Move DEFAULT_UPLINK_ENDPOINTS to static member (#1977)

* Move DEFAULT_UPLINK_ENDPOINTS to static member

This helps reduce the API surface and keeps data scoped to the manager

gateway-js/CHANGELOG.md

@@ -15,6 +15,7 @@ This CHANGELOG pertains only to Apollo Federation packages in the 2.x range. The
   - __BREAKING__: previously, directive applications within a `@key`, `@provides` or `@requires` were parsed but
     not honored in any way. As this change reject such applications (at composition time), it could theoretically
     require to remove some existing (ignored) directive applications within a `@key`, `@provides` or `@requires`.
+- Move `DEFAULT_UPLINK_ENDPOINTS` to static member of `UplinkSupergraphManager` [PR #1977](https://github.com/apollographql/federation/pull/1977).
 
 ## 2.1.0-alpha.0
 

gateway-js/src/index.ts

@@ -1079,5 +1079,4 @@ export {
   FailureToFetchSupergraphSdlAfterInit,
   FailureToFetchSupergraphSdlDuringInit,
   FailureToFetchSupergraphSdlFunctionParams,
-  DEFAULT_UPLINK_ENDPOINTS,
 } from './supergraphManagers';

gateway-js/src/supergraphManagers/UplinkSupergraphManager/__tests__/UplinkSupergraphManager.test.ts

@@ -2,8 +2,6 @@ import mockedEnv from 'mocked-env';
 
 import { UplinkSupergraphManager } from '@apollo/gateway';
 
-import { DEFAULT_UPLINK_ENDPOINTS } from '..';
-
 let cleanUp: (() => void) | undefined;
 
 const logger = {
@@ -31,7 +29,7 @@ describe('UplinkSupergraphManager', () => {
     it('uses default uplink URLs', async () => {
       const manager = new UplinkSupergraphManager({ apiKey, graphRef, logger });
 
-      expect(manager.uplinkEndpoints).toEqual(DEFAULT_UPLINK_ENDPOINTS);
+      expect(manager.uplinkEndpoints).toEqual(UplinkSupergraphManager.DEFAULT_UPLINK_ENDPOINTS);
     });
 
     it('can set uplink URLs via config', async () => {

gateway-js/src/supergraphManagers/UplinkSupergraphManager/index.ts

@@ -10,22 +10,6 @@ import { getDefaultLogger } from '../../logger';
 import { loadSupergraphSdlFromUplinks } from './loadSupergraphSdlFromStorage';
 import { Fetcher } from '@apollo/utils.fetcher';
 
-export const DEFAULT_UPLINK_ENDPOINTS = [
-  'https://uplink.api.apollographql.com/',
-  'https://aws.uplink.api.apollographql.com/',
-];
-
-function getUplinkEndpoints(): string[] {
-  /**
-   * Configuration priority order:
-   * 1. APOLLO_SCHEMA_CONFIG_DELIVERY_ENDPOINT environment variable
-   * 2. default (GCP and AWS)
-   */
-  const envEndpoints =
-    process.env.APOLLO_SCHEMA_CONFIG_DELIVERY_ENDPOINT?.split(',');
-  return envEndpoints ?? DEFAULT_UPLINK_ENDPOINTS;
-}
-
 export type FailureToFetchSupergraphSdlFunctionParams = {
   error: Error;
   graphRef: string;
@@ -61,7 +45,13 @@ type State =
   | { phase: 'stopped' };
 
 export class UplinkSupergraphManager implements SupergraphManager {
-  public readonly uplinkEndpoints: string[] = getUplinkEndpoints();
+  public static readonly DEFAULT_UPLINK_ENDPOINTS = [
+    'https://uplink.api.apollographql.com/',
+    'https://aws.uplink.api.apollographql.com/',
+  ];
+
+  public readonly uplinkEndpoints: string[] =
+    UplinkSupergraphManager.getUplinkEndpoints();
   private apiKey: string;
   private graphRef: string;
   private fetcher: Fetcher = makeFetchHappen.defaults();
@@ -187,6 +177,17 @@ export class UplinkSupergraphManager implements SupergraphManager {
     return this.state.nextFetchPromise;
   }
 
+  /**
+   * Configuration priority order:
+   * 1. APOLLO_SCHEMA_CONFIG_DELIVERY_ENDPOINT environment variable
+   * 2. default (GCP and AWS)
+   */
+  public static getUplinkEndpoints(): string[] {
+    const envEndpoints =
+      process.env.APOLLO_SCHEMA_CONFIG_DELIVERY_ENDPOINT?.split(',');
+    return envEndpoints ?? UplinkSupergraphManager.DEFAULT_UPLINK_ENDPOINTS;
+  }
+
   private async updateSupergraphSdl(maxRetries: number): Promise<{
     supergraphSdl: string;
     minDelaySeconds: number;