From 6ba280e75ddcb9ccf931322a1bad3c9d8fa0d0d3 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Sun, 15 Jan 2017 20:06:08 -0500
Subject: [PATCH] add unit test for basic undo/redo of erases

---
 test/src/test_Buffer.cc | 49 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/test/src/test_Buffer.cc b/test/src/test_Buffer.cc
index 49c1873..2b6e193 100644
--- a/test/src/test_Buffer.cc
+++ b/test/src/test_Buffer.cc
@@ -193,3 +193,52 @@ TEST(BufferTest, allows_undo_and_redo_of_inserts)
     EXPECT_EQ(ss("12abc\nd3ef$\nghi\n"), b.get_string());
     EXPECT_EQ(C('d'), **it);
 }
+
+TEST(BufferTest, allows_undo_and_redo_of_erases)
+{
+    std::string s("abc\ndef\nghi\n");
+    Buffer b((const uint8_t *)&s[0], s.size());
+    auto it = b.add_cursor();
+
+    b.erase_code_point(*it);
+    EXPECT_EQ(ss("bc\ndef\nghi\n"), b.get_string());
+    EXPECT_EQ(C('b'), **it);
+
+    it->go_next_line();
+    it->go_right_in_line(false);
+    b.erase_code_point(*it);
+    EXPECT_EQ(ss("bc\ndf\nghi\n"), b.get_string());
+    EXPECT_EQ(C('f'), **it);
+
+    it->go_end_of_line(true);
+    b.erase_code_point(*it);
+    EXPECT_EQ(ss("bc\ndfghi\n"), b.get_string());
+    EXPECT_EQ(C('g'), **it);
+
+    it->go_left_in_line();
+    EXPECT_EQ(C('f'), **it);
+
+    b.undo();
+    EXPECT_EQ(ss("bc\ndf\nghi\n"), b.get_string());
+    EXPECT_EQ(C('f'), **it);
+
+    b.undo();
+    EXPECT_EQ(ss("bc\ndef\nghi\n"), b.get_string());
+    EXPECT_EQ(C('f'), **it);
+
+    b.undo();
+    EXPECT_EQ(ss("abc\ndef\nghi\n"), b.get_string());
+    EXPECT_EQ(C('f'), **it);
+
+    b.redo();
+    EXPECT_EQ(ss("bc\ndef\nghi\n"), b.get_string());
+    EXPECT_EQ(C('f'), **it);
+
+    b.redo();
+    EXPECT_EQ(ss("bc\ndf\nghi\n"), b.get_string());
+    EXPECT_EQ(C('f'), **it);
+
+    b.redo();
+    EXPECT_EQ(ss("bc\ndfghi\n"), b.get_string());
+    EXPECT_EQ(C('f'), **it);
+}