feat(firestore): implement limitToLast

firestore/examples_test.go

@@ -432,27 +432,6 @@ func ExampleQuery_Documents() {
 	_ = iter2 // TODO: Use iter2.
 }
 
-func ExampleQuery_GetAll() {
-	ctx := context.Background()
-	client, err := firestore.NewClient(ctx, "project-id")
-	if err != nil {
-		// TODO: Handle error.
-	}
-	defer client.Close()
-
-	q := client.Collection("States").Select("pop").
-		Where("pop", ">", 10).
-		OrderBy("pop", firestore.Desc).
-		Limit(10)
-
-	docs, err := q.GetAll(ctx)
-	if err != nil {
-		// TODO: Handle error.
-	}
-	// docs is a slice with DocumentSnapshots.
-	fmt.Println(docs)
-}
-
 // This example is just like the one above, but illustrates
 // how to use the XXXPath methods of Query for field paths
 // that can't be expressed as a dot-separated string.

firestore/integration_test.go

@@ -657,6 +657,7 @@ func TestIntegration_QueryDocuments(t *testing.T) {
 		{q.StartAfter(1), wants[2:]},
 		{q.EndAt(1), wants[:2]},
 		{q.EndBefore(1), wants[:1]},
+		{q.LimitToLast(2), wants[1:]},
 	} {
 		gotDocs, err := test.q.Documents(ctx).GetAll()
 		if err != nil {
@@ -709,83 +710,9 @@ func TestIntegration_QueryDocuments_LimitToLast_Fail(t *testing.T) {
 	ctx := context.Background()
 	coll := integrationColl(t)
 	q := coll.Select("q").OrderBy("q", Asc).LimitToLast(1)
-	gotDocs, err := q.Documents(ctx).GetAll()
+	got, err := q.Documents(ctx).Next()
 	if err == nil {
-		t.Errorf("got %v docs, want error", len(gotDocs))
-	}
-}
-
-func TestIntegration_QueryGetAll(t *testing.T) {
-	ctx := context.Background()
-	coll := integrationColl(t)
-	h := testHelper{t}
-	var wants []map[string]interface{}
-	for i := 0; i < 3; i++ {
-		doc := coll.NewDoc()
-		// To support running this test in parallel with the others, use a field name
-		// that we don't use anywhere else.
-		h.mustCreate(doc, map[string]interface{}{"q": i, "x": 1})
-		wants = append(wants, map[string]interface{}{"q": int64(i)})
-	}
-	q := coll.Select("q").OrderBy("q", Asc)
-	for i, test := range []struct {
-		q    Query
-		want []map[string]interface{}
-	}{
-		{q, wants},
-		{q.Where("q", ">", 1), wants[2:]},
-		{q.WherePath([]string{"q"}, ">", 1), wants[2:]},
-		{q.Offset(1).Limit(1), wants[1:2]},
-		{q.StartAt(1), wants[1:]},
-		{q.StartAfter(1), wants[2:]},
-		{q.EndAt(1), wants[:2]},
-		{q.EndBefore(1), wants[:1]},
-		{q.LimitToLast(2), wants[1:]},
-	} {
-		gotDocs, err := test.q.GetAll(ctx)
-		if err != nil {
-			t.Errorf("#%d: %+v: %v", i, test.q, err)
-			continue
-		}
-		if len(gotDocs) != len(test.want) {
-			t.Errorf("#%d: %+v: got %d docs, want %d", i, test.q, len(gotDocs), len(test.want))
-			continue
-		}
-		for j, g := range gotDocs {
-			if got, want := g.Data(), test.want[j]; !testEqual(got, want) {
-				t.Errorf("#%d: %+v, #%d: got\n%+v\nwant\n%+v", i, test.q, j, got, want)
-			}
-		}
-	}
-	_, err := coll.Select("q").Where("x", "==", 1).OrderBy("q", Asc).GetAll(ctx)
-	codeEq(t, "Where and OrderBy on different fields without an index", codes.FailedPrecondition, err)
-
-	// Using the collection itself as the query should return the full documents.
-	allDocs, err := coll.GetAll(ctx)
-	if err != nil {
-		t.Fatal(err)
-	}
-	seen := map[int64]bool{} // "q" values we see.
-	for _, d := range allDocs {
-		data := d.Data()
-		q, ok := data["q"]
-		if !ok {
-			// A document from another test.
-			continue
-		}
-		if seen[q.(int64)] {
-			t.Errorf("%v: duplicate doc", data)
-		}
-		seen[q.(int64)] = true
-		if data["x"] != int64(1) {
-			t.Errorf("%v: wrong or missing 'x'", data)
-		}
-		if len(data) != 2 {
-			t.Errorf("%v: want two keys", data)
-		}
-	}
-	if got, want := len(seen), len(wants); got != want {
-		t.Errorf("got %d docs with 'q', want %d", len(seen), len(wants))
+		t.Errorf("got %v doc, want error", got)
 	}
 }
 

