From b53e84b08d98ac03ffa7aa4500db9701c7b0b88f Mon Sep 17 00:00:00 2001
From: iWas-Coder <wasymatieh01@gmail.com>
Date: Sat, 20 Jul 2024 20:59:39 +0200
Subject: [PATCH] Output git-style diff between original test code and
 generated one

---
 .gitignore    | 1 +
 ai/testgen.cc | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/.gitignore b/.gitignore
index 9cf433c..a05c0f3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@ ai/build/
 *.xml
 test/carbon
 ai/testgen
+ai/*.diff
diff --git a/ai/testgen.cc b/ai/testgen.cc
index c9105b2..87a6875 100644
--- a/ai/testgen.cc
+++ b/ai/testgen.cc
@@ -171,4 +171,12 @@ int main(int argc, char **argv) {
   std::cout << "\n\n2. It builds?:" << std::endl;
   if (it_builds(buf)) std::cout << "Yes. Hurray!" << std::endl;
   else std::cout << "No. Maybe next time..." << std::endl;
+
+  std::ofstream ofs { "tmp.cc" };
+  if (not ofs) throw std::runtime_error { "unable to open/create file for writing (`./tmp.cc`)" };
+  ofs << buf.str();
+  ofs.close();
+  [[maybe_unused]] int result { std::system(("diff -u " + test_file + " tmp.cc > testgen.diff").c_str()) };
+  std::remove("tmp.cc");
+  std::cout << "\nOutput from BSD Carbon AI written to: `testgen.diff`" << std::endl;
 }