Fix Err fallout for graph/iterator.Materialize iterator

graph/iterator/materialize_iterator_test.go

@@ -0,0 +1,72 @@
+// Copyright 2014 The Cayley Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package iterator
+
+import (
+	"errors"
+	"testing"
+
+	//"github.com/google/cayley/graph"
+)
+
+func TestMaterializeIteratorError(t *testing.T) {
+	retErr := errors.New("unique")
+	errIt := newTestIterator(false, retErr)
+
+	// This tests that we properly return 0 results and the error when the
+	// underlying iterator returns an error.
+	mIt := NewMaterialize(errIt)
+
+	if mIt.Next() != false {
+		t.Errorf("Materialize iterator did not pass through underlying 'false'")
+	}
+	if mIt.Err() != retErr {
+		t.Errorf("Materialize iterator did not pass through underlying Err")
+	}
+}
+
+func TestMaterializeIteratorErrorAbort(t *testing.T) {
+	retErr := errors.New("unique")
+	errIt := newTestIterator(false, retErr)
+
+	// This tests that we properly return 0 results and the error when the
+	// underlying iterator is larger than our 'abort at' value, and then
+	// returns an error.
+	or := NewOr()
+	or.AddSubIterator(NewInt64(1, int64(abortMaterializeAt+1)))
+	or.AddSubIterator(errIt)
+
+	mIt := NewMaterialize(or)
+
+	// Should get all the underlying values...
+	for i := 0; i < abortMaterializeAt+1; i++ {
+		if !mIt.Next() {
+			t.Errorf("Materialize iterator returned spurious 'false' on iteration %d", i)
+			return
+		}
+		if mIt.Err() != nil {
+			t.Errorf("Materialize iterator returned non-nil Err on iteration %d", i)
+			return
+		}
+	}
+
+	// ... and then the error value
+	if mIt.Next() != false {
+		t.Errorf("Materialize iterator did not pass through underlying 'false'")
+	}
+	if mIt.Err() != retErr {
+		t.Errorf("Materialize iterator did not pass through underlying Err")
+	}
+}