From 0bcfdedbb41f92381f562efb2d2d28bd96f1be56 Mon Sep 17 00:00:00 2001
From: Yuri Smirnov <tycoooon@gmail.com>
Date: Thu, 12 Dec 2024 13:58:11 +0300
Subject: [PATCH] preserve newlines

---
 lib/lamian/log_device.rb       |  3 ++-
 spec/lamian/log_device_spec.rb | 21 +++++++++++++++------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/lib/lamian/log_device.rb b/lib/lamian/log_device.rb
index b7fa305..77bc32f 100644
--- a/lib/lamian/log_device.rb
+++ b/lib/lamian/log_device.rb
@@ -26,7 +26,8 @@ def string # :nodoc:
     def truncate(msg)
       return msg unless msg.size > max_log_length
 
-      suffix = "..."
+      suffix = +"..."
+      suffix << "\n" if msg.end_with?("\n")
       msg = msg[0, max_log_length - suffix.size]
 
       "#{msg}#{suffix}"
diff --git a/spec/lamian/log_device_spec.rb b/spec/lamian/log_device_spec.rb
index fce8298..5ba7de8 100644
--- a/spec/lamian/log_device_spec.rb
+++ b/spec/lamian/log_device_spec.rb
@@ -4,9 +4,9 @@
   subject(:logdev) { described_class.new(max_log_lines: 5, max_log_length: 20) }
 
   it "saves log" do
-    logdev.write("Hello ")
-    logdev.write("world!")
-    expect(logdev.string).to eq("Hello world!")
+    logdev.write("Hello\n")
+    logdev.write("world!\n")
+    expect(logdev.string).to eq("Hello\nworld!\n")
   end
 
   it "only stores 5 latest log lines" do
@@ -14,8 +14,17 @@
     expect(logdev.string).to eq("45678")
   end
 
-  it "truncates long lines" do
-    logdev.write("Hello world, this is me!")
-    expect(logdev.string).to eq("Hello world, this...")
+  context "long log lines" do
+    it "truncates log" do
+      logdev.write("Hello world, this is me!")
+      expect(logdev.string).to eq("Hello world, this...")
+    end
+
+    context "line with newline in the end" do
+      it "truncates log and adds newline" do
+        logdev.write("Hello world, this is me!\n")
+        expect(logdev.string).to eq("Hello world, thi...\n")
+      end
+    end
   end
 end