From ff900a00d869e44a1930fad0cbd87b292cdac3ca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Imanol=20Guti=C3=A9rrez?= <imanol@imanol.org>
Date: Sat, 12 Sep 2026 16:28:35 +0300
Subject: [PATCH 1/2] Add a newline char at EOF on C and C++ headers

---
 graphify/extractors/engine.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/graphify/extractors/engine.py b/graphify/extractors/engine.py
index 16109a7770..aeec2574aa 100644
--- a/graphify/extractors/engine.py
+++ b/graphify/extractors/engine.py
@@ -3177,6 +3177,11 @@ def _extract_generic(
     try:
         parser = Parser(language)
         source = path.read_bytes() if source_override is None else source_override
+        # In C and C++, if the .h file does not end with a newline '\n' an error
+        # is throwed even if the file is valid. In order to avoid this, a new line
+        # char is added only if the original file does not end with it.
+        if source and not source.endswith(b"\n"):
+            source = source + b"\n"
         tree = parser.parse(source)
         root = tree.root_node
     except Exception as e:

From 543c171ec117d11347f64bd70e0fa7168b10c785 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Imanol=20Guti=C3=A9rrez?= <imanol@imanol.org>
Date: Sat, 12 Sep 2026 16:28:53 +0300
Subject: [PATCH 2/2] Add tests for newline char at EOF fix

---
 ...est_trailing_newline_not_a_syntax_error.py | 70 +++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 tests/test_trailing_newline_not_a_syntax_error.py

diff --git a/tests/test_trailing_newline_not_a_syntax_error.py b/tests/test_trailing_newline_not_a_syntax_error.py
new file mode 100644
index 0000000000..3140bcda7b
--- /dev/null
+++ b/tests/test_trailing_newline_not_a_syntax_error.py
@@ -0,0 +1,70 @@
+"""Tests for files that do not end with a newline.
+
+In C and C++, if the .h file does not end with a newline '\n' an error
+is throwed even if the file is valid. In order to avoid this, a new line
+char is added only if the original file does not end with it.
+
+In this test we will make sure this works.
+"""
+
+from graphify.extract import extract, extract_c, extract_cpp
+
+TEST_HEADER_1 = """\
+#define A 8
+#define AA 3"""
+
+TEST_HEADER_2 = """\
+#define A 8
+
+int foo(int bar) { return bar; }
+
+int foo2(void) { return 0; }
+
+#define AA 1"""
+
+TEST_HEADER_3 = """\
+#pragma once
+
+#define A 4"""
+
+
+def write(path, text):
+    path.write_bytes(text.encode("utf-8"))
+    return path
+
+
+def stderr_of(tmp_path, path, capsys):
+    extract([path], root=tmp_path)
+    return capsys.readouterr().err
+
+
+def test_c_header_without_newline(tmp_path, capsys):
+    path = write(tmp_path / "test_header.h", TEST_HEADER_1)
+    assert "partially extracted" not in stderr_of(tmp_path, path, capsys)
+
+
+def test_cpp_header_without_newline(tmp_path, capsys):
+    path = write(tmp_path / "test_header.hpp", TEST_HEADER_3)
+    assert "partially extracted" not in stderr_of(tmp_path, path, capsys)
+
+
+def test_c_header_with_newline(tmp_path, capsys):
+    path = write(tmp_path / "test_header.h", TEST_HEADER_1 + "\n")
+    assert "partially extracted" not in stderr_of(tmp_path, path, capsys)
+
+
+def test_no_parse_errors(tmp_path):
+    assert extract_c(write(tmp_path / "test_header.h", TEST_HEADER_1)).get("parse_errors") is None
+    assert extract_cpp(write(tmp_path / "test_header.hpp", TEST_HEADER_3)).get("parse_errors") is None
+
+
+def test_functions_are_still_found(tmp_path):
+    path = write(tmp_path / "test_header.h", TEST_HEADER_2)
+    labels = [node["label"] for node in extract_c(path)["nodes"]]
+    assert "foo()" in labels
+    assert "foo2()" in labels
+
+
+def test_empty_file(tmp_path):
+    path = write(tmp_path / "test_header.c", "")
+    assert extract_c(path).get("parse_errors") is None