feat: Update version to 0.4.0, add test command, and improve documentation for testing functionality

src/config.rs

@@ -7,9 +7,81 @@ int main(void) {
 }
 "#;
 
+pub const FILE_DCR_TEST_H: &str = r#"#pragma once
+#include <stdio.h>
+#include <string.h>
+
+#define DCR_TEST_PASS 0
+#define DCR_TEST_FAIL 1
+#define DCR_TEST_SKIP 2
+
+#define EXPECT(expr) \
+    do { \
+        if (!(expr)) { \
+            fprintf(stderr, "assert failed: %s (%s:%d)\n", #expr, __FILE__, __LINE__); \
+            return DCR_TEST_FAIL; \
+        } \
+    } while (0)
+
+#define SKIP(reason) \
+    do { \
+        (void)(reason); \
+        return DCR_TEST_SKIP; \
+    } while (0)
+
+#define TEST(name) static int name(void)
+#define TEST_CASE(name) {#name, name}
+
+typedef int (*test_fn_t)(void);
+
+typedef struct {
+    const char *name;
+    test_fn_t fn;
+} test_case_t;
+
+static inline int dcr_test_raw_mode(int argc, char **argv) {
+    return argc > 1 && strcmp(argv[1], "--dcr-raw") == 0;
+}
+
+static inline void dcr_test_print_result(const char *name, int rc, int raw_mode) {
+    const char *tag = (rc == DCR_TEST_PASS) ? "PASS" : (rc == DCR_TEST_SKIP) ? "SKIP" : "FAIL";
+    if (raw_mode) {
+        printf("%s\t%s\n", tag, name);
+    } else {
+        printf("[%s] %s\n", tag, name);
+    }
+}
+"#;
+
+pub const FILE_TEST_C: &str = r#"#include "dcr_test.h"
+
+TEST(test_example) {
+    EXPECT(1 + 1 == 2);
+    return DCR_TEST_PASS;
+}
+
+static test_case_t CASES[] = {
+    TEST_CASE(test_example),
+};
+
+int main(int argc, char **argv) {
+    int raw = dcr_test_raw_mode(argc, argv);
+    int rc = 0;
+    int count = (int)(sizeof(CASES) / sizeof(CASES[0]));
+    for (int i = 0; i < count; ++i) {
+        int status = CASES[i].fn();
+        dcr_test_print_result(CASES[i].name, status, raw);
+        if (status == DCR_TEST_FAIL) {
+            rc = 1;
+        }
+    }
+    return rc;
+}
+"#;
+
 pub fn flags(profile: &str) -> Option<&'static [&'static str]> {
     match profile {
-        "release" => Some(&["-O3", "-DNDEBUG", "-march=native"]),
+        "release" => Some(&["-O3", "-DNDEBUG"]),
         "debug" => Some(&[
             "-O0",
             "-g",