feat: add chain-specific finalization thresholds

- Add chainConfig with default and chain-specific finalization thresholds
- Add getFinalizationThreshold utility function
- Add tests for configuration and threshold retrieval

src/__tests__/chain-config.test.ts

@@ -0,0 +1,30 @@
+import { getFinalizationThreshold, chainConfig } from '../chain-config';
+
+describe('Chain Configuration', () => {
+  it('should return correct finalization threshold for known chains', () => {
+    expect(getFinalizationThreshold('1')).toBe(25); // Ethereum Mainnet
+    expect(getFinalizationThreshold('10')).toBe(2); // Optimism
+    expect(getFinalizationThreshold('8453')).toBe(4); // Base
+  });
+
+  it('should return default finalization threshold for unknown chains', () => {
+    expect(getFinalizationThreshold('123')).toBe(
+      chainConfig.defaultFinalizationThreshold
+    );
+    expect(getFinalizationThreshold('999')).toBe(
+      chainConfig.defaultFinalizationThreshold
+    );
+  });
+
+  it('should have valid configuration values', () => {
+    // All thresholds should be positive numbers
+    expect(chainConfig.defaultFinalizationThreshold).toBeGreaterThan(0);
+
+    Object.entries(chainConfig.finalizationThresholds).forEach(
+      ([_chainId, threshold]) => {
+        expect(Number.isInteger(threshold)).toBe(true);
+        expect(threshold).toBeGreaterThan(0);
+      }
+    );
+  });
+});

src/chain-config.ts

@@ -0,0 +1,35 @@
+/**
+ * Configuration for chain-specific settings
+ */
+
+export interface ChainConfig {
+  defaultFinalizationThreshold: number;
+  finalizationThresholds: Record<string, number>;
+}
+
+export const chainConfig: ChainConfig = {
+  // Default finalization threshold in seconds
+  defaultFinalizationThreshold: 3,
+
+  // Chain-specific finalization thresholds in seconds
+  finalizationThresholds: {
+    // Ethereum Mainnet
+    '1': 25,
+    // Optimism
+    '10': 2,
+    // Base
+    '8453': 4,
+  },
+};
+
+/**
+ * Get the finalization threshold for a specific chain ID
+ * @param chainId - The chain ID to get the threshold for
+ * @returns The finalization threshold in seconds
+ */
+export function getFinalizationThreshold(chainId: string): number {
+  return (
+    chainConfig.finalizationThresholds[chainId] ??
+    chainConfig.defaultFinalizationThreshold
+  );
+}