chore: fix beacon proposer cache unit tests (#7335)

* chore: fix beacon proposer cache unit tests

* Assign values to named constants

packages/beacon-node/test/unit/chain/beaconProposerCache.test.ts

@@ -0,0 +1,45 @@
+import {beforeEach, describe, expect, it} from "vitest";
+import {BeaconProposerCache} from "../../../src/chain/beaconProposerCache.js";
+
+describe("BeaconProposerCache", () => {
+  const suggestedFeeRecipient = "0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
+  const feeRecipient1 = "0xbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb";
+  const feeRecipient2 = "0xcccccccccccccccccccccccccccccccccccccccc";
+
+  const validatorIndex1 = 23;
+  const validatorIndex2 = 43;
+  const unknownValidatorIndex = 32;
+
+  let cache: BeaconProposerCache;
+
+  beforeEach(() => {
+    // max 2 items
+    cache = new BeaconProposerCache({suggestedFeeRecipient});
+    cache.add(1, {validatorIndex: validatorIndex1, feeRecipient: feeRecipient1});
+    cache.add(3, {validatorIndex: validatorIndex2, feeRecipient: feeRecipient2});
+  });
+
+  it("get default", () => {
+    expect(cache.getOrDefault(unknownValidatorIndex)).toBe(suggestedFeeRecipient);
+  });
+
+  it("get what has been set", () => {
+    expect(cache.get(validatorIndex1)).toBe(feeRecipient1);
+  });
+
+  it("override and get latest", () => {
+    const newFeeRecipient = "0xdddddddddddddddddddddddddddddddddddddddd";
+    cache.add(5, {validatorIndex: validatorIndex1, feeRecipient: newFeeRecipient});
+    expect(cache.get(validatorIndex1)).toBe(newFeeRecipient);
+  });
+
+  it("prune", () => {
+    cache.prune(4);
+
+    // Default for what has been pruned
+    expect(cache.getOrDefault(validatorIndex1)).toBe(suggestedFeeRecipient);
+
+    // Original for what hasn't been pruned
+    expect(cache.get(validatorIndex2)).toBe(feeRecipient2);
+  });
+});