1#[derive(Debug, Clone, PartialEq, Eq)]
2pub enum Start {
3 Direct(String),
4 Discover(String),
5}
6
7pub fn choose_start(cdp: Option<&str>, env: Option<&str>) -> Result<Start, String> {
8 if let Some(url) = nonempty(cdp) {
9 return classify(url);
10 }
11 if let Some(url) = nonempty(env) {
12 return classify(url);
13 }
14 Ok(Start::Discover(
15 "http://127.0.0.1:9222/json/version".to_string(),
16 ))
17}
18
19fn nonempty(value: Option<&str>) -> Option<&str> {
20 value.map(str::trim).filter(|s| !s.is_empty())
21}
22
23fn classify(url: &str) -> Result<Start, String> {
24 let lower = url.to_ascii_lowercase();
25 if lower.starts_with("ws://") || lower.starts_with("wss://") {
26 Ok(Start::Direct(url.to_string()))
27 } else if lower.starts_with("http://") || lower.starts_with("https://") {
28 Ok(Start::Discover(discovery_url(url)))
29 } else {
30 Err(format!(
31 "unsupported CDP URL \"{url}\" (expected ws://, wss://, http://, or https://)\n"
32 ))
33 }
34}
35
36pub fn discovery_url(http_url: &str) -> String {
37 if http_url.contains("/json/version") {
38 return http_url.to_string();
39 }
40 let trimmed = http_url.trim_end_matches('/');
41 format!("{trimmed}/json/version")
42}
43
44pub fn append_runtime(url: &str, runtime: Option<&str>) -> String {
45 let Some(runtime) = nonempty(runtime) else {
46 return url.to_string();
47 };
48 let enc = percent_encode(runtime);
49 if url.contains('?') {
50 format!("{url}&runtime={enc}")
51 } else {
52 format!("{url}?runtime={enc}")
53 }
54}
55
56pub fn format_http_error(status: u16, body: &[u8]) -> String {
57 let text = String::from_utf8_lossy(body);
58 let text = text.trim_end_matches('\0');
59 if text.is_empty() {
60 format!("HTTP {status}\n")
61 } else if text.ends_with('\n') {
62 format!("HTTP {status}\n{text}")
63 } else {
64 format!("HTTP {status}\n{text}\n")
65 }
66}
67
68pub fn websocket_url_from_version(body: &str) -> Result<String, String> {
69 let value: serde_json::Value =
70 serde_json::from_str(body).map_err(|err| format!("json/version: {err}\n"))?;
71 match value.get("webSocketDebuggerUrl").and_then(|v| v.as_str()) {
72 Some(url) if !url.is_empty() => Ok(url.to_string()),
73 _ => Err("json/version returned no webSocketDebuggerUrl\n".to_string()),
74 }
75}
76
77fn percent_encode(value: &str) -> String {
78 let mut out = String::new();
79 for byte in value.bytes() {
80 match byte {
81 b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'_' | b'.' | b'~' => {
82 out.push(byte as char);
83 }
84 _ => out.push_str(&format!("%{byte:02X}")),
85 }
86 }
87 out
88}
89
90#[cfg(test)]
91mod tests {
92 use super::*;
93
94 #[test]
95 fn flag_wins_over_env_and_discovery() {
96 let flag = "ws://127.0.0.1:9333/devtools/browser/from-flag";
97 let env = "ws://127.0.0.1:9222/devtools/browser/from-env";
98 assert_eq!(
99 choose_start(Some(flag), Some(env)).unwrap(),
100 Start::Direct(flag.to_string())
101 );
102 }
103
104 #[test]
105 fn env_url_is_opaque() {
106 let env = "ws://127.0.0.1:9222/devtools/browser/6f1c0a2e-1b4d-4e2a-9c77-0a1b2c3d4e5f";
107 assert_eq!(
108 choose_start(None, Some(env)).unwrap(),
109 Start::Direct(env.to_string())
110 );
111 }
112
113 #[test]
114 fn unset_uses_json_version_discovery() {
115 assert_eq!(
116 choose_start(None, None).unwrap(),
117 Start::Discover("http://127.0.0.1:9222/json/version".to_string())
118 );
119 }
120
121 #[test]
122 fn http_flag_is_discovery() {
123 assert_eq!(
124 choose_start(Some("http://127.0.0.1:9444"), None).unwrap(),
125 Start::Discover("http://127.0.0.1:9444/json/version".to_string())
126 );
127 }
128
129 #[test]
130 fn does_not_invent_a_debugger_path() {
131 let start = choose_start(None, None).unwrap();
132 let text = format!("{start:?}");
133 assert!(!text.contains("cdp.slicc.internal"));
134 assert!(!text.contains("cdp.kernel.localhost"));
135 assert!(!text.contains("/devtools/browser"));
136 }
137
138 #[test]
139 fn runtime_query_appends() {
140 assert_eq!(
141 append_runtime("ws://127.0.0.1:9222/devtools/browser/abc", Some("follower")),
142 "ws://127.0.0.1:9222/devtools/browser/abc?runtime=follower"
143 );
144 assert_eq!(
145 append_runtime("ws://127.0.0.1:9222/devtools/browser/abc?x=1", Some("a b")),
146 "ws://127.0.0.1:9222/devtools/browser/abc?x=1&runtime=a%20b"
147 );
148 assert_eq!(
149 append_runtime("ws://127.0.0.1:9222/p", None),
150 "ws://127.0.0.1:9222/p"
151 );
152 }
153
154 #[test]
155 fn http_error_prints_status_and_body() {
156 assert_eq!(format_http_error(503, b"no host"), "HTTP 503\nno host\n");
157 assert_eq!(format_http_error(404, b""), "HTTP 404\n");
158 assert_eq!(format_http_error(404, b"missing\n"), "HTTP 404\nmissing\n");
159 }
160
161 #[test]
162 fn version_body_uses_returned_socket_only() {
163 let body = r#"{"webSocketDebuggerUrl":"ws://127.0.0.1:9222/devtools/browser/uuid"}"#;
164 assert_eq!(
165 websocket_url_from_version(body).unwrap(),
166 "ws://127.0.0.1:9222/devtools/browser/uuid"
167 );
168 assert!(websocket_url_from_version("{}").is_err());
169 }
170}