From 65be7c3a6f01feb265d9c049f770c2b5a0f4a719 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Mon, 26 Mar 2018 10:34:19 -0400
Subject: [PATCH] Add Buffer::n_lines()

---
 src/core/Buffer.cc      | 11 +++++++++++
 src/core/Buffer.h       |  1 +
 test/src/test_Buffer.cc |  2 ++
 3 files changed, 14 insertions(+)

diff --git a/src/core/Buffer.cc b/src/core/Buffer.cc
index 3896bb1..9cea42d 100644
--- a/src/core/Buffer.cc
+++ b/src/core/Buffer.cc
@@ -502,3 +502,14 @@ void Buffer::set_filename(const std::string & filename)
 {
     m_filename = std::make_shared<std::string>(filename);
 }
+
+size_t Buffer::n_lines() const
+{
+    auto it = end();
+    it.go_back();
+    if (it.valid())
+    {
+        return it.line() + 1u;
+    }
+    return 0u;
+}
diff --git a/src/core/Buffer.h b/src/core/Buffer.h
index 2a38533..d68c366 100644
--- a/src/core/Buffer.h
+++ b/src/core/Buffer.h
@@ -192,6 +192,7 @@ public:
     void pop_operation();
     void undo();
     void redo();
+    size_t n_lines() const;
 
 #ifndef ENABLE_TESTING
 protected:
diff --git a/test/src/test_Buffer.cc b/test/src/test_Buffer.cc
index 50a5968..a9ed2b4 100644
--- a/test/src/test_Buffer.cc
+++ b/test/src/test_Buffer.cc
@@ -33,11 +33,13 @@ TEST(BufferTest, writes_an_empty_file_for_an_empty_buffer)
     Buffer b;
     ASSERT_TRUE(b.write_to_file("test/tmp/f"));
     TestSupport::compare_files("test/files/empty.txt", "test/tmp/f");
+    ASSERT_EQ(0u, b.n_lines());
 }
 
 TEST(BufferTest, allows_navigating_using_iterators)
 {
     Buffer b("test/files/line_endings/lf_format.txt");
+    ASSERT_EQ(2u, b.n_lines());
     auto iterator = b.add_cursor();
 
     EXPECT_EQ(0u, iterator->line());