feat(tests): mini testsuite for token creation

tests/unit/lexer/lexer_tests.c

@@ -0,0 +1,61 @@
+#include <criterion/criterion.h>
+#include <criterion/new/assert.h>
+#include <criterion/redirect.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "lexer/lexer.h"
+
+TestSuite(token_creation);
+
+Test(token_creation, basic)
+{
+    char *input = "Hello World";
+
+    char *actual = new_token(input, 5);
+    char *expected = "Hello";
+    cr_expect(eq(str, actual, expected));
+    free(actual);
+}
+
+Test(token_creation, nul)
+{
+    char *input = NULL;
+
+    char *actual = new_token(input, 5);
+    char *expected = NULL;
+    cr_expect(eq(str, actual, expected));
+    free(actual);
+}
+
+Test(token_creation, too_large)
+{
+    char *input = "Hel";
+
+    char *actual = new_token(input, 5);
+    char *expected = NULL;
+    cr_expect(eq(str, actual, expected));
+    free(actual);
+}
+
+Test(token_creation, empty)
+{
+    char *input = "";
+
+    char *actual = new_token(input, 5);
+    char *expected = NULL;
+    cr_expect(eq(str, actual, expected));
+    free(actual);
+}
+
+Test(token_creation, basic_long)
+{
+    char *input = "Hello World! This project is a mini shell, I love BIG G.";
+
+    char *actual = new_token(input, 42);
+    char *expected = calloc(42 + 1, sizeof(char));
+    strncpy(input, expected, 42);
+    cr_expect(eq(str, actual, expected));
+    free(actual);
+    free(expected);
+}