refactor: string extend method

string/mystring.c

@@ -138,7 +138,25 @@ int mcl_string_append(mcl_string_s *string, const char *text) {
 }
 
 int mcl_string_extend(mcl_string_s *destination, mcl_string_s *source) {
-	/* TODO */
+	if (destination == NULL || source == NULL) {
+		return -1;
+	}
+
+	size_t need = destination->size + source->size;
+	if (need > destination->capacity) {
+		/* Reallocate destination data buffer */
+		destination->capacity = next_power_two(need);
+		char *tmp = realloc(destination->data, destination->capacity);
+		if (tmp == NULL) {
+			return -1;
+		}
+		destination->data = tmp;
+	}
+
+	/* Copy memory from source data buffer */
+	memcpy(destination->data + destination->size, source->data, source->size);
+	destination->size = need;
+	destination->data[destination->size] = '\0';
 
 	return 0;
 }

string/mystring.h

@@ -105,4 +105,15 @@ void mcl_string_toupper(mcl_string_s *string);
  */
 void mcl_string_tolower(mcl_string_s *string);
 
+/**
+ * @brief Find a substring inside a string.
+ *
+ * @param string String where to search.
+ * @param substring Substring to search.
+ * @return Index of the first occurrence, -1 on failure.
+ *
+ * @note TODO
+ */
+int mcl_string_find(mcl_string_s *string, const char *substring);
+
 #endif /* MYCLIB_STRING_H */

test/string/str2.c

@@ -22,6 +22,13 @@ void test_str2(void) {
 	assert(strcmp(mcl_string_cstr(s1), "") == 0);
 	assert(strcmp(mcl_string_cstr(s2), "HELLO, WORLD!") == 0);
 
+	/* Extend a string */
+	mcl_string_s *extend_me = mcl_string_new("This string is suuuuuuuuuuuuuuuuuuuuuper extended!", 0);
+	mcl_string_extend(s1, extend_me);
+	assert(mcl_string_length(s1) == 50);
+	assert(mcl_string_capacity(s1) == 64);
+
 	mcl_string_free(s1);
 	mcl_string_free(s2);
+	mcl_string_free(extend_me);
 }

test/test.c

@@ -5,6 +5,11 @@
 #include <assert.h>
 #include <stdio.h>
 
+void test_hm1();
+void test_q1();
+void test_str1();
+void test_str2();
+
 int main(void) {
 	puts("==== [Running Hashmap tests] ====");
 	test_hm1();