Add more formatter tests

2 files changed, 68 insertions, 0 deletions

diff --git a/roundtrip_test.go b/roundtrip_test.go
new file mode 100644
index 0000000..71ca6d0
--- /dev/null
+++ b/roundtrip_test.go
@@ -0,0 +1,54 @@
+// Copyright (C) 2022-2023  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package lowmemjson_test
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"git.lukeshu.com/go/lowmemjson"
+)
+
+type ScanDevicesResult map[string]ScanOneDeviceResult
+
+type ScanOneDeviceResult struct {
+	FoundExtentCSums []SysExtentCSum
+}
+
+type SysExtentCSum struct {
+	Generation int64
+	Sums       SumRun
+}
+
+func TestRoundTrip(t *testing.T) {
+	t.Parallel()
+	dents, err := os.ReadDir(filepath.Join("testdata", "roundtrip"))
+	require.NoError(t, err)
+	for _, dent := range dents {
+		filename := dent.Name()
+		if !strings.HasSuffix(filename, ".json") {
+			continue
+		}
+		t.Run(strings.TrimSuffix(filename, ".json"), func(t *testing.T) {
+			t.Parallel()
+			inBytes, err := os.ReadFile(filepath.Join("testdata", "roundtrip", filename))
+			require.NoError(t, err)
+			var obj ScanDevicesResult
+			require.NoError(t, lowmemjson.NewDecoder(bytes.NewReader(inBytes)).DecodeThenEOF(&obj))
+			var outBytes bytes.Buffer
+			require.NoError(t, lowmemjson.NewEncoder(lowmemjson.NewReEncoder(&outBytes, lowmemjson.ReEncoderConfig{
+				Indent:                "\t",
+				ForceTrailingNewlines: true,
+				CompactIfUnder:        16, //nolint:gomnd // This is what looks nice.
+			})).Encode(obj))
+			require.Equal(t, string(inBytes), outBytes.String())
+		})
+	}
+}
diff --git a/testdata/roundtrip/scandevices.json b/testdata/roundtrip/scandevices.json
new file mode 100644
index 0000000..c62f7df
--- /dev/null
+++ b/testdata/roundtrip/scandevices.json
@@ -0,0 +1,14 @@
+{
+	"dev-1234": {
+		"FoundExtentCSums": [
+			{
+				"Generation": 6596005,
+				"Sums": {
+					"ChecksumSize": 4,
+					"Addr": 52626001920,
+					"Sums": "d69e7384e04333e332f32f8ecfd874ea1ea3f66bd54143f826f740b995105d0e8b2d25a21709109c4930e526a68a89e48d3ebdb6f5191bca3e867eba57110e36d885ca46666168ad782b4fe9af483561"
+				}
+			}
+		]
+	}
+}