added context test, JSON export/import

go/base/context.go

@@ -8,6 +8,7 @@ package base
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"os"
 	"regexp"
 	"strings"
@@ -256,8 +257,12 @@ func (this *MigrationContext) LoadJSON(jsonString string) error {
 	defer this.throttleMutex.Unlock()
 
 	jsonBytes := []byte(jsonString)
-	err := json.Unmarshal(jsonBytes, this)
 
+	if err := json.Unmarshal(jsonBytes, this); err != nil && err != io.EOF {
+		return err
+	}
+
+	var err error
 	if this.MigrationRangeMinValues, err = sql.NewColumnValuesFromBase64(this.EncodedRangeValues["MigrationRangeMinValues"]); err != nil {
 		return err
 	}
@@ -271,7 +276,7 @@ func (this *MigrationContext) LoadJSON(jsonString string) error {
 		return err
 	}
 
-	return err
+	return nil
 }
 
 // GetGhostTableName generates the name of ghost table, based on original table name

go/base/context_test.go

@@ -0,0 +1,54 @@
+/*
+   Copyright 2016 GitHub Inc.
+	 See https://github.com/github/gh-ost/blob/master/LICENSE
+*/
+
+package base
+
+import (
+	"io"
+	"testing"
+
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
+
+	"github.com/github/gh-ost/go/mysql"
+	"github.com/github/gh-ost/go/sql"
+)
+
+func init() {
+	log.SetLevel(log.ERROR)
+}
+
+func TestContextToJSON(t *testing.T) {
+	context := NewMigrationContext()
+	jsonString, err := context.ToJSON()
+	test.S(t).ExpectNil(err)
+	test.S(t).ExpectNotEquals(jsonString, "")
+}
+
+func TestContextLoadJSON(t *testing.T) {
+	var jsonString string
+	var err error
+	{
+		context := NewMigrationContext()
+		context.AppliedBinlogCoordinates = mysql.BinlogCoordinates{LogFile: "mysql-bin.012345", LogPos: 6789}
+
+		abstractValues := []interface{}{31, "2016-12-24 17:04:32"}
+		context.MigrationRangeMinValues = sql.ToColumnValues(abstractValues)
+
+		jsonString, err = context.ToJSON()
+		test.S(t).ExpectNil(err)
+		test.S(t).ExpectNotEquals(jsonString, "")
+	}
+	{
+		context := NewMigrationContext()
+		err = context.LoadJSON(jsonString)
+		test.S(t).ExpectEqualsAny(err, nil, io.EOF)
+		test.S(t).ExpectEquals(context.AppliedBinlogCoordinates, mysql.BinlogCoordinates{LogFile: "mysql-bin.012345", LogPos: 6789})
+		abstractValues := context.MigrationRangeMinValues.AbstractValues()
+		test.S(t).ExpectEquals(len(abstractValues), 2)
+		test.S(t).ExpectEquals(abstractValues[0], 31)
+		test.S(t).ExpectEquals(abstractValues[1], "2016-12-24 17:04:32")
+	}
+}