fix(Query): Fix cascade pagination with 0 offset. (#7636)

hypermodeinc · Mar 25, 2021 · f091ce5 · f091ce5
1 parent df7d9f8
commit f091ce5
Show file tree

Hide file tree

Showing 2 changed files with 17 additions and 3 deletions.
diff --git a/query/query.go b/query/query.go
@@ -1394,7 +1394,7 @@ func (sg *SubGraph) populateVarMap(doneVars map[string]varValue, sgPath []*SubGr
 		child.updateUidMatrix()
 
 		// Apply pagination after the @cascade.
-		if len(child.Params.Cascade.Fields) > 0 && child.Params.Cascade.First != 0 && child.Params.Cascade.Offset != 0 {
+		if len(child.Params.Cascade.Fields) > 0 && (child.Params.Cascade.First != 0 || child.Params.Cascade.Offset != 0) {
 			for i := 0; i < len(child.uidMatrix); i++ {
 				start, end := x.PageRange(child.Params.Cascade.First, child.Params.Cascade.Offset, len(child.uidMatrix[i].Uids))
 				child.uidMatrix[i].Uids = child.uidMatrix[i].Uids[start:end]
@@ -2435,7 +2435,8 @@ func (sg *SubGraph) applyOrderAndPagination(ctx context.Context) error {
 		}
 	}
 
-	if sg.Params.Count == 0 {
+	// if the @cascade directive is used then retrieve all the results.
+	if sg.Params.Count == 0 && len(sg.Params.Cascade.Fields) == 0 {
 		// Only retrieve up to 1000 results by default.
 		sg.Params.Count = 1000
 	}
@@ -2885,7 +2886,7 @@ func (req *Request) ProcessQuery(ctx context.Context) (err error) {
 			// first time at the root here.
 
 			// Apply pagination at the root after @cascade.
-			if len(sg.Params.Cascade.Fields) > 0 && sg.Params.Cascade.First != 0 && sg.Params.Cascade.Offset != 0 {
+			if len(sg.Params.Cascade.Fields) > 0 && (sg.Params.Cascade.First != 0 || sg.Params.Cascade.Offset != 0) {
 				sg.updateUidMatrix()
 				for i := 0; i < len(sg.uidMatrix); i++ {
 					start, end := x.PageRange(sg.Params.Cascade.First, sg.Params.Cascade.Offset, len(sg.uidMatrix[i].Uids))

diff --git a/query/query0_test.go b/query/query0_test.go
@@ -520,6 +520,19 @@ func TestCascadeWithPaginationAtRoot(t *testing.T) {
 	require.JSONEq(t, `{"data":{"me":[{"name":"Andrea","alive":false}]}}`, js)
 }
 
+func TestCascadeWithPaginationAndOffsetZero(t *testing.T) {
+	query := `
+	{
+		me(func: type(Person), first: 1, offset: 0) @cascade{
+		  name
+		  alive
+		}
+	  }
+	`
+	js := processQueryNoErr(t, query)
+	require.JSONEq(t, `{"data":{"me":[{"name":"Rick Grimes","alive":true}]}}`, js)
+}
+
 func TestLevelBasedFacetVarAggSum(t *testing.T) {
 	query := `
 		{