refactor: use multierror (#13)

cmd/rpmdb/main.go

@@ -4,24 +4,24 @@ import (
 	"fmt"
 	"log"
 
+	multierror "github.com/hashicorp/go-multierror"
 	rpmdb "github.com/knqyf263/go-rpmdb/pkg"
 )
 
 func main() {
-	db, err := rpmdb.Open("./rpmdb.sqlite")
-	if err != nil {
-		db, err = rpmdb.Open("./Packages.db")
-	}
-	if err != nil {
-		db, err = rpmdb.Open("./Packages")
+	if err := run(); err != nil {
+		log.Fatal(err)
 	}
+}
 
+func run() error {
+	db, err := detectDB()
 	if err != nil {
-		log.Fatal(err)
+		return err
 	}
 	pkgList, err := db.ListPackages()
 	if err != nil {
-		log.Fatal(err)
+		return err
 	}
 
 	fmt.Println("Packages:")
@@ -34,4 +34,29 @@ func main() {
 		fmt.Printf("\t%+v\n", *pkg)
 	}
 	fmt.Printf("[Total Packages: %d]\n", len(pkgList))
+
+	return nil
+}
+
+func detectDB() (*rpmdb.RpmDB, error) {
+	var result error
+	db, err := rpmdb.Open("./rpmdb.sqlite")
+	if err == nil {
+		return db, nil
+	}
+	result = multierror.Append(result, err)
+
+	db, err = rpmdb.Open("./Packages.db")
+	if err == nil {
+		return db, nil
+	}
+	result = multierror.Append(result, err)
+
+	db, err = rpmdb.Open("./Packages")
+	if err == nil {
+		return db, nil
+	}
+	result = multierror.Append(result, err)
+
+	return nil, result
 }

go.mod

@@ -3,6 +3,7 @@ module github.com/knqyf263/go-rpmdb
 go 1.14
 
 require (
+	github.com/hashicorp/go-multierror v1.1.1
 	github.com/stretchr/testify v1.7.0
 	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1
 	modernc.org/sqlite v1.14.5

go.sum

@@ -6,6 +6,10 @@ github.com/google/go-cmp v0.5.3 h1:x95R7cp+rSeeqAMI2knLtQ0DKlaBhv2NrtrOvafPHRo=
 github.com/google/go-cmp v0.5.3/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/hashicorp/errwrap v1.0.0 h1:hLrqtEDnRye3+sgx6z4qVLNuviH3MR5aQ0ykNJa/UYA=
+github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
+github.com/hashicorp/go-multierror v1.1.1 h1:H5DkEtf6CXdFp0N0Em5UCwQpXMWke8IA0+lD48awMYo=
+github.com/hashicorp/go-multierror v1.1.1/go.mod h1:iw975J/qwKPdAO1clOe2L8331t/9/fmwbPZ6JB6eMoM=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 h1:Z9n2FFNUXsshfwJMBgNA0RU6/i7WVaAegv3PtuIHPMs=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:CzGEWj7cYgsdH8dAjBGEr58BoE7ScuLd+fwFZ44+/x8=
 github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=