picohttpparser: add tests for the Request methods (#20906)

vlib/picohttpparser/request_test.v

@@ -0,0 +1,63 @@
+module picohttpparser
+
+pub fn test_parses_a_simple_get_request() {
+	mut req := Request{}
+	parsed := req.parse_request('GET / HTTP/1.1\r\nHost: example.com\r\n\r\n') or {
+		assert false, 'error while parse request: ${err}'
+		0
+	}
+
+	assert parsed == 37
+	assert req.method == 'GET'
+	assert req.path == '/'
+	assert req.headers[0].name == 'Host'
+	assert req.headers[0].value == 'example.com'
+}
+
+pub fn test_parses_multiple_headers() {
+	mut req := Request{}
+	parsed := req.parse_request('GET /foo?bar=baz HTTP/1.1\r\nHeader1: value1\r\nHeader2: value2\r\n\r\n') or {
+		assert false, 'error while parse request: ${err}'
+		0
+	}
+	assert parsed == 63
+	assert req.headers[1].name == 'Header2'
+	assert req.headers[1].value == 'value2'
+}
+
+pub fn test_parses_requests_with_bodies() {
+	mut req := Request{}
+	parsed := req.parse_request('POST /data HTTP/1.1\r\nContent-Length: 10\r\n\r\nsomedata') or {
+		assert false, 'error while parse request: ${err}'
+		0
+	}
+	assert parsed == 43
+	assert req.body == 'somedata'
+}
+
+pub fn test_handles_empty_requests() {
+	mut req := Request{}
+	parsed := req.parse_request('') or {
+		assert false, 'error while parse request: ${err}'
+		0
+	}
+	assert parsed == -2
+}
+
+pub fn test_handles_incomplete_requests() {
+	mut req := Request{}
+	partial_parsed := req.parse_request('GET /partial') or {
+		assert false, 'error while parse request: ${err}'
+		0
+	}
+	assert partial_parsed == -2
+	assert req.prev_len == 0
+
+	remaining_parsed := req.parse_request(' HTTP/1.1\r\n\r\n') or {
+		assert err.msg == 'error parsing request: invalid character "13"'
+		0
+	}
+	assert remaining_parsed == 0
+	assert req.method == ''
+	assert req.path == ''
+}