fixes

jq/index.go

@@ -43,6 +43,8 @@ func (f *Index) Next(w, r []byte, st int, state State) (_ []byte, i int, _ State
 		if err != nil {
 			return w[:wreset], i, nil, pe(err, i)
 		}
+
+		return w, i, nil, nil
 	}
 
 	var stateok *indexState

jq/index_test.go

@@ -20,12 +20,7 @@ func TestIndex(tb *testing.T) {
 		assert.Equal(tb, j == 0, state == nil)
 
 		w, i, state, err = f.Next(w[:0], r, i, state)
-		if !assert.NoError(tb, err) {
-			pref := r[:i]
-			suff := r[i:]
-
-			tb.Logf("%s|%s", pref, suff)
-		}
+		assertBytesErr(tb, r, i, err)
 
 		assert.Equal(tb, exp, string(w))
 
@@ -35,17 +30,22 @@ func TestIndex(tb *testing.T) {
 	}
 
 	w, i, state, err = f.Next(w[:0], r, i, state)
-	if !assert.NoError(tb, err) {
-		pref := r[:i]
-		suff := r[i:]
-
-		tb.Logf("%s|%s", pref, suff)
-	}
+	assertBytesErr(tb, r, i, err)
 
 	assert.Nil(tb, state)
 	assert.Equal(tb, len(r), i)
 }
 
+func TestIndexEmpty(tb *testing.T) {
+	r := []byte(`{"results":[],"key":"b"}`)
+	f := NewIndex()
+
+	w, i, err := NextAll(f, nil, r, 0, nil)
+	assertBytesErr(tb, r, i, err)
+	assert.Equal(tb, len(r), i)
+	assert.Equal(tb, r, w)
+}
+
 func TestIndexIterEmpty(tb *testing.T) {
 	var w []byte
 	r := []byte(`{"a":[],"b":{}}`)
@@ -64,3 +64,14 @@ func TestIndexIterEmpty(tb *testing.T) {
 	assert.Nil(tb, state)
 	assert.Len(tb, w, 0)
 }
+
+func assertBytesErr(tb *testing.T, r []byte, i int, err error) {
+	if assert.NoError(tb, err) {
+		return
+	}
+
+	pref := r[:i]
+	suff := r[i:]
+
+	tb.Logf("%s|%s", pref, suff)
+}

jq/select.go

@@ -7,7 +7,6 @@ import (
 type (
 	Select struct {
 		Filter Filter
-		Buf    []byte
 	}
 
 	Map struct {
@@ -17,33 +16,50 @@ type (
 	}
 )
 
+func NewSelect(f Filter) *Select { return &Select{Filter: f} }
+
 func (f *Select) Next(w, r []byte, st int, state State) (_ []byte, i int, _ State, err error) {
 	var p json.Decoder
 
+	wreset := len(w)
+
 	raw, i, err := p.Raw(r, st)
 	if err != nil {
 		return w, i, state, err
 	}
 
+	if f.Filter == nil {
+		ok, _, err := IsTrue(raw, 0)
+		if err != nil {
+			return w, st, state, err
+		}
+
+		if ok {
+			w = append(w, raw...)
+		}
+
+		return w, i, nil, nil
+	}
+
 	ff := cfilter(f.Filter, Dot{})
 
 	var sub State
 	var ok bool
 
 	for {
-		f.Buf, i, sub, err = ff.Next(f.Buf[:0], r, st, sub)
+		w, i, sub, err = ff.Next(w[:wreset], r, st, sub)
 		if err != nil {
 			return w, i, state, err
 		}
 
-		if len(f.Buf) == 0 && sub == nil {
+		if len(w[wreset:]) == 0 && sub == nil {
 			break
 		}
-		if len(f.Buf) == 0 {
+		if len(w[wreset:]) == 0 {
 			continue
 		}
 
-		ok, _, err = IsTrue(f.Buf, 0)
+		ok, _, err = IsTrue(w[wreset:], 0)
 		//	log.Printf("select istrue %v %v <- %q", ok, err, f.Buf)
 		if err != nil {
 			return w, i, state, err
@@ -57,6 +73,8 @@ func (f *Select) Next(w, r []byte, st int, state State) (_ []byte, i int, _ Stat
 		}
 	}
 
+	w = w[:wreset]
+
 	if ok {
 		w = append(w, raw...)
 	}

jq/select_test.go

@@ -17,7 +17,7 @@ func TestSelect(t *testing.T) {
 	for _, exp := range []string{
 		"1", ``, `"a"`, `[4]`, `{"b":true}`,
 	} {
-		w, i, state, err = (&Select{}).Next(w[:0], []byte(data), i, state)
+		w, i, state, err = NewSelect(nil).Next(w[:0], []byte(data), i, state)
 		assert.NoError(t, err)
 		//	assert.Len(t, data, i)
 		assert.Equal(t, exp, string(w))