fix: prevent NoSuchElementException in session chain selection

[developerfred]

close #211

• Replace first() with firstOrNull() in getSelectedChain extension function
• Add null safety check in onSessionApproved to handle empty chains case
• This resolves crash when AppKit.chains list is empty during session approval

[github-actions]

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[developerfred]

I have read the CTA Document and I hereby sign the CTA

[developerfred]

recheck

[jakubuid]

Review: Request Changes

Thanks for the contribution and for identifying a real crash — the NoSuchElementException from first() on an empty AppKit.chains is a valid bug. However, this PR has several issues that need to be addressed before it can be merged.

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P0 — Won't Compile

1. Broken braces/indentation in AppKitDelegate.kt

The onSessionApproved method has its indentation shifted and introduces an extra closing } that would prematurely close the AppKitDelegate object class, leaving onSessionAuthenticateResponse and all subsequent methods outside the class body:

    override fun onSessionApproved(approvedSession: Modal.Model.ApprovedSession) {
    scope.launch {           // ← wrong indent (4sp instead of 8sp)
        val chain = ...
        ...
    }
}                            // ← extra brace closes the object class

2. Missing import android.util.Log

Log.e(...) is used but the import is never added.

3. Nullable return type breaks all other callers

Changing getSelectedChain from ?: first() to ?: firstOrNull() changes the return type from Modal.Model.Chain to Modal.Model.Chain?. Only onSessionApproved is updated, but the same function is called in several other places that still assume a non-null return:

• AppKitDelegate.onSessionAuthenticateResponse — accesses chain.id without null check
• AppKitDelegate.onSessionUpdate — passes chain to toSession() without null check
• AppKitEngine.connectCoinbase — passes chain to toSession() without null check
• AppKitState.mapToAccountButtonState — accesses selectedChain.chainImage, .chainName etc. without null check

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P1 — Behavioral Issues

4. Silent session event drop

When chain is null in onSessionApproved, the event emission (_wcEventModels.emit(approvedSession)) is skipped. Downstream listeners (UI, state management) will never learn the session was approved, which could cause the modal to hang or appear broken. Silently swallowing events can be harder to debug than the original crash.

5. getChain() still throws

The change from AppKit.chains.first() to AppKit.chains.firstOrNull() ?: throw IllegalStateException(...) just swaps one exception type for another — not a meaningful improvement.

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P2 — Unnecessary Changes

6. getDefaultChain() refactoring is a no-op

The original code already returns emptyList() when there are no valid chains, since mapNotNull on an empty list returns an empty list. The added if (chainIds.isNotEmpty()) check is redundant.

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Suggestions for a revised approach

1. Keep getSelectedChain non-nullable and guard at specific call sites, OR make it nullable and update all callers consistently — not just one.
2. Don't silently drop session events — either always emit the event, or propagate the error through onError() so the UI can react.
3. Investigate the root cause: why is AppKit.chains empty during onSessionApproved? This may indicate an initialization ordering issue that should be fixed upstream rather than papered over with null checks at every call site.
4. Maintain the existing 4-space indentation consistent with the rest of the file.

@developerfred Please address the feedback, or let me know so I can push it