Added unit tests for String data type and updated CI

tests/test_string.c

@@ -0,0 +1,153 @@
+/*
+ * Unit tests for String data type
+*/
+
+#define TEST(NAME) do { \
+    printf("Running test_%s...", #NAME); \
+    test_##NAME(); \
+    printf(" PASSED\n"); \
+} while(0)
+
+#include <stdio.h>
+#include <assert.h>
+#include <string.h>
+
+#include "../src/string.h"
+
+// Test string creation
+void test_string_new(void) {
+    string_result_t res = string_new("hello");
+
+    assert(res.status == STRING_OK);
+    assert(res.value.string != NULL);
+    assert(strcmp(res.value.string->data, "hello") == 0);
+    assert(string_len(res.value.string) == 5);
+    assert(res.value.string->byte_size == 5);
+
+    string_destroy(res.value.string);
+}
+
+// Test empty string
+void test_string_new_empty(void) {
+    string_result_t res = string_new("");
+
+    assert(res.status == STRING_OK);
+    assert(string_len(res.value.string) == 0);
+    assert(res.value.string->byte_size == 0);
+    assert(res.value.string->data[0] == '\0');
+
+    string_destroy(res.value.string);
+}
+
+// Test string concatenation
+void test_string_concat(void) {
+    string_t *str1 = string_new("Foo").value.string;
+    string_t *str2 = string_new(" Bar").value.string;
+
+    string_result_t res = string_concat(str1, str2);
+    assert(res.status == STRING_OK);
+    assert(strcmp(res.value.string->data, "Foo Bar") == 0);
+    assert(string_len(res.value.string) == 7);
+
+    string_destroy(str1);
+    string_destroy(str2);
+    string_destroy(res.value.string);
+}
+
+// Test case-insensitive and sensitive comparison
+void test_string_eq(void) {
+    string_t *str1 = string_new("Foo").value.string;
+    string_t *str2 = string_new("foo").value.string;
+
+    // Case sensitive comparison should be false
+    assert(string_eq(str1, str2, true).value.is_equ == false);
+    // Case insensitive comparison should be true
+    assert(string_eq(str1, str2, false).value.is_equ == true);
+
+    string_destroy(str1);
+    string_destroy(str2);
+}
+
+// Test string reverse using UTF-8 symbols
+void test_string_reverse_utf8(void) {
+    string_t *str = string_new("A🌍Z").value.string;
+
+    string_result_t res = string_reverse(str);
+    
+    assert(res.status == STRING_OK);
+    assert(string_len(res.value.string) == 3);
+    assert(strcmp(res.value.string->data, "Z🌍A") == 0);
+    assert(string_len(res.value.string) == 3);
+
+    string_destroy(str);
+    string_destroy(res.value.string);
+}
+
+// Test mutation of UTF-8 symbol
+void test_string_set_at(void) {
+    string_t *str = string_new("ABC").value.string;
+
+    // Replace 'B' with emoji
+    string_result_t res = string_set_at(str, 1, "😆");
+    assert(res.status == STRING_OK);
+    assert(strcmp(str->data, "A😆C") == 0);
+    assert(string_len(str) == 3);
+    assert(str->byte_size == 6); // that is: A (1B) + emoji (4B) + C (1B)
+
+    string_destroy(str);
+}
+
+// Test mutation with overflow
+void test_string_set_at_overflow(void) {
+    string_t *str = string_new("ABC").value.string;
+
+    string_result_t res = string_set_at(str, 10, "a");
+    assert(res.status == STRING_ERR_OVERFLOW);
+
+    string_destroy(str);
+}
+
+// Test whitespace trimming
+void test_string_trim(void) {
+    string_t *str = string_new("   \t   Foo Bar \n    ").value.string;
+
+    string_result_t res = string_trim(str);
+    assert(res.status == STRING_OK);
+    assert(strcmp(res.value.string->data, "Foo Bar") == 0);
+
+    string_destroy(str);
+    string_destroy(res.value.string);
+}
+
+// Test string splitting into an array
+void test_string_split(void) {
+    string_t *str = string_new("Red,Green,Blue").value.string;
+
+    string_result_t res = string_split(str, ",");
+    assert(res.status == STRING_OK);
+    assert(res.value.split.count == 3);
+
+    assert(strcmp(res.value.split.strings[0]->data, "Red") == 0);
+    assert(strcmp(res.value.split.strings[1]->data, "Green") == 0);
+    assert(strcmp(res.value.split.strings[2]->data, "Blue") == 0);
+
+    string_split_destroy(res.value.split.strings, res.value.split.count);
+    string_destroy(str);
+}
+
+int main(void) {
+    printf("=== Running Vector unit tests ===\n\n");
+
+    TEST(string_new);
+    TEST(string_new_empty);
+    TEST(string_concat);
+    TEST(string_eq);
+    TEST(string_reverse_utf8);
+    TEST(string_set_at);
+    TEST(string_set_at_overflow);
+    TEST(string_trim);
+    TEST(string_split);
+
+    printf("\n=== All tests passed! ===\n");
+    return 0;
+}