feat: support Brave + Chrome channels, fix stale DevToolsActivePort discovery (#13)

* feat: support Brave + Chrome channels, fix stale DevToolsActivePort discovery

Broadens browser detection and hardens CDP endpoint discovery, based on the
investigation and approach in #4 (Brave Beta on macOS with a leftover Chrome
DevToolsActivePort file).

Browser detection (src/setup.ts, src/cdp/discovery.ts):
- checkChromeRunning() now recognizes Brave (macOS "brave browser", Linux
  brave/brave-browser, Windows brave.exe), alongside the existing Chrome/
  Chromium/Edge detection. Also excludes gpu/updater sub-processes that can
  linger after a browser quits.
- profileDirs() gains Brave (Stable/Beta/Nightly/Dev) and Chrome Beta/Dev/
  Canary/Chromium profile paths across macOS, Linux, and Windows.

Stale DevToolsActivePort handling (src/cdp/discovery.ts):
Previously discovery trusted the first readable DevToolsActivePort file. A
browser that has quit leaves its file behind, so if another browser later binds
the same port (e.g. 9222), discovery returned a WS URL carrying the dead
browser's UUID against the live browser's server, and the connection failed.
discoverWsUrl() now:
- collects all readable candidates instead of committing to the first;
- when candidates share a port, keeps the most-recently-written file (mtime);
- skips candidates whose port isn't live via a fast single-shot probe (no
  30s waitForPort block on stale files);
- asks each live browser for its canonical webSocketDebuggerUrl via
  /json/version, falling back to the file's WS path when that endpoint is
  disabled (some browsers only expose it via --remote-debugging-port);
- falls back to probing well-known ports (9222, plus BU_CDP_PORTS) when no
  profile file is readable — covering sandboxed harnesses (EPERM/EACCES) and
  non-default install locations.

Setup guidance updated to mention brave://inspect / edge://inspect and the
--remote-debugging-port launch flag.

Verified: typecheck clean; queryLiveWsUrl / mtime-dedup / fallback-port logic
exercised against a mock /json/version server; checkChromeRunning() matches the
single main process against live macOS ps output, excluding all helpers.

Closes #4

Co-authored-by: Trevor Whitney <trevorjwhitney@gmail.com>

* fix: harden discovery against malformed port files + stale-then-fallback

Addresses two issues raised in review of the discovery rewrite:

- Validate the port parsed from DevToolsActivePort before building a
  candidate. A truncated/corrupt file (non-numeric or out-of-range first
  line) yielded NaN, and net.connect throws ERR_SOCKET_BAD_PORT
  synchronously for NaN / <=0 / >=65536 — which escaped discoverWsUrl as an
  unhandled rejection instead of surfacing as a Result error. Such entries
  are now skipped.

- Fall back to well-known ports (9222 / BU_CDP_PORTS) after all discovered
  candidates prove stale. Previously the fallback ran only when no port file
  was readable, so a leftover file for a quit browser caused a ~30s
  waitForPort block and failure without ever trying a live fallback port.
  Ports already covered by a candidate are skipped to avoid re-probing.

---------

Co-authored-by: Trevor Whitney <trevorjwhitney@gmail.com>

1 files changed, 24 insertions, 9 deletions

diff --git a/src/setup.ts b/src/setup.ts
index 1ff7c36..40f501c 100644
--- a/src/setup.ts
+++ b/src/setup.ts
@@ -60,9 +60,12 @@ export async function performSetup(client: BrowserClient): Promise<SetupResult>
       return {
         success: false,
         error:
-          "Chrome remote debugging needs to be enabled.\n\n" +
-          'Open chrome://inspect/#remote-debugging in your browser, tick the\n' +
+          "Browser remote debugging needs to be enabled.\n\n" +
+          "Open chrome://inspect/#remote-debugging (or brave://inspect,\n" +
+          "edge://inspect) in your browser, tick the\n" +
           '"Discover network targets" / Allow checkbox, then retry.\n\n' +
+          "If that doesn't expose DevTools, relaunch the browser with\n" +
+          "--remote-debugging-port=9222.\n\n" +
           "Or set BU_CDP_WS to a remote browser WebSocket URL.",
       };
     }
@@ -90,19 +93,31 @@ export async function performSetup(client: BrowserClient): Promise<SetupResult>
 function checkChromeRunning(): boolean {
   try {
     if (process.platform === "darwin") {
-      // ps -o comm= returns the full executable path on modern macOS.
-      // We check for "Google Chrome" anywhere in the path (case-insensitive),
-      // excluding helper/renderer subprocesses.
+      // ps -o comm= returns the full executable path on modern macOS, e.g.
+      // "/Applications/Brave Browser.app/Contents/MacOS/Brave Browser". We check
+      // for a known Chromium-family name anywhere in the path (case-insensitive),
+      // excluding helper/renderer/gpu/crashpad/updater subprocesses that linger
+      // after the user quits the browser.
       const out = execSync("ps -A -o comm=", { timeout: 5000 }).toString().toLowerCase();
       const lines = out.split("\n").map((l) => l.trim()).filter(Boolean);
+      const browserNames = ["google chrome", "chromium", "microsoft edge", "brave browser"];
       return lines.some((l) => {
-        if (l.includes("helper") || l.includes("renderer") || l.includes("crashpad")) return false;
-        return l.includes("google chrome") || l.includes("chromium") || l.includes("microsoft edge");
+        if (
+          l.includes("helper") ||
+          l.includes("renderer") ||
+          l.includes("crashpad") ||
+          l.includes(" gpu") ||
+          l.includes("updater")
+        ) return false;
+        return browserNames.some((name) => l.includes(name));
       });
     } else if (process.platform === "linux") {
       const out = execSync("ps -A -o comm=,args=", { timeout: 5000 }).toString().toLowerCase();
       const lines = out.split("\n").map((l) => l.trim()).filter(Boolean);
-      const browserComms = ["chrome", "chromium", "chromium-browser", "msedge", "microsoft-edge", "google-chrome"];
+      const browserComms = [
+        "chrome", "chromium", "chromium-browser", "msedge", "microsoft-edge",
+        "google-chrome", "brave", "brave-browser",
+      ];
       return lines.some((line) => {
         const parts = line.split(/\s+/);
         const comm = parts[0] ?? "";
@@ -112,7 +127,7 @@ function checkChromeRunning(): boolean {
       });
     } else if (process.platform === "win32") {
       const out = execSync("tasklist", { timeout: 5000 }).toString().toLowerCase();
-      return ["chrome.exe", "msedge.exe"].some((n) => out.includes(n));
+      return ["chrome.exe", "msedge.exe", "brave.exe"].some((n) => out.includes(n));
     }
   } catch {
     // best-effort