firestore/query.go

@@ -579,57 +579,18 @@ func trunc32(i int) int32 {
 	return int32(i)
 }
 
-// GetAll returns an array of query's resulting documents.
-func (q Query) GetAll(ctx context.Context) ([]*DocumentSnapshot, error) {
-	limitedToLast := q.limitToLast
-
-	if q.limitToLast {
-		// Flip order statements before posting a request.
-		for i := range q.orders {
-			if q.orders[i].dir == Asc {
-				q.orders[i].dir = Desc
-			} else {
-				q.orders[i].dir = Asc
-			}
-		}
-		// Swap cursors.
-		q.startVals, q.endVals = q.endVals, q.startVals
-		q.startDoc, q.endDoc = q.endDoc, q.startDoc
-		q.startBefore, q.endBefore = q.endBefore, q.startBefore
-
-		q.limitToLast = false
-	}
-	docs, err := q.Documents(ctx).GetAll()
-	if err != nil {
-		return nil, err
-	}
-	if limitedToLast {
-		// Flip docs order before return.
-		for i, j := 0, len(docs)-1; i < j; {
-			docs[i], docs[j] = docs[j], docs[i]
-			i++
-			j--
-		}
-	}
-	return docs, nil
-}
-
 // Documents returns an iterator over the query's resulting documents.
 func (q Query) Documents(ctx context.Context) *DocumentIterator {
-	if q.limitToLast {
-		return &DocumentIterator{
-			err: errors.New("firestore: queries that include limitToLast constraints cannot be streamed. Use Query.GetAll() instead"),
-		}
-	}
 	return &DocumentIterator{
-		iter: newQueryDocumentIterator(withResourceHeader(ctx, q.c.path()), &q, nil),
+		iter: newQueryDocumentIterator(withResourceHeader(ctx, q.c.path()), &q, nil), q: q,
 	}
 }
 
 // DocumentIterator is an iterator over documents returned by a query.
 type DocumentIterator struct {
 	iter docIterator
 	err  error
+	q    Query
 }
 
 // Unexported interface so we can have two different kinds of DocumentIterator: one
@@ -649,6 +610,9 @@ func (it *DocumentIterator) Next() (*DocumentSnapshot, error) {
 	if it.err != nil {
 		return nil, it.err
 	}
+	if it.q.limitToLast {
+		return nil, errors.New("firestore: queries that include limitToLast constraints cannot be streamed. Use DocumentIterator.GetAll() instead")
+	}
 	ds, err := it.iter.next()
 	if err != nil {
 		it.err = err
@@ -672,6 +636,25 @@ func (it *DocumentIterator) Stop() {
 // It is not necessary to call Stop on the iterator after calling GetAll.
 func (it *DocumentIterator) GetAll() ([]*DocumentSnapshot, error) {
 	defer it.Stop()
+
+	q := &it.q
+	limitedToLast := q.limitToLast
+	if q.limitToLast {
+		// Flip order statements before posting a request.
+		for i := range q.orders {
+			if q.orders[i].dir == Asc {
+				q.orders[i].dir = Desc
+			} else {
+				q.orders[i].dir = Asc
+			}
+		}
+		// Swap cursors.
+		q.startVals, q.endVals = q.endVals, q.startVals
+		q.startDoc, q.endDoc = q.endDoc, q.startDoc
+		q.startBefore, q.endBefore = q.endBefore, q.startBefore
+
+		q.limitToLast = false
+	}
 	var docs []*DocumentSnapshot
 	for {
 		doc, err := it.Next()
@@ -683,6 +666,14 @@ func (it *DocumentIterator) GetAll() ([]*DocumentSnapshot, error) {
 		}
 		docs = append(docs, doc)
 	}
+	if limitedToLast {
+		// Flip docs order before return.
+		for i, j := 0, len(docs)-1; i < j; {
+			docs[i], docs[j] = docs[j], docs[i]
+			i++
+			j--
+		}
+	}
 	return docs, nil
 }