swink_agent_plugin_web/

playwright.rs

use std::collections::HashMap;
use std::path::{Path, PathBuf};
use std::process::Stdio;
use std::sync::atomic::{AtomicU64, Ordering};
use std::time::{Duration, SystemTime, UNIX_EPOCH};

use serde::{Deserialize, Serialize};
use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader, BufWriter};
use tokio::process::{Child, Command};

use crate::domain::DomainFilter;

/// Viewport dimensions for screenshots.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Viewport {
    pub width: u32,
    pub height: u32,
}

/// Preset extraction types.
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "lowercase")]
pub enum ExtractionPreset {
    Links,
    Headings,
    Tables,
}

/// A single extracted element from a web page.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct ExtractedElement {
    pub tag: String,
    pub text: String,
    pub attributes: HashMap<String, String>,
}

/// Screenshot response plus the browser's final URL after redirects.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ScreenshotOutput {
    pub base64: String,
    pub final_url: String,
}

/// Extraction response plus the browser's final URL after redirects.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ExtractOutput {
    pub elements: Vec<ExtractedElement>,
    pub final_url: String,
}

#[derive(Debug, Clone, Serialize)]
#[serde(rename_all = "camelCase")]
pub(crate) struct BrowserNavigationFilter {
    allowlist: Vec<String>,
    denylist: Vec<String>,
    block_private_ips: bool,
}

/// Request sent to the Playwright bridge subprocess.
#[derive(Debug, Serialize)]
#[serde(tag = "action", rename_all = "lowercase")]
pub enum PlaywrightRequest {
    Screenshot {
        id: u64,
        url: String,
        viewport: Option<Viewport>,
        filter: Option<BrowserNavigationFilter>,
    },
    Extract {
        id: u64,
        url: String,
        selector: Option<String>,
        preset: Option<ExtractionPreset>,
        filter: Option<BrowserNavigationFilter>,
    },
    Ping {
        id: u64,
    },
}

/// Response from the Playwright bridge subprocess.
#[derive(Debug, Deserialize)]
pub struct PlaywrightResponse {
    pub id: u64,
    pub ok: bool,
    pub data: Option<serde_json::Value>,
    pub error: Option<String>,
}

/// Errors from the Playwright bridge.
#[derive(Debug, thiserror::Error)]
pub enum PlaywrightError {
    #[error(
        "Playwright/Node.js not found. Install with: npm install -g playwright && npx playwright install chromium"
    )]
    NotInstalled,
    #[error("Bridge communication error: {0}")]
    Communication(String),
    #[error("Bridge returned error: {0}")]
    BridgeError(String),
    #[error("Operation timed out after {0:?}")]
    Timeout(Duration),
    #[error("IO error: {0}")]
    Io(#[from] std::io::Error),
}

/// Default timeout for bridge operations (30 seconds).
const DEFAULT_TIMEOUT: Duration = Duration::from_secs(30);
const BRIDGE_SCRIPT: &str = include_str!("playwright_bridge.js");
static BRIDGE_SCRIPT_COUNTER: AtomicU64 = AtomicU64::new(0);

/// Bridge to a Playwright Node.js subprocess for headless browser operations.
///
/// Spawns a child process running the embedded `playwright_bridge.js` script
/// and communicates via JSON lines on stdin/stdout.
pub struct PlaywrightBridge {
    _child: Child,
    stdin: BufWriter<tokio::process::ChildStdin>,
    stdout: BufReader<tokio::process::ChildStdout>,
    next_id: AtomicU64,
    /// Path to the temp JS file — kept alive for the process lifetime.
    _bridge_script: PathBuf,
}

impl PlaywrightBridge {
    /// Start the Playwright bridge subprocess.
    ///
    /// Writes the embedded bridge JS to a temp file, spawns `node` to run it,
    /// and verifies the bridge is alive with a ping.
    ///
    /// `playwright_path` optionally overrides the Node.js binary path.
    pub async fn start(playwright_path: Option<&Path>) -> Result<Self, PlaywrightError> {
        let script_path = write_bridge_script_temp_file().await?;

        // Resolve node binary path.
        let node_path = resolve_node_path(playwright_path);

