“React.createContext is not a function” - but I am not using it

问题

I am getting "React.createContext is not a function" error while running a react-native application. I searched for 'createContent' in the code, it doesn't exist.

Any idea what may be the reason for the error.

It is an iOS build of an app that is already running on android.

Here is my package.json file:

{
  "name": "newapp",
  "version": "0.0.2",
  "private": true,
  "scripts": {
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "test": "jest --verbose --coverage",
    "test:update": "jest --verbose --coverage --updateSnapshot",
    "test:watch": "jest --verbose --watch",
    "coverage": "jest --verbose --coverage && xdg-open ./coverage/lcov-report/index.html",
    "lint": "npx eslint --fix ./src/*"
  },
  "dependencies": {
    "apollo-boost": "0.1.17",
    "axios": "^0.18.0",
    "babel": "^6.23.0",
    "buffer": "5.1.0",
    "cross-fetch": "^3.0.0",
    "enzyme": "^3.3.0",
    "graphql": "0.13.2",
    "graphql-tag": "2.10.0",
    "jasmine-react-helpers": "^0.2.2",
    "lodash": "4.17.5",
    "moment": "2.21.0",
    "query-string": "^6.1.0",
    "react": "16.2.0",
    "react-addons-test-utils": "^15.6.2",
    "react-apollo": "2.2.4",
    "react-dom": "^16.4.0",
    "react-native": "0.51.0",
    "react-native-elements": "0.19.0",
    "react-native-fabric": "^0.5.1",
    "react-native-htmlview": "^0.12.1",
    "react-native-link-preview": "^1.3.5",
    "react-native-login": "^0.0.1-alpha.2",
    "react-native-login-keycloak": "^1.0.2",
    "react-native-onesignal": "3.2.6",
    "react-native-push-notification": "https://github.com/Dhanraj-bidchat/react-native-push-notification.git",
    "react-native-sleek-loading-indicator": "^0.1.3",
    "react-native-spinkit": "^1.1.1",
    "react-native-svg": "6.2.2",
    "react-native-swipe-cards": "^0.1.1",
    "react-native-swiper": "1.5.13",
    "react-native-vector-icons": "4.5.0",
    "react-navigation": "1.5.6",
    "react-redux": "5.0.7",
    "redux": "^3.7.2",
    "redux-logger": "^3.0.6",
    "redux-persist": "5.9.1",
    "redux-thunk": "^2.2.0",
    "victory-native": "0.17.2",
    "whatwg-fetch": "2.0.4"
  },
  "devDependencies": {
    "babel-eslint": "^8.2.3",
    "babel-jest": "^22.4.4",
    "babel-plugin-dynamic-import-node": "^1.2.0",
    "babel-plugin-syntax-dynamic-import": "^6.18.0",
    "babel-plugin-transform-class-properties": "^6.24.1",
    "babel-plugin-transform-es2015-modules-commonjs": "^6.26.2",
    "babel-preset-env": "^1.7.0",
    "babel-preset-react-native": "4.0.0",
    "enzyme-adapter-react-16": "^1.1.1",
    "enzyme-to-json": "^3.3.4",
    "eslint": "^4.19.1",
    "eslint-config-standard": "^11.0.0",
    "eslint-plugin-import": "^2.12.0",
    "eslint-plugin-jest": "^21.17.0",
    "eslint-plugin-node": "^6.0.1",
    "eslint-plugin-only-warn": "^1.0.1",
    "eslint-plugin-promise": "^3.8.0",
    "eslint-plugin-react": "^7.9.1",
    "eslint-plugin-standard": "^3.1.0",
    "jest": "^23.5.0",
    "jest-resolve": "^23.0.0",
    "jest-serializer-enzyme": "^1.0.0",
    "react-native-mock-render": "^0.0.26",
    "react-test-renderer": "^16.3.2",
    "redux-mock-store": "^1.5.1",
    "sinon": "^5.0.10"
  },
  "jest": {
    "preset": "react-native",
    "setupFiles": [
      "./jest-setup.js"
    ],
    "snapshotSerializers": [
      "enzyme-to-json/serializer"
    ],
    "modulePaths": [
      "<rootDir>/src",
      "<rootDir>/node_modules"
    ],
    "transform": {
      "^.+\\.js$": "babel-jest",
      "^.+\\.jsx?$": "babel-jest"
    },
    "transformIgnorePatterns": [
      "node_modules/(?!(react-native-safe-area-view|react-navigation|react-native-htmlview|react-native-fabric|react-native-login|react-native-elements|react-native-vector-icons|react-native-spinkit|victory-pie|victory-chart|victory-core|react-native-svg|react-native|redux-persist|victory-native|react-native-swipe-cards|react-native-swiper)/)"
    ],
    "moduleNameMapper": {
      "\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/assetsTransformer.js",
      "\\.(css|less)$": "<rootDir>/assetsTransformer.js"
    }
  }
}

回答1:

In your package react and react-dom are not having the same version which is why you get the error. react-dom@16.4.0 will want to have access to React.createContext but react@16.2.0 won't have it.

In order make it work run the following command