From f528aedc8573ade58d09b0dd7ecf8d54ec53c57f Mon Sep 17 00:00:00 2001
From: Shannon Booth <shannon.ml.booth@gmail.com>
Date: Tue, 27 Jun 2023 20:59:01 +1200
Subject: [PATCH] LibDiff: Add Diff::write_unified_header

This is used to write a unified patch header.
---
 Userland/Libraries/LibDiff/Format.cpp | 8 ++++++++
 Userland/Libraries/LibDiff/Format.h   | 2 ++
 2 files changed, 10 insertions(+)

diff --git a/Userland/Libraries/LibDiff/Format.cpp b/Userland/Libraries/LibDiff/Format.cpp
index 996b56079b..7951a92d11 100644
--- a/Userland/Libraries/LibDiff/Format.cpp
+++ b/Userland/Libraries/LibDiff/Format.cpp
@@ -24,6 +24,14 @@ DeprecatedString generate_only_additions(StringView text)
     return builder.to_deprecated_string();
 }
 
+ErrorOr<void> write_unified_header(StringView old_path, StringView new_path, Stream& stream)
+{
+    TRY(stream.write_formatted("--- {}\n", old_path));
+    TRY(stream.write_formatted("+++ {}\n", new_path));
+
+    return {};
+}
+
 ErrorOr<void> write_unified(Hunk const& hunk, Stream& stream, ColorOutput color_output)
 {
     TRY(stream.write_formatted("{}\n", hunk.location));
diff --git a/Userland/Libraries/LibDiff/Format.h b/Userland/Libraries/LibDiff/Format.h
index 0ae15ed258..303c804c24 100644
--- a/Userland/Libraries/LibDiff/Format.h
+++ b/Userland/Libraries/LibDiff/Format.h
@@ -21,6 +21,8 @@ enum class ColorOutput {
 };
 
 ErrorOr<void> write_unified(Hunk const& hunk, Stream& stream, ColorOutput color_output = ColorOutput::No);
+ErrorOr<void> write_unified_header(StringView old_path, StringView new_path, Stream& stream);
+
 ErrorOr<void> write_normal(Hunk const& hunk, Stream& stream, ColorOutput color_output = ColorOutput::No);
 
 }