        // Spawn the bridge process.
        let mut child = Command::new(&node_path)
            .arg(&script_path)
            .stdin(Stdio::piped())
            .stdout(Stdio::piped())
            .stderr(Stdio::null())
            .kill_on_drop(true)
            .spawn()
            .map_err(|e| {
                if e.kind() == std::io::ErrorKind::NotFound {
                    PlaywrightError::NotInstalled
                } else {
                    PlaywrightError::Io(e)
                }
            })?;

        let stdin = child
            .stdin
            .take()
            .ok_or_else(|| PlaywrightError::Communication("failed to open stdin".into()))?;
        let stdout = child
            .stdout
            .take()
            .ok_or_else(|| PlaywrightError::Communication("failed to open stdout".into()))?;

        let mut bridge = Self {
            _child: child,
            stdin: BufWriter::new(stdin),
            stdout: BufReader::new(stdout),
            next_id: AtomicU64::new(1),
            _bridge_script: script_path,
        };

        // Verify the bridge is alive.
        let id = bridge.next_id();
        let resp = bridge.send_request(PlaywrightRequest::Ping { id }).await?;
        if !resp.ok {
            return Err(PlaywrightError::Communication(
                resp.error.unwrap_or_else(|| "ping failed".into()),
            ));
        }

        Ok(bridge)
    }

    /// Send a request to the bridge and return the response.
    ///
    /// Applies a 30-second timeout to the entire operation.
    pub async fn send_request(
        &mut self,
        request: PlaywrightRequest,
    ) -> Result<PlaywrightResponse, PlaywrightError> {
        let result = tokio::time::timeout(DEFAULT_TIMEOUT, self.send_request_inner(request)).await;
        match result {
            Ok(inner) => inner,
            Err(_) => Err(PlaywrightError::Timeout(DEFAULT_TIMEOUT)),
        }
    }

    /// Take a screenshot of a web page and return the base64-encoded PNG.
    pub async fn screenshot(
        &mut self,
        url: &str,
        viewport: Option<Viewport>,
        domain_filter: Option<&DomainFilter>,
    ) -> Result<ScreenshotOutput, PlaywrightError> {
        let id = self.next_id();
        let resp = self
            .send_request(PlaywrightRequest::Screenshot {
                id,
                url: url.to_owned(),
                viewport,
                filter: domain_filter.map(BrowserNavigationFilter::from),
            })
            .await?;

        if !resp.ok {
            return Err(PlaywrightError::BridgeError(
                resp.error.unwrap_or_else(|| "screenshot failed".into()),
            ));
        }

        parse_screenshot_data(resp.data, url)
    }

    /// Extract elements from a web page using a CSS selector or preset.
    pub async fn extract(
        &mut self,
        url: &str,
        selector: Option<&str>,
        preset: Option<ExtractionPreset>,
        domain_filter: Option<&DomainFilter>,
    ) -> Result<ExtractOutput, PlaywrightError> {
        let id = self.next_id();
        let resp = self
            .send_request(PlaywrightRequest::Extract {
                id,
                url: url.to_owned(),
                selector: selector.map(String::from),
                preset,
                filter: domain_filter.map(BrowserNavigationFilter::from),
            })
            .await?;

        if !resp.ok {
            return Err(PlaywrightError::BridgeError(
                resp.error.unwrap_or_else(|| "extraction failed".into()),
            ));
        }

        parse_extract_data(resp.data, url)
    }

    // ── Internals ──────────────────────────────────────────────────────────

    fn next_id(&self) -> u64 {
        self.next_id.fetch_add(1, Ordering::Relaxed)
    }

    async fn send_request_inner(
        &mut self,
        request: PlaywrightRequest,
    ) -> Result<PlaywrightResponse, PlaywrightError> {
        let mut line = serde_json::to_string(&request)
            .map_err(|e| PlaywrightError::Communication(format!("serialize error: {e}")))?;
        line.push('\n');

        self.stdin
            .write_all(line.as_bytes())
            .await
            .map_err(|e| PlaywrightError::Communication(format!("write error: {e}")))?;
        self.stdin
            .flush()
            .await
            .map_err(|e| PlaywrightError::Communication(format!("flush error: {e}")))?;

        let mut response_line = String::new();
        let bytes_read = self
            .stdout
            .read_line(&mut response_line)
            .await
            .map_err(|e| PlaywrightError::Communication(format!("read error: {e}")))?;

        if bytes_read == 0 {
            return Err(PlaywrightError::Communication(
                "bridge process closed stdout".into(),
            ));
        }

        let response: PlaywrightResponse = serde_json::from_str(&response_line)
            .map_err(|e| PlaywrightError::Communication(format!("deserialize error: {e}")))?;

        let expected_id = match &request {
            PlaywrightRequest::Screenshot { id, .. }
            | PlaywrightRequest::Extract { id, .. }
            | PlaywrightRequest::Ping { id } => *id,
        };

        if response.id != expected_id {
            return Err(PlaywrightError::Communication(format!(
                "response id mismatch: expected {expected_id}, got {}",
                response.id
            )));
        }

