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[ai-assisted] Work around COOP issues with BroadcastChannel and local… #616

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Merged
jpolitz merged 2 commits into from
Feb 2, 2026
+97 −8
Merged

[ai-assisted] Work around COOP issues with BroadcastChannel and local… #616

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[ai-assisted] Work around COOP issues with BroadcastChannel and local…
jpolitz Jan 30, 2026
238e617
[blerner-assisted] cleanup() cleanups
jpolitz Jan 30, 2026
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35 changes: 33 additions & 2 deletions src/web/close.html
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Original file line number Diff line number Diff line change
Expand Up @@ -2,8 +2,39 @@
<html>
<head>
<script>
window.opener.postMessage("done", document.location.origin);
window.close()
// Method 1: Traditional postMessage (works when COOP allows window.opener)
if (window.opener) {
try {
window.opener.postMessage("done", document.location.origin);
} catch (e) {
console.warn("postMessage to opener failed:", e);
}
}
else {
console.warn("No window.opener", window.opener);
}

// Method 2: BroadcastChannel (works even when COOP severs window.opener)
// This is the fallback for environments like GoGuardian that inject COOP headers
if (typeof BroadcastChannel !== 'undefined') {
try {
let channel = new BroadcastChannel('pyret_auth');
channel.postMessage({ type: 'auth_complete' });
channel.close();
} catch (e) {
console.warn("BroadcastChannel failed:", e);
}
}

// Method 3: localStorage fallback for very old browsers without BroadcastChannel
// The opener can detect this via the 'storage' event
try {
localStorage.setItem('pyret_auth_complete', Date.now().toString());
} catch (e) {
console.warn("localStorage fallback failed:", e);
}

window.close();
</script>
</head>
</html>
70 changes: 64 additions & 6 deletions src/web/js/google-apis/api-wrapper.js
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Expand Up @@ -51,15 +51,73 @@ function reauth(immediate, useFullScopes) {
if(useFullScopes) {
path += "&scopes=full";
}
// Need to do a login to get a cookie for this user; do it in a popup
window.addEventListener('message', function(e) {

// Track whether we've already resolved to avoid double-resolution
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@blerner blerner Jan 30, 2026

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This appears to have different semantics than the if we had before, of d.resolve(reauth(...)) or d.result(null)

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@jpolitz jpolitz Jan 30, 2026

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Yeah, it's true. But the resolving-to-null case essentially never happened (that would happen if someone managed to postMessage to the page from some non-Pyret origin).

And resolving to null now makes less sense because the page is waiting for any of the mechanisms to send the response back.

A separate cancellable timer that resolves null would be the right thing. I'd be happy to add that in a separate pass (we don't have anything like that right now)

var resolved = false;
function resolveOnce(method) {
if (!resolved) {
console.log("INFO: Popup login resolved by: ", method);
resolved = true;
// NOTE(joe): A useful thing to do for testing is to comment out this
// cleanup(), and check which of the 3 methods are returning success
// here. cleanup() will stop others from triggering.
cleanup();
d.resolve(reauth(true, useFullScopes));
}
else {
console.log("INFO: Popup login resolved again (ignored): ", method);
}
}

// Cleanup function to remove all listeners
var channel = null;
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@blerner blerner Jan 30, 2026

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This cleanup function doesn't fully cleanup the channel (setting it back to null)

function cleanup() {
window.removeEventListener('message', messageHandler);
window.removeEventListener('storage', storageHandler);
try { localStorage.removeItem('pyret_auth_complete'); } catch (err) {}
if (channel) {
try { channel.close(); }
finally { channel = null; }
}
}

// Method 1: Traditional postMessage (works when COOP allows window.opener)
function messageHandler(e) {
// e.domain appears to not be defined in Firefox
if ((e.domain || e.origin) === document.location.origin) {
d.resolve(reauth(true, useFullScopes));
} else {
d.resolve(null);
resolveOnce("postMessage");
}
});
}
window.addEventListener('message', messageHandler);

// Method 2: BroadcastChannel (works even when COOP severs window.opener)
// This is the fallback for environments like GoGuardian that inject COOP headers
if (typeof BroadcastChannel !== 'undefined') {
try {
channel = new BroadcastChannel('pyret_auth');
channel.onmessage = function(e) {
if (e.data && e.data.type === 'auth_complete') {
resolveOnce("Broadcast");
}
};
} catch (e) {
console.warn("BroadcastChannel setup failed:", e);
}
}

// Method 3: localStorage fallback for very old browsers without BroadcastChannel
function storageHandler(e) {
if (e.key === 'pyret_auth_complete') {
resolveOnce("localStorage");
// Clean up the flag
try { localStorage.removeItem('pyret_auth_complete'); } catch (err) {}
}
}
// Clear any stale auth flag before opening popup
try { localStorage.removeItem('pyret_auth_complete'); } catch (e) {}
window.addEventListener('storage', storageHandler);

// Need to do a login to get a cookie for this user; do it in a popup
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@blerner blerner Jan 30, 2026

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Does this code set up three methods in all circumstances? If so, does cleanup actually clean them all up?

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@jpolitz jpolitz Jan 30, 2026

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Nearly!

You were right that it needed to set channel to null. It also ought to remove the localStorage key. I'll make those changes.

window.open(path);
} else {
// The user is logged in, but needs an access token from our server
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