我正在关注 Lynda.com 的教程“部署全栈反应应用程序”。我正在使用'create-react-app 项目来搭建我的项目。由于某些未知原因，我的应用程序无法访问 api，我可以直接访问该 api，而不会在浏览器上出现任何问题。这是我的 package.json 文件，每当我运行“yarn start”时都会出现错误。
{
"name": "tictacturing",
"version": "0.1.0",
"private": true,
"dependencies": {
"autoprefixer": "7.1.6",
"babel-core": "6.26.0",
"babel-eslint": "7.2.3",
"babel-jest": "20.0.3",
"babel-loader": "7.1.2",
"babel-preset-react-app": "^3.1.0",
"babel-runtime": "6.26.0",
"case-sensitive-paths-webpack-plugin": "2.1.1",
"chalk": "1.1.3",
"css-loader": "0.28.7",
"dotenv": "4.0.0",
"eslint": "4.10.0",
"eslint-config-react-app": "^2.0.1",
"eslint-loader": "1.9.0",
"eslint-plugin-flowtype": "2.39.1",
"eslint-plugin-import": "2.8.0",
"eslint-plugin-jsx-a11y": "5.1.1",
"eslint-plugin-react": "7.4.0",
"extract-text-webpack-plugin": "3.0.2",
"file-loader": "1.1.5",
"fs-extra": "3.0.1",
"html-webpack-plugin": "2.29.0",
"jest": "20.0.4",
"object-assign": "4.1.1",
"postcss-flexbugs-fixes": "3.2.0",
"postcss-loader": "2.0.8",
"promise": "8.0.1",
"raf": "3.4.0",
"react": "^16.2.0",
"react-dev-utils": "^4.2.1",
"react-dom": "^16.2.0",
"react-relay": "^1.4.1",
"relay-runtime": "^1.4.1",
"style-loader": "0.19.0",
"sw-precache-webpack-plugin": "0.11.4",
"url-loader": "0.6.2",
"webpack": "3.8.1",
"webpack-dev-server": "2.9.4",
"webpack-manifest-plugin": "1.3.2",
"whatwg-fetch": "2.0.3"
},
"scripts": {
"start": "set GRAPHQL_ENDPOINT=https://api.graph.cool/relay/v1/cjazdk3jg0yj70197193cltrf && node scripts/start.js",
"build": "set GRAPHQL_ENDPOINT=https://api.graph.cool/relay/v1/cjazdk3jg0yj70197193cltrf && node scripts/build.js",
"test": "node scripts/test.js --env=jsdom"
},
"jest": {
"collectCoverageFrom": [
"src/**/*.{js,jsx,mjs}"
],
"setupFiles": [
"<rootDir>/config/polyfills.js"
],
"testMatch": [
"<rootDir>/src/**/__tests__/**/*.{js,jsx,mjs}",
"<rootDir>/src/**/?(*.)(spec|test).{js,jsx,mjs}"
],
"testEnvironment": "node",
"testURL": "http://localhost",
"transform": {
"^.+\\.(js|jsx|mjs)$": "<rootDir>/node_modules/babel-jest",
"^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
"^(?!.*\\.(js|jsx|mjs|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
},
"transformIgnorePatterns": [
"[/\\\\]node_modules[/\\\\].+\\.(js|jsx|mjs)$"
],
"moduleNameMapper": {
"^react-native$": "react-native-web"
},
"moduleFileExtensions": [
"web.js",
"mjs",
"js",
"json",
"web.jsx",
"jsx",
"node"
]
},
"babel": {
"plugins": [
"react-relay"
],
"presets": [
"react-app"
]
},
"eslintConfig": {
"extends": "react-app"
},
"devDependencies": {
"babel-plugin-react-relay": "^0.10.0",
"eslint": "^4.10.0",
"eslint-plugin-react": "^7.4.0"
}
}