        Ok(response)
    }
}

impl From<&DomainFilter> for BrowserNavigationFilter {
    fn from(filter: &DomainFilter) -> Self {
        Self {
            allowlist: filter.allowlist.clone(),
            denylist: filter.denylist.clone(),
            block_private_ips: filter.block_private_ips,
        }
    }
}

fn parse_screenshot_data(
    data: Option<serde_json::Value>,
    requested_url: &str,
) -> Result<ScreenshotOutput, PlaywrightError> {
    let data =
        data.ok_or_else(|| PlaywrightError::Communication("missing screenshot data".into()))?;

    if let Some(base64) = data.as_str() {
        return Ok(ScreenshotOutput {
            base64: base64.to_owned(),
            final_url: requested_url.to_owned(),
        });
    }

    let base64 = data
        .get("image")
        .and_then(serde_json::Value::as_str)
        .ok_or_else(|| PlaywrightError::Communication("missing screenshot image data".into()))?
        .to_owned();
    let final_url = data
        .get("finalUrl")
        .and_then(serde_json::Value::as_str)
        .unwrap_or(requested_url)
        .to_owned();

    Ok(ScreenshotOutput { base64, final_url })
}

fn parse_extract_data(
    data: Option<serde_json::Value>,
    requested_url: &str,
) -> Result<ExtractOutput, PlaywrightError> {
    let data =
        data.ok_or_else(|| PlaywrightError::Communication("missing extraction data".into()))?;

    if data.is_array() {
        let elements = serde_json::from_value(data).map_err(|error| {
            PlaywrightError::Communication(format!("failed to parse elements: {error}"))
        })?;
        return Ok(ExtractOutput {
            elements,
            final_url: requested_url.to_owned(),
        });
    }

    let elements_value = data
        .get("elements")
        .cloned()
        .ok_or_else(|| PlaywrightError::Communication("missing extraction elements".into()))?;
    let elements = serde_json::from_value(elements_value).map_err(|error| {
        PlaywrightError::Communication(format!("failed to parse elements: {error}"))
    })?;
    let final_url = data
        .get("finalUrl")
        .and_then(serde_json::Value::as_str)
        .unwrap_or(requested_url)
        .to_owned();

    Ok(ExtractOutput {
        elements,
        final_url,
    })
}

async fn write_bridge_script_temp_file() -> Result<PathBuf, PlaywrightError> {
    let sequence = BRIDGE_SCRIPT_COUNTER.fetch_add(1, Ordering::Relaxed);
    let timestamp = SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .map_or(0, |duration| duration.as_nanos());
    let script_path = std::env::temp_dir().join(format!(
        "swink_playwright_bridge_{}_{}_{}.js",
        std::process::id(),
        timestamp,
        sequence
    ));

    tokio::fs::write(&script_path, BRIDGE_SCRIPT).await?;
    Ok(script_path)
}

/// Resolve the path to the `node` binary.
///
/// Priority: explicit path > `which node` > bare `"node"`.
fn resolve_node_path(explicit: Option<&Path>) -> PathBuf {
    if let Some(p) = explicit {
        return p.to_path_buf();
    }

    // Try `which node` synchronously (called once at startup, acceptable).
    if let Ok(output) = std::process::Command::new("which").arg("node").output()
        && output.status.success()
    {
        let path_str = String::from_utf8_lossy(&output.stdout).trim().to_owned();
        if !path_str.is_empty() {
            return PathBuf::from(path_str);
        }
    }

    PathBuf::from("node")
}

#[cfg(test)]
mod tests {
    use std::collections::HashSet;
    use std::path::Path;
    use std::process::Command as StdCommand;

    use serde_json::json;

    use super::{
        BRIDGE_SCRIPT, parse_extract_data, parse_screenshot_data, resolve_node_path,
        write_bridge_script_temp_file,
    };

