consul config source support 1st-level array

Check whetehr the 1st level encoded json is array or not, to
support 1st level array in consul config.

During debug, i suspected the incapability of arrray is caused by
json reader, so i added test for array. I think it makes no harm
to also check that in.

config/reader/json/values_test.go

@@ -1,39 +1,85 @@
 package json
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/micro/go-micro/config/source"
 )
 
 func TestValues(t *testing.T) {
-	data := []byte(`{"foo": "bar", "baz": {"bar": "cat"}}`)
-
+	emptyStr := ""
 	testData := []struct {
-		path  []string
-		value string
+		csdata   []byte
+		path     []string
+		accepter interface{}
+		value    interface{}
 	}{
 		{
+			[]byte(`{"foo": "bar", "baz": {"bar": "cat"}}`),
 			[]string{"foo"},
+			emptyStr,
 			"bar",
 		},
 		{
+			[]byte(`{"foo": "bar", "baz": {"bar": "cat"}}`),
 			[]string{"baz", "bar"},
+			emptyStr,
 			"cat",
 		},
 	}
 
-	values, err := newValues(&source.ChangeSet{
-		Data: data,
-	})
+	for idx, test := range testData {
+		values, err := newValues(&source.ChangeSet{
+			Data: test.csdata,
+		})
+		if err != nil {
+			t.Fatal(err)
+		}
 
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	for _, test := range testData {
-		if v := values.Get(test.path...).String(""); v != test.value {
-			t.Fatalf("Expected %s got %s for path %v", test.value, v, test.path)
+		err = values.Get(test.path...).Scan(&test.accepter)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if test.accepter != test.value {
+			t.Fatalf("No.%d Expected %v got %v for path %v", idx, test.value, test.accepter, test.path)
+		}
+	}
+}
+
+func TestStructArray(t *testing.T) {
+	type T struct {
+		Foo string
+	}
+
+	emptyTSlice := []T{}
+
+	testData := []struct {
+		csdata   []byte
+		accepter []T
+		value    []T
+	}{
+		{
+			[]byte(`[{"foo": "bar"}]`),
+			emptyTSlice,
+			[]T{T{Foo: "bar"}},
+		},
+	}
+
+	for idx, test := range testData {
+		values, err := newValues(&source.ChangeSet{
+			Data: test.csdata,
+		})
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		err = values.Get().Scan(&test.accepter)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !reflect.DeepEqual(test.accepter, test.value) {
+			t.Fatalf("No.%d Expected %v got %v", idx, test.value, test.accepter)
 		}
 	}
 }