From b89f3486024c3d2c79d06f5f840d2033c5aa691a Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Tue, 29 Aug 2017 23:20:42 -0400
Subject: [PATCH] add some initial BufferView unit tests

---
 src/core/BufferView.cc      |  6 ++++
 test/src/test_BufferView.cc | 68 +++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)

diff --git a/src/core/BufferView.cc b/src/core/BufferView.cc
index 32bc785..8464d01 100644
--- a/src/core/BufferView.cc
+++ b/src/core/BufferView.cc
@@ -43,6 +43,12 @@ void BufferView::iter_lines(
                 break;
         }
     }
+    else
+    {
+        m_cursor_screen_row = 0;
+        m_cursor_screen_column = 0;
+        m_cursor_virtual_column = 0;
+    }
 }
 
 /**************************************************************************
diff --git a/test/src/test_BufferView.cc b/test/src/test_BufferView.cc
index 4375adf..d43dd72 100644
--- a/test/src/test_BufferView.cc
+++ b/test/src/test_BufferView.cc
@@ -20,6 +20,11 @@ static std::shared_ptr<Buffer> buffer1()
     return std::make_shared<Buffer>((const uint8_t *)data, strlen(data));
 }
 
+static std::shared_ptr<Buffer> buffer_empty()
+{
+    return std::make_shared<Buffer>(nullptr, 0u);
+}
+
 class MyCharacterWidthDeterminer : public CharacterWidthDeterminer
 {
     int operator()(uint32_t character)
@@ -51,6 +56,23 @@ static int LineNumber(const Buffer::Iterator & iterator)
     return line_number;
 }
 
+TEST(BufferViewTest, iter_lines_does_not_call_callback_for_empty_buffer)
+{
+    std::shared_ptr<Buffer> b = buffer_empty();
+    std::shared_ptr<Buffer::Iterator> iterator = b->add_iterator();
+    BufferView bv(b, iterator, Cwd);
+    bv.resize(40, 8);
+    int times_called = 0;
+    bv.iter_lines([&times_called](int row_offset, const Buffer::Iterator & iterator) -> bool {
+            times_called++;
+            return true;
+            });
+    EXPECT_EQ(0, times_called);
+    EXPECT_EQ(0, bv.cursor_screen_row());
+    EXPECT_EQ(0, bv.cursor_screen_column());
+    EXPECT_EQ(0, bv.cursor_virtual_column());
+}
+
 TEST(BufferViewTest, iterates_through_screen_lines_with_no_wrapping)
 {
     std::shared_ptr<Buffer> b = buffer1();
@@ -64,4 +86,50 @@ TEST(BufferViewTest, iterates_through_screen_lines_with_no_wrapping)
             return true;
             });
     EXPECT_EQ(8, times_called);
+    EXPECT_EQ(0, bv.cursor_screen_row());
+    EXPECT_EQ(0, bv.cursor_screen_column());
+    EXPECT_EQ(0, bv.cursor_virtual_column());
+}
+
+TEST(BufferViewTest, iterates_through_screen_lines_with_wrapping)
+{
+    std::shared_ptr<Buffer> b = buffer1();
+    std::shared_ptr<Buffer::Iterator> iterator = b->add_iterator();
+    BufferView bv(b, iterator, Cwd);
+    bv.resize(3, 10);
+    int times_called = 0;
+    int expected_row_offsets[] = {0, 1, 2, 4, 5, 6, 7};
+    bv.iter_lines([&times_called, &expected_row_offsets](int row_offset, const Buffer::Iterator & iterator) -> bool {
+            EXPECT_EQ(times_called, LineNumber(iterator));
+            EXPECT_EQ(expected_row_offsets[times_called], row_offset);
+            times_called++;
+            return true;
+            });
+    EXPECT_EQ(7, times_called);
+    EXPECT_EQ(0, bv.cursor_screen_row());
+    EXPECT_EQ(0, bv.cursor_screen_column());
+    EXPECT_EQ(0, bv.cursor_virtual_column());
+}
+
+TEST(BufferViewTest, fills_view_with_last_lines_of_buffer_when_cursor_warps_to_last_line)
+{
+    std::shared_ptr<Buffer> b = buffer1();
+    std::shared_ptr<Buffer::Iterator> iterator = b->add_iterator();
+    BufferView bv(b, iterator, Cwd);
+    while (iterator->go_next_line())
+    {
+    }
+    bv.resize(40, 3);
+    int times_called = 0;
+    int expected_row_offsets[] = {0, 1, 2};
+    bv.iter_lines([&times_called, &expected_row_offsets](int row_offset, const Buffer::Iterator & iterator) -> bool {
+            EXPECT_EQ(10 + times_called, LineNumber(iterator));
+            EXPECT_EQ(expected_row_offsets[times_called], row_offset);
+            times_called++;
+            return true;
+            });
+    EXPECT_EQ(3, times_called);
+    EXPECT_EQ(2, bv.cursor_screen_row());
+    EXPECT_EQ(0, bv.cursor_screen_column());
+    EXPECT_EQ(0, bv.cursor_virtual_column());
 }