Add test for to prevent double create

backend/local/backend_test.go

@@ -7,13 +7,14 @@ import (
 	"github.com/restic/restic/backend/test"
 )
 
-func TestLocalBackendCreate(t *testing.T)    { test.Create(t) }
+func TestLocalBackendCreate(t *testing.T)           { test.Create(t) }
-func TestLocalBackendOpen(t *testing.T)      { test.Open(t) }
+func TestLocalBackendOpen(t *testing.T)             { test.Open(t) }
-func TestLocalBackendLocation(t *testing.T)  { test.Location(t) }
+func TestLocalBackendCreateWithConfig(t *testing.T) { test.CreateWithConfig(t) }
-func TestLocalBackendConfig(t *testing.T)    { test.Config(t) }
+func TestLocalBackendLocation(t *testing.T)         { test.Location(t) }
-func TestLocalBackendGetReader(t *testing.T) { test.GetReader(t) }
+func TestLocalBackendConfig(t *testing.T)           { test.Config(t) }
-func TestLocalBackendLoad(t *testing.T)      { test.Load(t) }
+func TestLocalBackendGetReader(t *testing.T)        { test.GetReader(t) }
-func TestLocalBackendWrite(t *testing.T)     { test.Write(t) }
+func TestLocalBackendLoad(t *testing.T)             { test.Load(t) }
-func TestLocalBackendGeneric(t *testing.T)   { test.Generic(t) }
+func TestLocalBackendWrite(t *testing.T)            { test.Write(t) }
-func TestLocalBackendDelete(t *testing.T)    { test.Delete(t) }
+func TestLocalBackendGeneric(t *testing.T)          { test.Generic(t) }
-func TestLocalBackendCleanup(t *testing.T)   { test.Cleanup(t) }
+func TestLocalBackendDelete(t *testing.T)           { test.Delete(t) }
+func TestLocalBackendCleanup(t *testing.T)          { test.Cleanup(t) }

backend/local/local_test.go

@@ -1,7 +1,6 @@
 package local_test
 
 import (
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -15,28 +14,35 @@ var tempBackendDir string
 
 //go:generate go run ../test/generate_backend_tests.go
 
+func createTempdir() error {
+	if tempBackendDir != "" {
+		return nil
+	}
+
+	tempdir, err := ioutil.TempDir("", "restic-local-test-")
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("created new test backend at %v\n", tempdir)
+	tempBackendDir = tempdir
+	return nil
+}
+
 func init() {
 	test.CreateFn = func() (backend.Backend, error) {
-		if tempBackendDir != "" {
+		err := createTempdir()
-			return nil, errors.New("temporary local backend dir already exists")
-		}
-
-		tempdir, err := ioutil.TempDir("", "restic-local-test-")
 		if err != nil {
 			return nil, err
 		}
-
+		return local.Create(tempBackendDir)
-		fmt.Printf("created new test backend at %v\n", tempdir)
-		tempBackendDir = tempdir
-
-		return local.Create(tempdir)
 	}
 
 	test.OpenFn = func() (backend.Backend, error) {
-		if tempBackendDir == "" {
+		err := createTempdir()
-			return nil, errors.New("repository not initialized")
+		if err != nil {
+			return nil, err
 		}
-
 		return local.Open(tempBackendDir)
 	}
 

backend/mem_backend_test.go

@@ -7,13 +7,14 @@ import (
 	"github.com/restic/restic/backend/test"
 )
 
