browser_control/cli/
eval.rs

1//! `browser-control eval` — evaluate a JS expression in the active page.
2
3use anyhow::Result;
4use serde_json::Value;
5
6use crate::cli::mcp::resolve_browser;
7use crate::session::PageSession;
8
9pub async fn run(
10    browser: Option<String>,
11    expression: String,
12    target: Option<String>,
13    json: bool,
14    await_promise: bool,
15) -> Result<()> {
16    let resolved = resolve_browser(browser).await?;
17    let session = PageSession::attach(&resolved.endpoint, resolved.engine, target.as_deref()).await?;
18    let value = session.evaluate(&expression, await_promise).await;
19    session.close().await;
20    let value = value?;
21    println!("{}", format_output(&value, json));
22    Ok(())
23}
24
25fn format_output(v: &Value, json: bool) -> String {
26    if json {
27        serde_json::to_string_pretty(v).unwrap_or_else(|_| v.to_string())
28    } else if let Some(s) = v.as_str() {
29        s.to_string()
30    } else {
31        serde_json::to_string(v).unwrap_or_else(|_| v.to_string())
32    }
33}
34
35#[cfg(test)]
36mod tests {
37    use super::*;
38    use serde_json::json;
39
40    #[test]
41    fn eval_returns_string_unquoted_in_text_mode() {
42        let v = json!("hello");
43        assert_eq!(format_output(&v, false), "hello");
44    }
45
46    #[test]
47    fn eval_returns_number_as_json() {
48        let v = json!(42);
49        assert_eq!(format_output(&v, false), "42");
50    }
51
52    #[test]
53    fn eval_returns_json_envelope_when_json_flag() {
54        let v = json!({"a": 1});
55        let out = format_output(&v, true);
56        let parsed: Value = serde_json::from_str(&out).expect("valid JSON");
57        assert_eq!(parsed, v);
58        assert!(out.contains("\"a\""));
59    }
60
61    #[test]
62    fn eval_null_text_mode() {
63        let v = json!(null);
64        assert_eq!(format_output(&v, false), "null");
65    }
66
67    #[test]
68    fn eval_bool_text_mode() {
69        assert_eq!(format_output(&json!(true), false), "true");
70    }
71
72    // Mock CDP round-trip test mirroring src/session/attach.rs tests.
73    use crate::detect::Engine;
74    use crate::session::PageSession;
75    use futures_util::{SinkExt, StreamExt};
76    use tokio_tungstenite::tungstenite::Message;
77
78    async fn spawn_cdp_mock(targets: Vec<Value>, eval_value: Value) -> String {
79        let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
80        let addr = listener.local_addr().unwrap();
81        tokio::spawn(async move {
82            let (stream, _) = listener.accept().await.unwrap();
83            let mut ws = tokio_tungstenite::accept_async(stream).await.unwrap();
84            while let Some(Ok(Message::Text(t))) = ws.next().await {
85                let req: Value = serde_json::from_str(&t).unwrap();
86                let id = req["id"].as_u64().unwrap();
87                let method = req["method"].as_str().unwrap_or("");
88                let result = match method {
89                    "Target.getTargets" => json!({"targetInfos": targets.clone()}),
90                    "Target.attachToTarget" => json!({"sessionId": "S1"}),
91                    "Runtime.evaluate" => json!({"result": {"value": eval_value.clone()}}),
92                    _ => json!({}),
93                };
94                let resp = json!({"id": id, "result": result});
95                ws.send(Message::Text(resp.to_string())).await.unwrap();
96            }
97        });
98        format!("ws://{addr}")
99    }
100
101    #[tokio::test]
102    async fn eval_mock_returns_string() {
103        let url = spawn_cdp_mock(
104            vec![json!({"targetId":"a","type":"page","url":"https://example.com/"})],
105            json!("hello"),
106        )
107        .await;
108        let s = PageSession::attach(&url, Engine::Cdp, None).await.unwrap();
109        let v = s.evaluate("'hello'", false).await.unwrap();
110        s.close().await;
111        assert_eq!(format_output(&v, false), "hello");
112    }
113
114    #[tokio::test]
115    async fn eval_mock_returns_object_json() {
116        let url = spawn_cdp_mock(
117            vec![json!({"targetId":"a","type":"page","url":"https://example.com/"})],
118            json!({"a": 1}),
119        )
120        .await;
121        let s = PageSession::attach(&url, Engine::Cdp, None).await.unwrap();
122        let v = s.evaluate("({a:1})", false).await.unwrap();
123        s.close().await;
124        let out = format_output(&v, true);
125        let parsed: Value = serde_json::from_str(&out).unwrap();
126        assert_eq!(parsed, json!({"a": 1}));
127    }
128}
browser_control/cli/eval.rs

browser_control/cli/
eval.rs