    #[tokio::test]
    async fn writes_unique_bridge_scripts_for_concurrent_startups() {
        let handles = (0..8).map(|_| tokio::spawn(write_bridge_script_temp_file()));
        let mut paths = Vec::new();

        for handle in handles {
            let path = handle
                .await
                .expect("task should complete")
                .expect("temp script creation should succeed");
            paths.push(path);
        }

        let unique_paths: HashSet<_> = paths.iter().cloned().collect();
        assert_eq!(unique_paths.len(), paths.len());

        for path in &paths {
            let contents = tokio::fs::read_to_string(path)
                .await
                .expect("script contents should be readable");
            assert_eq!(contents, BRIDGE_SCRIPT);
            tokio::fs::remove_file(path)
                .await
                .expect("temp script cleanup should succeed");
        }
    }

    #[test]
    fn bridge_script_blocks_special_use_hosts() {
        let bridge_path = Path::new(env!("CARGO_MANIFEST_DIR")).join("src/playwright_bridge.js");
        let node_script = format!(
            r"
const bridge = require({bridge_path});

for (const host of [
  '0.0.0.0',
  '100.64.0.1',
  '198.18.0.1',
  '192.0.2.1',
  '224.0.0.1',
  '::',
  '::1',
  'fc00::1',
  'fd00::1',
  'fe80::1',
  'ff02::1',
  '2001:db8::1',
  '::ffff:10.0.0.1',
  '::ffff:127.0.0.1',
  '0:0:0:0:0:ffff:c0a8:0101',
]) {{
  if (!bridge.isBlockedPrivateHost(host)) {{
    throw new Error('private host should be blocked: ' + host);
  }}
}}
for (const host of ['93.184.216.34', '2606:4700:4700::1111', '::ffff:93.184.216.34']) {{
  if (bridge.isBlockedPrivateHost(host)) {{
    throw new Error('public host should not be blocked: ' + host);
  }}
}}
",
            bridge_path = serde_json::to_string(&bridge_path.display().to_string())
                .expect("path should serialize"),
        );

        let output = StdCommand::new(resolve_node_path(None))
            .arg("-e")
            .arg(node_script)
            .output()
            .expect("node should run bridge host assertions");

        assert!(
            output.status.success(),
            "node assertions failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );
    }

    #[test]
    fn bridge_script_filters_requests_without_playwright() {
        let bridge_path = Path::new(env!("CARGO_MANIFEST_DIR")).join("src/playwright_bridge.js");
        let node_script = format!(
            r"
const bridge = require({bridge_path});

void (async () => {{
async function resolvesTo(addresses) {{
  return addresses.map((address) => {{
    const family = address.includes(':') ? 6 : 4;
    return {{ address, family }};
  }});
}}

if (!bridge.isBlockedPrivateHost('127.0.0.1') || !bridge.isBlockedPrivateHost('localhost')) {{
  throw new Error('private host detection failed');
}}
if (await bridge.blockedByFilter('https://evil.com/path', {{ allowlist: [], denylist: ['evil.com'], blockPrivateIps: true }}) === null) {{
  throw new Error('denylist filter failed');
}}
if (await bridge.blockedByFilter('http://127.0.0.1/admin', {{ allowlist: [], denylist: [], blockPrivateIps: true }}) === null) {{
  throw new Error('private IP filter failed');
}}
if (await bridge.blockedByFilter(
  'https://internal.example/admin',
  {{ allowlist: [], denylist: [], blockPrivateIps: true }},
  async () => resolvesTo(['10.0.0.5'])
) === null) {{
  throw new Error('resolved private subresource filter failed');
}}
if (await bridge.blockedByFilter(
  'https://public.example/',
  {{ allowlist: [], denylist: [], blockPrivateIps: true }},
  async () => resolvesTo(['93.184.216.34'])
) !== null) {{
  throw new Error('public resolved address should not be blocked');
}}
if (!String(await bridge.blockedByFilter(
  'https://unresolvable.example/',
  {{ allowlist: [], denylist: [], blockPrivateIps: true }},
  async () => {{ throw new Error('lookup failed'); }}
)).includes('DNS resolution failed')) {{
  throw new Error('DNS failures should fail closed');
}}
}})().catch((error) => {{
  console.error(error.stack || error);
  process.exit(1);
}});
",
            bridge_path = serde_json::to_string(&bridge_path.display().to_string())
                .expect("path should serialize"),
        );

        let output = StdCommand::new(resolve_node_path(None))
            .arg("-e")
            .arg(node_script)
            .output()
            .expect("node should run bridge filter assertions");

        assert!(
            output.status.success(),
            "node assertions failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );
    }

