Merge pull request #31 from rmg/empty-result-on-empty-bucket

Give empty results on empty bucket queries

.travis.yml

@@ -7,4 +7,4 @@ install:
 
 script:
   - go test -v -covermode=count -coverprofile=coverage.out
-  - $HOME/gopath/bin/goveralls -coverprofile=coverage.out -service=travis-ci -repotoken $COVERALLS_TOKEN
+  - $HOME/gopath/bin/goveralls -coverprofile=coverage.out -service=travis-ci

find_test.go

@@ -633,6 +633,21 @@ func TestFindOnInvalidIndex(t *testing.T) {
 	})
 }
 
+func TestFindOnEmptyBucketWithIndex(t *testing.T) {
+	testWrap(t, func(store *bolthold.Store, t *testing.T) {
+		// DO NOT INSERT DATA
+		var result []ItemTest
+
+		err := store.Find(&result, bolthold.Where("Category").Eq("animal").Index("Category"))
+		if err != nil {
+			t.Fatalf("Find query against a valid index name but an empty data bucket return an error!")
+		}
+		if len(result) > 0 {
+			t.Fatalf("Find query against an empty bucket returned results!")
+		}
+	})
+}
+
 func TestQueryStringPrint(t *testing.T) {
 	q := bolthold.Where("FirstField").Eq("first value").And("SecondField").Gt("Second Value").And("ThirdField").
 		Lt("Third Value").And("FourthField").Ge("FourthValue").And("FifthField").Le("FifthValue").And("SixthField").

query.go

@@ -510,6 +510,13 @@ type record struct {
 
 func runQuery(tx *bolt.Tx, dataType interface{}, query *Query, retrievedKeys keyList, skip int, action func(r *record) error) error {
 	storer := newStorer(dataType)
+
+	bkt := tx.Bucket([]byte(storer.Type()))
+	if bkt == nil || bkt.Stats().KeyN == 0 {
+		// if the bucket doesn't exist or is empty then our job is really easy!
+		return nil
+	}
+
 	if query.index != "" && tx.Bucket(indexBucketName(storer.Type(), query.index)) == nil {
 		return fmt.Errorf("The index %s does not exist", query.index)
 	}