1 files changed, 70 insertions, 0 deletions
diff --git a/tests/test_csv.c b/tests/test_csv.c
new file mode 100644
index 0000000..cbf206b
--- /dev/null
+++ b/tests/test_csv.c
@@ -0,0 +1,70 @@
+#include "vendor/unity/src/unity.h"
+
+#include "../src/c/fastforge_csv.h"
+
+#include <string.h>
+
+void test_csv_append_text_plain_and_escaped_values(void) {
+  char buffer[128];
+  size_t offset;
+
+  buffer[0] = '\0';
+  offset = csv_append_text(buffer, sizeof(buffer), 0, "plain");
+  TEST_ASSERT_EQUAL_size_t(strlen("plain"), offset);
+  TEST_ASSERT_EQUAL_STRING("plain", buffer);
+
+  buffer[0] = '\0';
+  offset = csv_append_text(buffer, sizeof(buffer), 0, "alpha,beta");
+  TEST_ASSERT_EQUAL_STRING("\"alpha,beta\"", buffer);
+  TEST_ASSERT_EQUAL_size_t(strlen("\"alpha,beta\""), offset);
+
+  buffer[0] = '\0';
+  offset = csv_append_text(buffer, sizeof(buffer), 0, "say \"hi\"");
+  TEST_ASSERT_EQUAL_STRING("\"say \"\"hi\"\"\"", buffer);
+  TEST_ASSERT_EQUAL_size_t(strlen("\"say \"\"hi\"\"\""), offset);
+
+  strcpy(buffer, "seed");
+  offset = csv_append_text(buffer, sizeof(buffer), 4, NULL);
+  TEST_ASSERT_EQUAL_size_t(4, offset);
+  TEST_ASSERT_EQUAL_STRING("seed", buffer);
+}
+
+void test_csv_append_int_appends_number_text(void) {
+  char buffer[64];
+  size_t offset;
+
+  buffer[0] = '\0';
+  offset = csv_append_int(buffer, sizeof(buffer), 0, -42);
+  TEST_ASSERT_EQUAL_size_t(strlen("-42"), offset);
+  TEST_ASSERT_EQUAL_STRING("-42", buffer);
+}
+
+void test_format_history_csv_header_and_row_with_escaping(void) {
+  FastEntry entry;
+  char row[256];
+  char header[128];
+
+  memset(&entry, 0, sizeof(entry));
+  entry.start_time = 100;
+  entry.end_time = 200;
+  entry.target_minutes = 960;
+  entry.max_stage_reached = 2;
+  snprintf(entry.note, sizeof(entry.note), "meal, \"keto\"");
+
+  format_history_csv_header(header, sizeof(header));
+  TEST_ASSERT_EQUAL_STRING(
+      "start_time,end_time,target_minutes,note,max_stage_reached",
+      header);
+
+  format_history_csv_row(&entry, row, sizeof(row));
+  TEST_ASSERT_EQUAL_STRING("100,200,960,\"meal, \"\"keto\"\"\",2", row);
+}
+
+void test_format_history_csv_row_null_entry_returns_empty(void) {
+  char row[32];
+  strcpy(row, "not-empty");
+
+  format_history_csv_row(NULL, row, sizeof(row));
+
+  TEST_ASSERT_EQUAL_STRING("", row);
+}