return ""
+	}
+
+	slices.SortFunc(info, func(a, b gomod.ModInfo) int {
+		return cmp.Compare(len(b.Path), len(a.Path))
+	})
+
+	goMod := info[0]
+	for _, m := range info {
+		if !strings.HasPrefix(wd, m.Dir) {
+			continue
+		}
+
+		goMod = m
+
+		break
+	}
+
+	file, err := parseGoMod(goMod.GoMod)
+	if err != nil {
 		return ""
 	}
 
@@ -110,3 +140,12 @@ func detectGoVersionFromGoMod() string {
 
 	return ""
 }
+
+func parseGoMod(goMod string) (*modfile.File, error) {
+	raw, err := os.ReadFile(filepath.Clean(goMod))
+	if err != nil {
+		return nil, fmt.Errorf("reading go.mod file: %w", err)
+	}
+
+	return modfile.Parse("go.mod", raw, nil)
+}