Fix to the GUID stability issue introduced by anchors

Fixed the stability issued that introduced comparison errors. Closes
#36 and also introduce new tests to validate the behavior.

Author: xllora

bql/planner/data_access.go

@@ -336,7 +336,6 @@ func simpleFetch(ctx context.Context, gs []storage.Graph, cls *semantic.GraphCla
 				aErr error
 				wg   sync.WaitGroup
 			)
-
 			wg.Add(2)
 			ts := make(chan *triple.Triple, chanSize)
 			go func() {

triple/triple.go

@@ -276,7 +276,7 @@ func (t *Triple) GUID() string {
 
 	// Object.
 	if t.o.p == nil {
-		buffer.WriteString(t.o.p.String())
+		buffer.WriteString(t.o.String())
 	} else {
 		ta, err := t.o.p.TimeAnchor()
 		if err != nil {

triple/triple_test.go

@@ -101,7 +101,43 @@ func TestGUID(t *testing.T) {
 	}{
 		{
 			"/some/type<some id>\t\"foo\"@[]\t/some/type<some id>",
-			"/some/type<some id>\t\"foo\"@[]\t\"bar\"@[]",
+			"/some/type<some id>\t\"foo\"@[]\t/some/type<some id>",
+		},
+		{
+			"/some/type<some id>\t\"foo\"@[2015-01-01T00:00:00-09:00]\t/some/type<some id>",
+			"/some/type<some id>\t\"foo\"@[2015-01-01T00:00:00-09:00]\t/some/type<some id>",
+		},
+		{
+			"/some/type<some id>\t\"foo\"@[2015-01-01T00:00:00-09:00]\t/some/type<some id>",
+			"/some/type<some id>\t\"foo\"@[2015-01-01T01:00:00-08:00]\t/some/type<some id>",
+		},
+		{
+			"/some/type<some id>\t\"foo\"@[]\t\"bar\"@[2015-01-01T00:00:00-09:00]",
+			"/some/type<some id>\t\"foo\"@[]\t\"bar\"@[2015-01-01T00:00:00-09:00]",
+		},
+		{
+			"/some/type<some id>\t\"foo\"@[]\t\"bar\"@[2015-01-01T00:00:00-09:00]",
+			"/some/type<some id>\t\"foo\"@[]\t\"bar\"@[2015-01-01T01:00:00-08:00]",
+		},
+		{
+			"/some/type<some id>\t\"foo\"@[]\t\"true\"^^type:bool",
+			"/some/type<some id>\t\"foo\"@[]\t\"true\"^^type:bool",
+		},
+		{
+			"/some/type<some id>\t\"foo\"@[]\t\"1\"^^type:int64",
+			"/some/type<some id>\t\"foo\"@[]\t\"1\"^^type:int64",
+		},
+		{
+			"/some/type<some id>\t\"foo\"@[]\t\"1\"^^type:float64",
+			"/some/type<some id>\t\"foo\"@[]\t\"1\"^^type:float64",
+		},
+		{
+			"/some/type<some id>\t\"foo\"@[]\t\"text\"^^type:text",
+			"/some/type<some id>\t\"foo\"@[]\t\"text\"^^type:text",
+		},
+		{
+			"/some/type<some id>\t\"foo\"@[]\t\"[0 0 0]\"^^type:blob",
+			"/some/type<some id>\t\"foo\"@[]\t\"[0 0 0]\"^^type:blob",
 		},
 	}
 	for _, entry := range testTable {