From 40888c405db19f1860f0d3f22e26cc5dc541306f Mon Sep 17 00:00:00 2001
From: nicholaspai <9457025+nicholaspai@users.noreply.github.com>
Date: Thu, 9 Jan 2025 09:20:19 -0500
Subject: [PATCH] feat(GasPriceAdapter): Allow caller to set a minimum priority
 fee for eip1559Raw adapter (#821)

---
 package.json                            |  2 +-
 src/gasPriceOracle/adapters/ethereum.ts |  8 +++-
 test/GasPriceOracle.test.ts             | 57 +++++++++++++++++++++++++
 3 files changed, 64 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index ab2093e9..7428d47e 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@across-protocol/sdk",
   "author": "UMA Team",
-  "version": "3.4.6",
+  "version": "3.4.7",
   "license": "AGPL-3.0",
   "homepage": "https://docs.across.to/reference/sdk",
   "files": [
diff --git a/src/gasPriceOracle/adapters/ethereum.ts b/src/gasPriceOracle/adapters/ethereum.ts
index 4de4f39a..3c8fbca1 100644
--- a/src/gasPriceOracle/adapters/ethereum.ts
+++ b/src/gasPriceOracle/adapters/ethereum.ts
@@ -1,6 +1,6 @@
 import assert from "assert";
 import { providers } from "ethers";
-import { BigNumber, bnZero, fixedPointAdjustment, getNetworkName } from "../../utils";
+import { BigNumber, bnZero, fixedPointAdjustment, getNetworkName, parseUnits } from "../../utils";
 import { GasPriceEstimate } from "../types";
 import { gasPriceError } from "../util";
 import { GasPriceEstimateOptions } from "../oracle";
@@ -43,7 +43,11 @@ export async function eip1559Raw(
     provider.getBlock("pending"),
     (provider as providers.JsonRpcProvider).send("eth_maxPriorityFeePerGas", []),
   ]);
-  const maxPriorityFeePerGas = BigNumber.from(_maxPriorityFeePerGas);
+  let maxPriorityFeePerGas = BigNumber.from(_maxPriorityFeePerGas);
+  const flooredPriorityFeePerGas = parseUnits(process.env[`MIN_PRIORITY_FEE_PER_GAS_${chainId}`] || "0", 9);
+  if (maxPriorityFeePerGas.lt(flooredPriorityFeePerGas)) {
+    maxPriorityFeePerGas = BigNumber.from(flooredPriorityFeePerGas);
+  }
   assert(BigNumber.isBigNumber(baseFeePerGas), `No baseFeePerGas received on ${getNetworkName(chainId)}`);
 
   const scaledPriorityFee = maxPriorityFeePerGas.mul(priorityFeeMultiplier).div(fixedPointAdjustment);
diff --git a/test/GasPriceOracle.test.ts b/test/GasPriceOracle.test.ts
index 4f33d365..e5c06510 100644
--- a/test/GasPriceOracle.test.ts
+++ b/test/GasPriceOracle.test.ts
@@ -182,6 +182,63 @@ describe("Gas Price Oracle", function () {
     expect(markedUpMaxPriorityFeePerGas).to.equal(expectedMarkedUpPriorityFee);
     delete process.env[chainKey];
   });
+  it("Ethers EIP1559 Raw: min priority fee is respected", async function () {
+    const baseFeeMultiplier = toBNWei("2.0");
+    const priorityFeeMultiplier = toBNWei("1.5");
+    const minPriorityFeeScaler = "1.5";
+    const minPriorityFee = parseUnits(minPriorityFeeScaler, 9);
+    const chainId = 1;
+    const chainKey = `GAS_PRICE_EIP1559_RAW_${chainId}`;
+    const minPriorityFeeKey = `MIN_PRIORITY_FEE_PER_GAS_${chainId}`;
+    process.env[chainKey] = "true";
+    process.env[minPriorityFeeKey] = minPriorityFeeScaler;
+
+    const { maxFeePerGas: markedUpMaxFeePerGas, maxPriorityFeePerGas: markedUpMaxPriorityFeePerGas } =
+      await getGasPriceEstimate(provider, { chainId, baseFeeMultiplier, priorityFeeMultiplier });
+
+    // Base fee should be multiplied by multiplier. Returned max fee includes priority fee
+    // so back it out before scaling.
+    const expectedMarkedUpPriorityFee = minPriorityFee.mul(priorityFeeMultiplier).div(fixedPointAdjustment);
+    const expectedMarkedUpMaxFeePerGas = stdLastBaseFeePerGas
+      .mul(baseFeeMultiplier)
+      .div(fixedPointAdjustment)
+      .add(expectedMarkedUpPriorityFee);
+    expect(markedUpMaxFeePerGas).to.equal(expectedMarkedUpMaxFeePerGas);
+
+    // Priority fees should be scaled.
+    expect(markedUpMaxPriorityFeePerGas).to.equal(expectedMarkedUpPriorityFee);
+    delete process.env[chainKey];
+    delete process.env[minPriorityFeeKey];
+  });
+  it("Ethers EIP1559 Raw: min priority fee is ignored", async function () {
+    const baseFeeMultiplier = toBNWei("2.0");
+    const priorityFeeMultiplier = toBNWei("1.5");
+    const minPriorityFeeScaler = "0.5";
+    const minPriorityFee = parseUnits(minPriorityFeeScaler, 9);
+    expect(minPriorityFee.lt(stdMaxPriorityFeePerGas)).to.be.true;
+    const chainId = 1;
+    const chainKey = `GAS_PRICE_EIP1559_RAW_${chainId}`;
+    const minPriorityFeeKey = `MIN_PRIORITY_FEE_PER_GAS_${chainId}`;
+    process.env[chainKey] = "true";
+    process.env[minPriorityFeeKey] = minPriorityFeeScaler.toString();
+
+    const { maxFeePerGas: markedUpMaxFeePerGas, maxPriorityFeePerGas: markedUpMaxPriorityFeePerGas } =
+      await getGasPriceEstimate(provider, { chainId, baseFeeMultiplier, priorityFeeMultiplier });
+
+    // Base fee should be multiplied by multiplier. Returned max fee includes priority fee
+    // so back it out before scaling.
+    const expectedMarkedUpPriorityFee = stdMaxPriorityFeePerGas.mul(priorityFeeMultiplier).div(fixedPointAdjustment);
+    const expectedMarkedUpMaxFeePerGas = stdLastBaseFeePerGas
+      .mul(baseFeeMultiplier)
+      .div(fixedPointAdjustment)
+      .add(expectedMarkedUpPriorityFee);
+    expect(markedUpMaxFeePerGas).to.equal(expectedMarkedUpMaxFeePerGas);
+
+    // Priority fees should be scaled.
+    expect(markedUpMaxPriorityFeePerGas).to.equal(expectedMarkedUpPriorityFee);
+    delete process.env[chainKey];
+    delete process.env[minPriorityFeeKey];
+  });
   it("Ethers EIP1559 Bad", async function () {
     // This test should return identical results to the Raw test but it makes different
     // provider calls, so we're really testing that the expected provider functions are called.