In the past months I have been developing a React web application that is displayed within a ASP.NET Core web project (template of Visual Studio). The application has worked in recent months and is used by users who will display it exclusively in IE 11 (Office web add-in that uses IE 11 rendering engine). I have used the 'fetch' method extensively and did not experience problems after adding the babel-polyfill npm package. Unfortunately, today I received the following error:
'fetch' is undefined
The polyfill packages are still present and I am unclear as to why this error is reported suddenly. As stated above it did work before, and I am unsure what caused the situation in which the 'isomorphic-fetch' package stopped working. Below you will find the package.json contents. Any insight into where to look for the root cause of this problem would be greatly appreciated!
{
"name": "ReactApp",
"private": true,
"version": "0.0.0",
"devDependencies": {
"@types/history": "4.6.0",
"@types/react": "15.0.38",
"@types/react-dom": "15.5.1",
"@types/react-hot-loader": "3.0.3",
"@types/react-router": "4.0.12",
"@types/react-router-dom": "4.0.5",
"@types/webpack-env": "1.13.0",
"aspnet-webpack": "^2.0.1",
"aspnet-webpack-react": "^3.0.0",
"awesome-typescript-loader": "3.2.1",
"bootstrap": "3.3.7",
"css-loader": "0.28.4",
"event-source-polyfill": "0.0.9",
"extract-text-webpack-plugin": "2.1.2",
"file-loader": "0.11.2",
"isomorphic-fetch": "2.2.1",
"jquery": "3.2.1",
"json-loader": "0.5.4",
"react": "15.6.1",
"react-dom": "15.6.1",
"react-hot-loader": "3.0.0-beta.7",
"react-router-dom": "4.1.1",
"style-loader": "0.18.2",
"typescript": "2.4.1",
"url-loader": "0.5.9",
"webpack": "2.5.1",
"webpack-hot-middleware": "2.18.2"
},
"dependencies": {
"@microsoft/office-js": "^1.1.2",
"@types/prop-types": "^15.5.2",
"babel-polyfill": "^6.26.0",
"moment": "^2.20.1",
"office-ui-fabric-core": "^9.3.0",
"office-ui-fabric-react": "https://registry.npmjs.org/office-ui-fabric-react/-/office-ui-fabric-react-5.29.0.tgz"
}
}