From 80540a662a218299ec74bba7212f69428a7f1504 Mon Sep 17 00:00:00 2001
From: nxshock <nxshock@gmail.com>
Date: Wed, 7 Dec 2022 19:20:38 +0500
Subject: [PATCH] Add test for backup with deleted records

---
 README.md   |  1 -
 zkv_test.go | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 12eed2b..b66f815 100644
--- a/README.md
+++ b/README.md
@@ -66,6 +66,5 @@ File is log stuctured list of commands:
 
 ## TODO
 
-- [ ] Add delete records test for `Backup()` method
 - [ ] Test [seekable zstd streams](https://github.com/SaveTheRbtz/zstd-seekable-format-go)
 - [ ] Implement optional separate index file to speedup store initialization
diff --git a/zkv_test.go b/zkv_test.go
index 1fc3983..a252f9d 100644
--- a/zkv_test.go
+++ b/zkv_test.go
@@ -274,3 +274,58 @@ func TestBackupBasic(t *testing.T) {
 	assert.NoError(t, err)
 
 }
+
+func TestBackupWithDeletedRecords(t *testing.T) {
+	const filePath = "TestBackupWithDeletedRecords.zkv"
+	const newFilePath = "TestBackupWithDeletedRecords2.zkv"
+	const recordCount = 100
+	defer os.Remove(filePath)
+	defer os.Remove(newFilePath)
+
+	db, err := Open(filePath)
+	assert.NoError(t, err)
+
+	for i := 1; i <= recordCount; i++ {
+		err = db.Set(i, i)
+		assert.NoError(t, err)
+	}
+
+	err = db.Flush()
+	assert.NoError(t, err)
+
+	for i := 1; i <= recordCount; i++ {
+		if i%2 == 1 {
+			continue
+		}
+
+		err = db.Delete(i)
+		assert.NoError(t, err)
+	}
+
+	err = db.Backup(newFilePath)
+	assert.NoError(t, err)
+
+	err = db.Close()
+	assert.NoError(t, err)
+
+	db, err = Open(newFilePath)
+	assert.NoError(t, err)
+
+	assert.Len(t, db.dataOffset, recordCount/2)
+
+	for i := 1; i <= recordCount; i++ {
+		var gotValue int
+
+		err = db.Get(i, &gotValue)
+		if i%2 == 0 {
+			assert.ErrorIs(t, err, ErrNotExists)
+		} else {
+			assert.NoError(t, err)
+			assert.Equal(t, i, gotValue)
+		}
+	}
+
+	err = db.Close()
+	assert.NoError(t, err)
+
+}