fix(peergov): initial peers and guard against nil

[wolf31o2]

Summary by cubic

Initialize the peers slice in NewPeerGovernor and skip nil entries in LoadTopologyConfig. This prevents nil-pointer panics during topology cleanup and ensures a predictable empty state.

^{Written for commit b9770b0. Summary will update automatically on new commits.}

Summary by CodeRabbit

• Refactor
  • Improved internal code stability with defensive nil-safety checks to prevent potential runtime errors.

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[coderabbitai]

📝 Walkthrough

Walkthrough

A new peers field (slice of Peer pointers) is added to the PeerGovernor struct in peergov/peergov.go. The NewPeerGovernor constructor initializes this field to an empty slice. In the LoadTopologyConfig method, defensive nil-checking is introduced to safely skip nil entries during topology removal logic. No public function signatures or exported entities are modified; only an internal struct field is added with corresponding initialization and nil-safety handling.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

The changes are straightforward and minimal:

• Simple field initialization in the constructor
• Single defensive nil-check pattern applied during iteration
• No complex logic or behavioral changes
• Repetitive, safety-focused modifications with clear intent

Pre-merge checks and finishing touches

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main changes: initializing the peers slice and adding nil-safety checks in the PeerGovernor logic.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch fix/guard-nil-peer

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[cubic-dev-ai]

No issues found across 1 file

[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (1)

peergov/peergov.go (1)

87-97: Nil-guard when pruning topology-sourced peers prevents panics

The tmpPeer == nil check correctly protects the tmpPeer.Source access and matches the existing defensive pattern elsewhere (GetPeers, startOutboundConnections, peerIndexBy*). Behaviorally, silently skipping nils is safe; if nil entries are not expected under normal operation, you might optionally add a debug-level log here to aid future diagnostics, but it’s not required for correctness.

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between fa47742 and b9770b0.

📒 Files selected for processing (1)

• peergov/peergov.go (2 hunks)

🧰 Additional context used

🧠 Learnings (1)

📓 Common learnings

Learnt from: wolf31o2
Repo: blinklabs-io/dingo PR: 1036
File: peergov/peergov.go:78-105
Timestamp: 2025-11-22T22:57:02.415Z
Learning: In the blinklabs-io/dingo repository, metric names in peergov/peergov.go (specifically cardano_node_metrics_peerSelection_ActivePeers, cardano_node_metrics_peerSelection_EstablishedPeers, and cardano_node_metrics_peerSelection_KnownPeers) use PascalCase to match the Haskell node implementation for ecosystem tooling compatibility between the Haskell node, Amaru, and Dingo.

🧬 Code graph analysis (1)

peergov/peergov.go (1)

peergov/peer.go (1)

• Peer (36-43)

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• GitHub Check: cubic · AI code reviewer
• GitHub Check: nilaway
• GitHub Check: lint
• GitHub Check: go-test (1.24.x, macos-latest)
• GitHub Check: go-test (1.24.x, ubuntu-latest)
• GitHub Check: Analyze (go)

🔇 Additional comments (1)

peergov/peergov.go (1)

51-59: Explicit peers slice initialization is safe and clear

Initializing peers to an empty slice is consistent with how it’s used elsewhere (len checks, range, appends) and avoids any surprises for callers that might rely on a non-nil slice. No issues from a correctness or concurrency standpoint given the existing mutex usage around mutations.