fall back to node-fetch only if native fetch is unsupported (#679)

Author: silesky

packages/node/src/__tests__/graceful-shutdown-integration.test.ts

@@ -1,7 +1,7 @@
 import { createSuccess } from './test-helpers/factories'
 
 const fetcher = jest.fn()
-jest.mock('node-fetch', () => fetcher)
+jest.mock('../lib/fetch', () => fetcher)
 
 import { Analytics, SegmentEvent } from '../app/analytics-node'
 import { sleep } from './test-helpers/sleep'

packages/node/src/__tests__/http-integration.test.ts

@@ -1,5 +1,5 @@
 const fetcher = jest.fn()
-jest.mock('node-fetch', () => fetcher)
+jest.mock('../lib/fetch', () => fetcher)
 
 import { createSuccess } from './test-helpers/factories'
 import { Analytics } from '..'

packages/node/src/__tests__/integration.test.ts

@@ -1,5 +1,5 @@
 const fetcher = jest.fn()
-jest.mock('node-fetch', () => fetcher)
+jest.mock('../lib/fetch', () => fetcher)
 
 import { Analytics } from '../index'
 import { CorePlugin as Plugin } from '@segment/analytics-core'

packages/node/src/lib/fetch.ts

@@ -0,0 +1,6 @@
+import { default as nodeFetch } from 'node-fetch'
+
+// made this a default export so it mocks the same as node-fetch in tests.
+const fetch = globalThis.fetch || nodeFetch
+
+export default fetch

packages/node/src/plugins/segmentio/__tests__/index.test.ts

@@ -1,5 +1,5 @@
 const fetcher = jest.fn()
-jest.mock('node-fetch', () => fetcher)
+jest.mock('../../../lib/fetch', () => fetcher)
 
 import { CoreContext } from '@segment/analytics-core'
 import { createNodeEventFactory } from '../../../lib/create-node-event-factory'

packages/node/src/plugins/segmentio/publisher.ts

@@ -1,7 +1,7 @@
 import { backoff, CoreContext } from '@segment/analytics-core'
-import fetch from 'node-fetch'
 import { tryCreateFormattedUrl } from '../../lib/create-url'
 import { extractPromiseParts } from '../../lib/extract-promise-parts'
+import fetch from '../../lib/fetch'
 import { ContextBatch } from './context-batch'
 
 function sleep(timeoutInMs: number): Promise<void> {