cleaner testing, leveldb can sort and limit

leveldb_test.go

@@ -0,0 +1,70 @@
+package storage
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strconv"
+	"testing"
+)
+
+func TestLevelDBListLimitedAscending(t *testing.T) {
+	d, err := ioutil.TempDir(os.TempDir(), "leveldb.list.test.*")
+	if err != nil {
+		t.Fatal(err)
+	}
+	db, err := NewLevelDB(d)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	db.Set("key", []byte("hi"), "bad")
+	n := 20
+	for i := 0; i < n; i++ {
+		db.Set(fmt.Sprintf("%02d", i), []byte(strconv.Itoa(i)), "good")
+	}
+
+	if list, err := db.List([]string{}); err != nil {
+		t.Error(err)
+	} else if len(list) != 0 {
+		t.Error(len(list), list)
+	}
+
+	if list, err := db.List([]string{""}); err != nil {
+		t.Error(err)
+	} else if len(list) != n+1 {
+		t.Error(len(list), list)
+	}
+
+	if list, err := db.List([]string{"good"}); err != nil {
+		t.Error(err)
+	} else if len(list) != n {
+		t.Error(len(list), list)
+	}
+
+	if list, err := db.List([]string{"good"}, "10"); err != nil {
+		t.Error(err)
+	} else if len(list) != n-10 {
+		t.Error(len(list), list)
+	}
+
+	if list, err := db.List([]string{"good"}, "10", "15"); err != nil {
+		t.Error(err)
+	} else if len(list) != 15-10+1 {
+		t.Error(len(list), list)
+	}
+
+	if list, err := db.List([]string{"good"}, "10", "15", "2"); err != nil {
+		t.Error(err)
+	} else if len(list) != 2 {
+		t.Error(len(list), list)
+	}
+
+	if list, err := db.List([]string{"good"}, "10", "15", "2", "-"); err != nil {
+		t.Error(err)
+	} else if len(list) != 2 {
+		t.Error(len(list), list)
+	} else if list[1] > list[0] {
+		t.Errorf("not desc: %v", list)
+	}
+}