-func TestMemBackendCreate(t *testing.T)    { test.Create(t) }
+func TestMemBackendCreate(t *testing.T)           { test.Create(t) }
-func TestMemBackendOpen(t *testing.T)      { test.Open(t) }
+func TestMemBackendOpen(t *testing.T)             { test.Open(t) }
-func TestMemBackendLocation(t *testing.T)  { test.Location(t) }
+func TestMemBackendCreateWithConfig(t *testing.T) { test.CreateWithConfig(t) }
-func TestMemBackendConfig(t *testing.T)    { test.Config(t) }
+func TestMemBackendLocation(t *testing.T)         { test.Location(t) }
-func TestMemBackendGetReader(t *testing.T) { test.GetReader(t) }
+func TestMemBackendConfig(t *testing.T)           { test.Config(t) }
-func TestMemBackendLoad(t *testing.T)      { test.Load(t) }
+func TestMemBackendGetReader(t *testing.T)        { test.GetReader(t) }
-func TestMemBackendWrite(t *testing.T)     { test.Write(t) }
+func TestMemBackendLoad(t *testing.T)             { test.Load(t) }
-func TestMemBackendGeneric(t *testing.T)   { test.Generic(t) }
+func TestMemBackendWrite(t *testing.T)            { test.Write(t) }
-func TestMemBackendDelete(t *testing.T)    { test.Delete(t) }
+func TestMemBackendGeneric(t *testing.T)          { test.Generic(t) }
-func TestMemBackendCleanup(t *testing.T)   { test.Cleanup(t) }
+func TestMemBackendDelete(t *testing.T)           { test.Delete(t) }
+func TestMemBackendCleanup(t *testing.T)          { test.Cleanup(t) }

backend/test/backend_test.go

@@ -7,13 +7,14 @@ import (
 	"github.com/restic/restic/backend/test"
 )
 
-func TestTestBackendCreate(t *testing.T)    { test.Create(t) }
+func TestTestBackendCreate(t *testing.T)           { test.Create(t) }
-func TestTestBackendOpen(t *testing.T)      { test.Open(t) }
+func TestTestBackendOpen(t *testing.T)             { test.Open(t) }
-func TestTestBackendLocation(t *testing.T)  { test.Location(t) }
+func TestTestBackendCreateWithConfig(t *testing.T) { test.CreateWithConfig(t) }
-func TestTestBackendConfig(t *testing.T)    { test.Config(t) }
+func TestTestBackendLocation(t *testing.T)         { test.Location(t) }
-func TestTestBackendGetReader(t *testing.T) { test.GetReader(t) }
+func TestTestBackendConfig(t *testing.T)           { test.Config(t) }
-func TestTestBackendLoad(t *testing.T)      { test.Load(t) }
+func TestTestBackendGetReader(t *testing.T)        { test.GetReader(t) }
-func TestTestBackendWrite(t *testing.T)     { test.Write(t) }
+func TestTestBackendLoad(t *testing.T)             { test.Load(t) }
-func TestTestBackendGeneric(t *testing.T)   { test.Generic(t) }
+func TestTestBackendWrite(t *testing.T)            { test.Write(t) }
-func TestTestBackendDelete(t *testing.T)    { test.Delete(t) }
+func TestTestBackendGeneric(t *testing.T)          { test.Generic(t) }
-func TestTestBackendCleanup(t *testing.T)   { test.Cleanup(t) }
+func TestTestBackendDelete(t *testing.T)           { test.Delete(t) }
+func TestTestBackendCleanup(t *testing.T)          { test.Cleanup(t) }

backend/test/tests.go

@@ -107,6 +107,32 @@ func Open(t testing.TB) {
 	}
 }
 
+// CreateWithConfig tests that creating a backend in a location which already
+// has a config file fails.
+func CreateWithConfig(t testing.TB) {
+	if CreateFn == nil {
+		t.Fatalf("CreateFn not set")
+	}
+
+	b := open(t)
+	defer close(t)
+
+	// save a config
+	store(t, b, backend.Config, []byte("test config"))
+
+	// now create the backend again, this must fail
+	_, err := CreateFn()
+	if err == nil {
+		t.Fatalf("expected error not found for creating a backend with an existing config file")
+	}
+
+	// remove config
+	err = b.Remove(backend.Config, "")
+	if err != nil {
+		t.Fatalf("unexpected error removing config: %v", err)
+	}
+}
+
 // Location tests that a location string is returned.
 func Location(t testing.TB) {
 	b := open(t)