channeldb/migration12: add tlv invoice migration tests

channeldb/migtest/migtest.go

@@ -0,0 +1,93 @@
+package migtest
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/coreos/bbolt"
+	"github.com/lightningnetwork/lnd/channeldb"
+)
+
+// MakeDB creates a new instance of the ChannelDB for testing purposes. A
+// callback which cleans up the created temporary directories is also returned
+// and intended to be executed after the test completes.
+func MakeDB() (*channeldb.DB, func(), error) {
+	// First, create a temporary directory to be used for the duration of
+	// this test.
+	tempDirName, err := ioutil.TempDir("", "channeldb")
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Next, create channeldb for the first time.
+	cdb, err := channeldb.Open(tempDirName)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	cleanUp := func() {
+		cdb.Close()
+		os.RemoveAll(tempDirName)
+	}
+
+	return cdb, cleanUp, nil
+}
+
+// ApplyMigration is a helper test function that encapsulates the general steps
+// which are needed to properly check the result of applying migration function.
+func ApplyMigration(t *testing.T,
+	beforeMigration, afterMigration, migrationFunc func(tx *bbolt.Tx) error,
+	shouldFail bool) {
+
+	cdb, cleanUp, err := MakeDB()
+	defer cleanUp()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// beforeMigration usually used for populating the database
+	// with test data.
+	err = cdb.Update(beforeMigration)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() {
+		if r := recover(); r != nil {
+			err = newError(r)
+		}
+
+		if err == nil && shouldFail {
+			t.Fatal("error wasn't received on migration stage")
+		} else if err != nil && !shouldFail {
+			t.Fatalf("error was received on migration stage: %v", err)
+		}
+
+		// afterMigration usually used for checking the database state and
+		// throwing the error if something went wrong.
+		err = cdb.Update(afterMigration)
+		if err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// Apply migration.
+	err = cdb.Update(migrationFunc)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func newError(e interface{}) error {
+	var err error
+	switch e := e.(type) {
+	case error:
+		err = e
+	default:
+		err = fmt.Errorf("%v", e)
+	}
+
+	return err
+}