diff --git a/db/load_test.go b/db/load_test.go
new file mode 100644
index 0000000..17ed6c5
--- /dev/null
+++ b/db/load_test.go
@@ -0,0 +1,81 @@
+package db
+
+import (
+	"bytes"
+	"compress/bzip2"
+	"compress/gzip"
+	"testing"
+)
+
+var testDecompressor = []struct {
+	message string
+	input   []byte
+	expect  []byte
+	err     error
+	readErr error
+}{
+	{
+		message: "text input",
+		input:   []byte("cayley data\n"),
+		err:     nil,
+		expect:  []byte("cayley data\n"),
+		readErr: nil,
+	},
+	{
+		message: "gzip input",
+		input: []byte{
+			0x1f, 0x8b, 0x08, 0x00, 0x5c, 0xbc, 0xcd, 0x53, 0x00, 0x03, 0x4b, 0x4e, 0xac, 0xcc, 0x49, 0xad,
+			0x54, 0x48, 0x49, 0x2c, 0x49, 0xe4, 0x02, 0x00, 0x03, 0xe1, 0xfc, 0xc3, 0x0c, 0x00, 0x00, 0x00,
+		},
+		err:     nil,
+		expect:  []byte("cayley data\n"),
+		readErr: nil,
+	},
+	{
+		message: "bzip2 input",
+		input: []byte{
+			0x42, 0x5a, 0x68, 0x39, 0x31, 0x41, 0x59, 0x26, 0x53, 0x59, 0xb5, 0x4b, 0xe3, 0xc4, 0x00, 0x00,
+			0x02, 0xd1, 0x80, 0x00, 0x10, 0x40, 0x00, 0x2e, 0x04, 0x04, 0x20, 0x20, 0x00, 0x31, 0x06, 0x4c,
+			0x41, 0x4c, 0x1e, 0xa7, 0xa9, 0x2a, 0x18, 0x26, 0xb1, 0xc2, 0xee, 0x48, 0xa7, 0x0a, 0x12, 0x16,
+			0xa9, 0x7c, 0x78, 0x80,
+		},
+		err:     nil,
+		expect:  []byte("cayley data\n"),
+		readErr: nil,
+	},
+	{
+		message: "bad gzip input",
+		input:   []byte{0x1f, 0x8b, 'c', 'a', 'y', 'l', 'e', 'y', ' ', 'd', 'a', 't', 'a', '\n'},
+		err:     gzip.ErrHeader,
+		expect:  nil,
+		readErr: nil,
+	},
+	{
+		message: "bad bzip2 input",
+		input:   []byte{0x42, 0x5a, 0x68, 'c', 'a', 'y', 'l', 'e', 'y', ' ', 'd', 'a', 't', 'a', '\n'},
+		err:     nil,
+		expect:  nil,
+		readErr: bzip2.StructuralError("invalid compression level"),
+	},
+}
+
+func TestDecompressor(t *testing.T) {
+	for _, test := range testDecompressor {
+		buf := bytes.NewReader(test.input)
+		r, err := decompressor(buf)
+		if err != test.err {
+			t.Fatalf("Unexpected error for %s, got:%v expect:%v", test.message, err, test.err)
+		}
+		if err != nil {
+			continue
+		}
+		p := make([]byte, len(test.expect)*2)
+		n, err := r.Read(p)
+		if err != test.readErr {
+			t.Fatalf("Unexpected error for reading %s, got:%v expect:%v", test.message, err, test.err)
+		}
+		if bytes.Compare(p[:n], test.expect) != 0 {
+			t.Errorf("Unexpected read result for %s, got:%q expect:%q", test.message, p[:n], test.expect)
+		}
+	}
+}