Add support for HTTP HEAD requests

This update introduces parsing for HTTP HEAD requests. A new test case `test_request_parse_head` ensures the functionality is verified. The HTTP method enumeration is adjusted to include HEAD.

src/tiny_http/tiny_http_server_lib.c

@@ -184,6 +184,10 @@ enum parse_http_request_status parse_http_request_line_from_packet(
         *ptr += 5; // "POST" - 5
         start_uri = 5;
         request->method = POST;
+    } else if (strncmp((char *) http_packet, "HEAD", 4) == 0) {
+        *ptr += 5; // "HEAD" - 5
+        start_uri = 5;
+        request->method = HEAD;
     } else {
         fprintf(stderr, "right now, only HTTP GET and POST verbs are supported");
         fflush(stderr);

src/tiny_http/tiny_http_server_lib.h

@@ -17,7 +17,8 @@ typedef enum http_version {
 
 typedef enum http_method {
     GET = 1,
-    POST = 2,
+    HEAD = 2,
+    POST = 3,
 } http_method;
 
 typedef struct http_header {

test/assert_tiny_http_server_lib.c

@@ -110,10 +110,34 @@ void test_request_post_root_curl_with_wide_chars(void) {
     destroy_http_request(http_req);
 }
 
+void test_request_parse_head(void) {
+    const uint8_t request[] = "HEAD /test HTTP/1.0\r\n"
+            "Host: localhost:8085\r\n"
+            "User-Agent: custom-agent/1.0\r\n"
+            "Accept: */*\r\n"
+            "\r\n";
+    http_request *http_req = parse_http_request(request, strlen((char *) request));
+    assert(http_req != nullptr);
+    assert(http_req->method == HEAD);
+    assert(http_req->version == HTTP_1_0);
+    assert(strncmp(http_req->url, "/test", 255) == 0);
+    assert(http_req->headers_cnt == 3);
+    assert(strncmp(http_req->headers[0]->name, "Host", 255) == 0);
+    assert(strncmp(http_req->headers[0]->value, "localhost:8085", 255) == 0);
+    assert(strncmp(http_req->headers[1]->name, "User-Agent", 255) == 0);
+    assert(strncmp(http_req->headers[1]->value, "custom-agent/1.0", 255) == 0);
+    assert(strncmp(http_req->headers[2]->name, "Accept", 255) == 0);
+    assert(strncmp(http_req->headers[2]->value, "*/*", 255) == 0);
+    assert(http_req->body == nullptr);
+    assert(http_req->body_len == 0);
+    destroy_http_request(http_req);
+}
+
 int main() {
     test_request_parse_get_root_curl();
     test_request_post_root_curl();
     test_request_post_root_curl_with_wide_chars();
+    test_request_parse_head();
 
     return EXIT_SUCCESS;
 }