From 6a5cbab93c381d36e679b17cf5d7c126dc2fe5ba Mon Sep 17 00:00:00 2001
From: Michael Kohl <me@citizen428.net>
Date: Fri, 6 Feb 2026 11:09:35 +0700
Subject: [PATCH] Add test for herb_read_file

Document that the function exits when the filename is invalid.
---
 Makefile         | 2 +-
 test/c/test_io.c | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 6a44f0758..4638055ed 100644
--- a/Makefile
+++ b/Makefile
@@ -95,7 +95,7 @@ $(static_lib_name): $(objects)
 src/%.o: src/%.c templates
 	$(cc) -c $(flags) -fPIC $< -o $@
 
-test/%.o: test/%.c templates
+test/%.o: test/%.c templates prism
 	$(cc) -c $(test_cflags) $(test_flags) $(prism_flags) $< -o $@
 
 .PHONY: test
diff --git a/test/c/test_io.c b/test/c/test_io.c
index b49cab89f..52dc0ee66 100644
--- a/test/c/test_io.c
+++ b/test/c/test_io.c
@@ -11,6 +11,12 @@ void create_test_file(const char* filename, const char* content) {
   fclose(fp);
 }
 
+// Test that reading a non-existent file correctly exits
+// Note: Check verifies the exit code via tcase_add_exit_test, so no assertions.
+TEST(test_herb_read_file_nonexistent_exits)
+  herb_read_file("non_existent_file.txt");
+END
+
 // Test reading from a file
 TEST(test_herb_read_file)
   const char* filename = "test_herb_read_file.txt";
@@ -31,6 +37,7 @@ TCase* io_tests(void) {
   TCase* io = tcase_create("IO");
 
   tcase_add_test(io, test_herb_read_file);
+  tcase_add_exit_test(io, test_herb_read_file_nonexistent_exits, 1);
 
   return io;
 }