diff --git a/common/net/transport.go b/common/net/transport.go
index 20741bde..a4b66797 100644
--- a/common/net/transport.go
+++ b/common/net/transport.go
@@ -19,7 +19,6 @@ func ReaderToChan(stream chan<- []byte, reader io.Reader) error {
 			return err
 		}
 	}
-	return nil
 }
 
 func ChanToWriter(writer io.Writer, stream <-chan []byte) error {
diff --git a/config/json/json.go b/config/json/json.go
index 76ff0d0d..5a8f3cbf 100644
--- a/config/json/json.go
+++ b/config/json/json.go
@@ -3,6 +3,7 @@ package json
 import (
 	"encoding/json"
 	"io/ioutil"
+	"os"
 	"path/filepath"
 
 	"github.com/v2ray/v2ray-core"
@@ -49,7 +50,8 @@ func (config *Config) OutboundConfig() core.ConnectionConfig {
 }
 
 func LoadConfig(file string) (*Config, error) {
-	rawConfig, err := ioutil.ReadFile(file)
+	fixedFile := os.ExpandEnv(file)
+	rawConfig, err := ioutil.ReadFile(fixedFile)
 	if err != nil {
 		log.Error("Failed to read point config file (%s): %v", file, err)
 		return nil, err
@@ -59,11 +61,11 @@ func LoadConfig(file string) (*Config, error) {
 	err = json.Unmarshal(rawConfig, config)
 
 	if !filepath.IsAbs(config.InboundConfigValue.File) && len(config.InboundConfigValue.File) > 0 {
-		config.InboundConfigValue.File = filepath.Join(filepath.Dir(file), config.InboundConfigValue.File)
+		config.InboundConfigValue.File = filepath.Join(filepath.Dir(fixedFile), config.InboundConfigValue.File)
 	}
 
 	if !filepath.IsAbs(config.OutboundConfigValue.File) && len(config.OutboundConfigValue.File) > 0 {
-		config.OutboundConfigValue.File = filepath.Join(filepath.Dir(file), config.OutboundConfigValue.File)
+		config.OutboundConfigValue.File = filepath.Join(filepath.Dir(fixedFile), config.OutboundConfigValue.File)
 	}
 
 	return config, err
diff --git a/config/json/json_test.go b/config/json/json_test.go
new file mode 100644
index 00000000..52b10af0
--- /dev/null
+++ b/config/json/json_test.go
@@ -0,0 +1,47 @@
+package json
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/v2ray/v2ray-core/testing/unit"
+)
+
+func TestClientSampleConfig(t *testing.T) {
+	assert := unit.Assert(t)
+
+	// TODO: fix for Windows
+	baseDir := "$GOPATH/src/github.com/v2ray/v2ray-core/release/config"
+
+	config, err := LoadConfig(filepath.Join(baseDir, "vpoint_socks_vmess.json"))
+	assert.Error(err).IsNil()
+
+	assert.Uint16(config.PortValue).Positive()
+	assert.Pointer(config.InboundConfigValue).IsNotNil()
+	assert.Pointer(config.OutboundConfigValue).IsNotNil()
+
+	assert.String(config.InboundConfigValue.ProtocolString).Equals("socks")
+	assert.Int(len(config.InboundConfigValue.Content())).GreaterThan(0)
+
+	assert.String(config.OutboundConfigValue.ProtocolString).Equals("vmess")
+	assert.Int(len(config.OutboundConfigValue.Content())).GreaterThan(0)
+}
+
+func TestServerSampleConfig(t *testing.T) {
+	assert := unit.Assert(t)
+
+	// TODO: fix for Windows
+	baseDir := "$GOPATH/src/github.com/v2ray/v2ray-core/release/config"
+
+	config, err := LoadConfig(filepath.Join(baseDir, "vpoint_vmess_freedom.json"))
+	assert.Error(err).IsNil()
+
+	assert.Uint16(config.PortValue).Positive()
+	assert.Pointer(config.InboundConfigValue).IsNotNil()
+	assert.Pointer(config.OutboundConfigValue).IsNotNil()
+
+	assert.String(config.InboundConfigValue.ProtocolString).Equals("vmess")
+	assert.Int(len(config.InboundConfigValue.Content())).GreaterThan(0)
+
+	assert.String(config.OutboundConfigValue.ProtocolString).Equals("freedom")
+}
diff --git a/testing/unit/assertions.go b/testing/unit/assertions.go
index fe5b2cfc..1b10d1b9 100644
--- a/testing/unit/assertions.go
+++ b/testing/unit/assertions.go
@@ -47,3 +47,7 @@ func (a *Assertion) Error(value error) *ErrorSubject {
 func (a *Assertion) Bool(value bool) *BoolSubject {
 	return NewBoolSubject(NewSubject(a), value)
 }
+
+func (a *Assertion) Pointer(value interface{}) *PointerSubject {
+	return NewPointerSubject(NewSubject(a), value)
+}
diff --git a/testing/unit/pointersubject.go b/testing/unit/pointersubject.go
new file mode 100644
index 00000000..e7ed60bf
--- /dev/null
+++ b/testing/unit/pointersubject.go
@@ -0,0 +1,48 @@
+package unit
+
+import (
+	"fmt"
+)
+
+type PointerSubject struct {
+	*Subject
+	value interface{}
+}
+
+func NewPointerSubject(base *Subject, value interface{}) *PointerSubject {
+	return &PointerSubject{
+		Subject: base,
+		value:   value,
+	}
+}
+
+func (subject *PointerSubject) Named(name string) *PointerSubject {
+	subject.Subject.Named(name)
+	return subject
+}
+
+func (subject *PointerSubject) Fail(verb string, other interface{}) {
+	subject.FailWithMessage(fmt.Sprintf("Not true that %s %s <%v>.", subject.DisplayString(), verb, other))
+}
+
+func (subject *PointerSubject) DisplayString() string {
+	return subject.Subject.DisplayString(fmt.Sprintf("%v", subject.value))
+}
+
+func (subject *PointerSubject) Equals(expectation interface{}) {
+	if subject.value != expectation {
+		subject.Fail("is equal to", expectation)
+	}
+}
+
+func (subject *PointerSubject) IsNil() {
+	if subject.value != nil {
+		subject.FailWithMessage("Not true that " + subject.DisplayString() + " is nil.")
+	}
+}
+
+func (subject *PointerSubject) IsNotNil() {
+	if subject.value == nil {
+		subject.FailWithMessage("Not true that " + subject.DisplayString() + " is not nil.")
+	}
+}
diff --git a/testing/unit/uint16subject.go b/testing/unit/uint16subject.go
index b1a3cace..0d150c38 100644
--- a/testing/unit/uint16subject.go
+++ b/testing/unit/uint16subject.go
@@ -46,3 +46,9 @@ func (subject *Uint16Subject) LessThan(expectation uint16) {
 		subject.Fail("is less than", expectation)
 	}
 }
+
+func (subject *Uint16Subject) Positive() {
+	if subject.value <= 0 {
+		subject.FailWithMessage("Not true that " + subject.DisplayString() + " is positive.")
+	}
+}