fix minor comments

packages/gas-fee-controller/src/GasFeeController.ts

@@ -25,10 +25,11 @@ import { v1 as random } from 'uuid';
 import determineGasFeeCalculations from './determineGasFeeCalculations';
 import fetchGasEstimatesViaEthFeeHistory from './fetchGasEstimatesViaEthFeeHistory';
 import {
+  buildInfuraAuthToken,
+  calculateTimeEstimate,
   fetchGasEstimates,
   fetchLegacyGasPriceEstimates,
   fetchEthGasPriceEstimate,
-  calculateTimeEstimate,
 } from './gas-util';
 
 export const GAS_API_BASE_URL = 'https://gas.api.infura.io';
@@ -352,9 +353,10 @@ export class GasFeeController extends StaticIntervalPollingController<
     this.EIP1559APIEndpoint = `${GAS_API_BASE_URL}/networks/<chain_id>/suggestedGasFees`;
     this.legacyAPIEndpoint = `${GAS_API_BASE_URL}/networks/<chain_id>/gasPrices`;
     this.clientId = clientId;
-    this.infuraAuthToken = Buffer.from(
-      `${infuraAPIKey}:${infuraAPIKeySecret}`,
-    ).toString('base64');
+    this.infuraAuthToken = buildInfuraAuthToken(
+      infuraAPIKey,
+      infuraAPIKeySecret,
+    );
 
     this.ethQuery = new EthQuery(this.#getProvider());
 

packages/gas-fee-controller/src/gas-util.test.ts

@@ -91,9 +91,9 @@ describe('gas utils', () => {
 
       expect(handleFetchMock).toHaveBeenCalledTimes(1);
       expect(handleFetchMock).toHaveBeenCalledWith(INFURA_GAS_API_URL_MOCK, {
-        headers: {
+        headers: expect.objectContaining({
           Authorization: `Basic ${INFURA_AUTH_TOKEN_MOCK}`,
-        },
+        }),
       });
       expect(result).toMatchObject(mockEIP1559ApiResponses[0]);
     });
@@ -109,10 +109,10 @@ describe('gas utils', () => {
 
       expect(handleFetchMock).toHaveBeenCalledTimes(1);
       expect(handleFetchMock).toHaveBeenCalledWith(INFURA_GAS_API_URL_MOCK, {
-        headers: {
+        headers: expect.objectContaining({
           Authorization: `Basic ${INFURA_AUTH_TOKEN_MOCK}`,
           'X-Client-Id': clientIdMock,
-        },
+        }),
       });
       expect(result).toMatchObject(mockEIP1559ApiResponses[0]);
     });

packages/gas-fee-controller/src/gas-util.ts

@@ -43,11 +43,7 @@ export async function fetchGasEstimates(
   clientId?: string,
 ): Promise<GasFeeEstimates> {
   const estimates = await handleFetch(url, {
-    headers: {
-      Authorization: `Basic ${infuraAuthToken}`,
-      // Only add the clientId header if clientId is a non-empty string
-      ...(clientId?.trim() ? makeClientIdHeader(clientId) : {}),
-    },
+    headers: getHeaders(infuraAuthToken, clientId),
   });
   return {
     low: {
@@ -106,12 +102,7 @@ export async function fetchLegacyGasPriceEstimates(
     referrerPolicy: 'no-referrer-when-downgrade',
     method: 'GET',
     mode: 'cors',
-    headers: {
-      'Content-Type': 'application/json',
-      Authorization: `Basic ${infuraAuthToken}`,
-      // Only add the clientId header if clientId is a non-empty string
-      ...(clientId?.trim() ? makeClientIdHeader(clientId) : {}),
-    },
+    headers: getHeaders(infuraAuthToken, clientId),
   });
   return {
     low: result.SafeGasPrice,
@@ -200,3 +191,35 @@ export function calculateTimeEstimate(
     upperTimeBound,
   };
 }
+
+/**
+ * Build an infura auth token from the given API key and secret.
+ *
+ * @param infuraAPIKey - The Infura API key.
+ * @param infuraAPIKeySecret - The Infura API key secret.
+ * @returns The base64 encoded auth token.
+ */
+export function buildInfuraAuthToken(
+  infuraAPIKey: string,
+  infuraAPIKeySecret: string,
+) {
+  return Buffer.from(`${infuraAPIKey}:${infuraAPIKeySecret}`).toString(
+    'base64',
+  );
+}
+
+/**
+ * Get the headers for a request to the gas fee API.
+ *
+ * @param infuraAuthToken - The Infura auth token to use for the request.
+ * @param clientId - The client ID used to identify to the API who is asking for estimates.
+ * @returns The headers for the request.
+ */
+function getHeaders(infuraAuthToken: string, clientId?: string) {
+  return {
+    'Content-Type': 'application/json',
+    Authorization: `Basic ${infuraAuthToken}`,
+    // Only add the clientId header if clientId is a non-empty string
+    ...(clientId?.trim() ? makeClientIdHeader(clientId) : {}),
+  };
+}