    #[test]
    fn bridge_script_uses_context_routing_with_service_workers_blocked() {
        let bridge_path = Path::new(env!("CARGO_MANIFEST_DIR")).join("src/playwright_bridge.js");
        let node_script = format!(
            r"
const bridge = require({bridge_path});

void (async () => {{
const options = bridge.newContextOptions({{ viewport: {{ width: 640, height: 480 }} }});
if (options.serviceWorkers !== 'block') {{
  throw new Error('service workers should be blocked for routed browser contexts');
}}
if (options.viewport.width !== 640 || options.viewport.height !== 480) {{
  throw new Error('viewport options were not preserved: ' + JSON.stringify(options));
}}
const proxiedOptions = bridge.newContextOptions(
  {{ viewport: {{ width: 800, height: 600 }} }},
  {{ server: 'http://127.0.0.1:43210' }}
);
if (proxiedOptions.proxy.server !== 'http://127.0.0.1:43210') {{
  throw new Error('proxy options were not installed: ' + JSON.stringify(proxiedOptions));
}}

let pattern = null;
let abortReason = null;
const context = {{
  async route(routePattern, handler) {{
    pattern = routePattern;
    await handler({{
      request() {{
        return {{ url() {{ return 'http://127.0.0.1/admin'; }} }};
      }},
      async abort(reason) {{ abortReason = reason; }},
      async continue() {{ throw new Error('blocked private request should not continue'); }},
    }});
  }},
}};

const blockedReason = await bridge.installNavigationFilter(
  context,
  {{ allowlist: [], denylist: [], blockPrivateIps: true }}
);
if (pattern !== '**/*') {{
  throw new Error('context route should cover all requests, got: ' + pattern);
}}
if (abortReason !== 'blockedbyclient') {{
  throw new Error('blocked request should be aborted by client, got: ' + abortReason);
}}
if (!String(blockedReason()).includes('private/internal host')) {{
  throw new Error('blocked reason was not retained: ' + blockedReason());
}}
}})().catch((error) => {{
  console.error(error.stack || error);
  process.exit(1);
}});
",
            bridge_path = serde_json::to_string(&bridge_path.display().to_string())
                .expect("path should serialize"),
        );

        let output = StdCommand::new(resolve_node_path(None))
            .arg("-e")
            .arg(node_script)
            .output()
            .expect("node should run bridge context routing assertions");

        assert!(
            output.status.success(),
            "node assertions failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );
    }

    #[test]
    fn bridge_script_resolves_proxy_targets_with_single_checked_address() {
        let bridge_path = Path::new(env!("CARGO_MANIFEST_DIR")).join("src/playwright_bridge.js");
        let node_script = format!(
            r"
const bridge = require({bridge_path});

void (async () => {{
async function resolvesTo(addresses) {{
  return addresses.map((address) => {{
    const family = address.includes(':') ? 6 : 4;
    return {{ address, family }};
  }});
}}

const filter = {{ allowlist: [], denylist: [], blockPrivateIps: true }};
if (!bridge.filterNeedsProxy(filter)) {{
  throw new Error('private-IP filtering should enable the browser proxy');
}}

const target = await bridge.resolveProxyTarget(
  new URL('https://public.example/path?q=1'),
  filter,
  async () => resolvesTo(['93.184.216.34'])
);
if (target.address !== '93.184.216.34' || target.host !== 'public.example' || target.port !== 443) {{
  throw new Error('unexpected proxy target: ' + JSON.stringify(target));
}}

try {{
  await bridge.resolveProxyTarget(
    new URL('https://rebind.example/'),
    filter,
    async () => resolvesTo(['93.184.216.34', '10.0.0.5'])
  );
  throw new Error('mixed public/private DNS answers should fail closed');
}} catch (error) {{
  if (!String(error.message).includes('private/internal host')) {{
    throw error;
  }}
}}

try {{
  await bridge.resolveProxyTarget(
    new URL('https://unresolvable.example/'),
    filter,
    async () => {{ throw new Error('lookup failed'); }}
  );
  throw new Error('DNS lookup failures should fail closed');
}} catch (error) {{
  if (!String(error.message).includes('DNS resolution failed')) {{
    throw error;
  }}
}}
}})().catch((error) => {{
  console.error(error.stack || error);
  process.exit(1);
}});
",
            bridge_path = serde_json::to_string(&bridge_path.display().to_string())
                .expect("path should serialize"),
        );

        let output = StdCommand::new(resolve_node_path(None))
            .arg("-e")
            .arg(node_script)
            .output()
            .expect("node should run bridge proxy assertions");

        assert!(
            output.status.success(),
            "node assertions failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );
    }

