Add Buffer::erase_range()

test/src/test_Buffer.cc

@@ -133,6 +133,37 @@ TEST(BufferTest, allows_inserting_and_erasing_characters)
     b.exit_insert_mode();
 }
 
+TEST(BufferTest, allows_erasing_ranges)
+{
+    std::string s("abc\ndef\n");
+    Buffer b((const uint8_t *)&s[0], s.size());
+    auto it = b.add_iterator();
+    auto it2 = b.add_iterator();
+    it2->go_next_line();
+
+    /* Invalid tests. */
+    b.erase_range(b.end(), b.end());
+    EXPECT_EQ(ss("abc\ndef\n"), b.get_string());
+    b.erase_range(*it, b.begin());
+    EXPECT_EQ(ss("abc\ndef\n"), b.get_string());
+
+    EXPECT_EQ(C('a'), **it);
+    EXPECT_EQ(C('d'), **it2);
+    b.erase_range(*it, *it2);
+    EXPECT_EQ(ss("def\n"), b.get_string());
+    EXPECT_EQ(*it, *it2);
+    EXPECT_EQ(C('d'), **it);
+    while (it2->valid())
+    {
+        it2->go_forward();
+    }
+    EXPECT_EQ(C('d'), **it);
+    b.erase_range(*it, *it2);
+    EXPECT_EQ(ss(""), b.get_string());
+    EXPECT_FALSE(it->valid());
+    EXPECT_FALSE(it2->valid());
+}
+
 TEST(BufferTest, adds_a_newline_after_inserted_character_when_inserting_in_an_empty_buffer)
 {
     Buffer b;