Support webpack with node environments (e.g. electron)

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        bundler: [browserify, webpack]
+        bundler: [browserify, webpack, "webpack:node"]
     steps:
     - name: checkout
       uses: actions/checkout@master

fetch-node.js

@@ -15,17 +15,20 @@ function wrapFetchForNode(fetch) {
 }
 
 module.exports = function (context) {
+  // Support webpack module import weirdness.
+  var fetchFn = fetch.default ? fetch.default : fetch;
+
   // This modifies the global `node-fetch` object, which isn't great, since
   // different callers to `fetch-ponyfill` which pass a different Promise
   // implementation would each expect to have their implementation used. But,
   // given the way `node-fetch` is implemented, this is the only way to make
   // it work at all.
   if (context && context.Promise) {
-    fetch.Promise = context.Promise;
+    fetchFn.Promise = context.Promise;
   }
 
   return {
-    fetch: wrapFetchForNode(fetch),
+    fetch: wrapFetchForNode(fetchFn),
     Headers: fetch.Headers,
     Request: fetch.Request,
     Response: fetch.Response

package.json

@@ -15,6 +15,8 @@
     "test:browserify": "testem ci",
     "pretest:webpack": "npm run build && webpack --mode development tests/fetch-browser.spec.js -o build/browser-test-bundle.js",
     "test:webpack": "testem ci",
+    "pretest:webpack:node": "webpack --mode development --target node tests/fetch-node.spec.js -o build/node-test-bundle.js",
+    "test:webpack:node": "mocha build/node-test-bundle.js",
     "build": "rimraf build && mkdirp build && node build.js > build/fetch-browser.js",
     "prepublishOnly": "npm run build"
   },