    #[test]
    fn bridge_script_exports_data_only_extract_helpers() {
        assert!(!BRIDGE_SCRIPT.contains("eval("));

        let bridge_path = Path::new(env!("CARGO_MANIFEST_DIR")).join("src/playwright_bridge.js");
        let node_script = format!(
            r"
const bridge = require({bridge_path});

const linksPlan = bridge.buildExtractionPlan({{ preset: 'links' }});
if (linksPlan.selector !== 'a[href]' || linksPlan.preset !== 'links') {{
  throw new Error('unexpected links plan: ' + JSON.stringify(linksPlan));
}}

const selectorPlan = bridge.buildExtractionPlan({{ selector: '.card' }});
if (selectorPlan.selector !== '.card' || selectorPlan.preset !== null) {{
  throw new Error('unexpected selector plan: ' + JSON.stringify(selectorPlan));
}}

const customElement = bridge.extractElementData(
  {{
    tagName: 'DIV',
    textContent: '  Hello world  ',
    attributes: [{{ name: 'data-id', value: '42' }}],
    getAttribute(name) {{
      return name === 'data-id' ? '42' : null;
    }},
    innerHTML: '<span>Hello world</span>',
  }},
  null
);
if (customElement.tag !== 'div' || customElement.text !== 'Hello world' || customElement.attributes['data-id'] !== '42') {{
  throw new Error('unexpected custom element: ' + JSON.stringify(customElement));
}}

const linkElement = bridge.extractElementData(
  {{
    tagName: 'A',
    textContent: ' Docs ',
    attributes: [{{ name: 'href', value: '/docs' }}],
    getAttribute(name) {{
      return name === 'href' ? '/docs' : null;
    }},
    innerHTML: 'Docs',
  }},
  'links'
);
if (linkElement.attributes.href !== '/docs' || Object.keys(linkElement.attributes).length !== 1) {{
  throw new Error('unexpected link element: ' + JSON.stringify(linkElement));
}}

const headingElement = bridge.extractElementData(
  {{
    tagName: 'H2',
    textContent: ' Section ',
    attributes: [{{ name: 'id', value: 'section' }}],
    getAttribute() {{
      return null;
    }},
    innerHTML: 'Section',
  }},
  'headings'
);
if (headingElement.tag !== 'h2' || headingElement.text !== 'Section' || Object.keys(headingElement.attributes).length !== 0) {{
  throw new Error('unexpected heading element: ' + JSON.stringify(headingElement));
}}

const tableElement = bridge.extractElementData(
  {{
    tagName: 'TABLE',
    textContent: '',
    attributes: [],
    getAttribute() {{
      return null;
    }},
    innerHTML: '<tbody><tr><td>value</td></tr></tbody>',
  }},
  'tables'
);
if (tableElement.tag !== 'table' || !tableElement.text.includes('<tbody>')) {{
  throw new Error('unexpected table element: ' + JSON.stringify(tableElement));
}}
",
            bridge_path = serde_json::to_string(&bridge_path.display().to_string())
                .expect("path should serialize"),
        );

        let output = StdCommand::new(resolve_node_path(None))
            .arg("-e")
            .arg(node_script)
            .output()
            .expect("node should run bridge helper assertions");

        assert!(
            output.status.success(),
            "node assertions failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );
    }

    #[test]
    fn screenshot_data_carries_final_url() {
        let output = parse_screenshot_data(
            Some(json!({
                "image": "abc123",
                "finalUrl": "https://example.com/final",
            })),
            "https://example.com/start",
        )
        .unwrap();

        assert_eq!(output.base64, "abc123");
        assert_eq!(output.final_url, "https://example.com/final");
    }

    #[test]
    fn extract_data_carries_final_url() {
        let output = parse_extract_data(
            Some(json!({
                "elements": [
                    {
                        "tag": "a",
                        "text": "Docs",
                        "attributes": { "href": "/docs" },
                    }
                ],
                "finalUrl": "https://example.com/final",
            })),
            "https://example.com/start",
        )
        .unwrap();

        assert_eq!(output.final_url, "https://example.com/final");
        assert_eq!(output.elements.len(), 1);
        assert_eq!(output.elements[0].tag, "a");
    }
}