Ensure that fee minimum estimate is returned when no estimates

src/lib/DataProviderManager.ts

@@ -218,6 +218,14 @@ export class DataProviderManager {
       });
     }
 
+    // If we don't have any valid estimates that are above the fee minimum, add the minimum fee.
+    if (Object.keys(mergedEstimates).length === 0) {
+      log.warn({
+        msg: `No valid estimates were available. Adding minimum fee of ${this.feeMinimum}.`,
+      });
+      mergedEstimates[1] = this.feeMinimum;
+    }
+
     log.debug({ msg: "Final mergedEstimates:", mergedEstimates });
     return mergedEstimates;
   }

test/DataProviderManager-minfee.test.ts

@@ -0,0 +1,73 @@
+import { expect, test } from "bun:test";
+import { DataProviderManager } from "../src/lib/DataProviderManager";
+
+test("should exclude estimates that are below the fee minimum", async () => {
+  const feeEstimates = {
+    "1": 3,
+    "2": 2,
+    "3": 1,
+  };
+  class MockProvider implements Provider {
+    getBlockHeight = () => Promise.resolve(1001);
+    getBlockHash = () => Promise.resolve("hash1001");
+    getFeeEstimates = () => Promise.resolve(feeEstimates);
+    getAllData = () =>
+      Promise.resolve({
+        blockHeight: 1001,
+        blockHash: "hash1001",
+        feeEstimates,
+      });
+  }
+
+  const maxHeightDelta = 1;
+  const feeMultiplier = 1;
+  const feeMinimum = 2;
+  const manager = new DataProviderManager(
+    { stdTTL: 0, checkperiod: 0 },
+    maxHeightDelta,
+    feeMultiplier,
+    feeMinimum,
+  );
+  manager.registerProvider(new MockProvider());
+
+  const mergedData = await manager.getData();
+  expect(mergedData.fee_by_block_target).toEqual({
+    "1": 3000,
+    "2": 2000,
+  });
+});
+
+test("should return single estimate at fee minimum if no valid estimates are available", async () => {
+  const feeEstimates = {
+    "1": 1,
+    "2": 1,
+    "3": 1,
+  };
+  class MockProvider implements Provider {
+    getBlockHeight = () => Promise.resolve(1001);
+    getBlockHash = () => Promise.resolve("hash1001");
+    getFeeEstimates = () => Promise.resolve(feeEstimates);
+    getAllData = () =>
+      Promise.resolve({
+        blockHeight: 1001,
+        blockHash: "hash1001",
+        feeEstimates,
+      });
+  }
+
+  const maxHeightDelta = 1;
+  const feeMultiplier = 1;
+  const feeMinimum = 2;
+  const manager = new DataProviderManager(
+    { stdTTL: 0, checkperiod: 0 },
+    maxHeightDelta,
+    feeMultiplier,
+    feeMinimum,
+  );
+  manager.registerProvider(new MockProvider());
+
+  const mergedData = await manager.getData();
+  expect(mergedData.fee_by_block_target).toEqual({
+    "1": 2000,
+  });
+});