我刚从官方流程网站上复制了一个例子：
// @flow
function doSomething<T>(param: T): T {
// ...
return param;
}
doSomething<number>(3);
并得到错误：
未捕获的ReferenceError：未定义数字
虽然以下代码有效：
function abc(a: number) {
console.log(a);
}
第一个片段有什么问题？
"flow-bin": "^0.92.1",
"flow-runtime": "^0.17.0",
"flow-typed": "^2.4.0"
我用npm run dev运行应用程序
这是一个完整的package.json
{
"name": "myapp",
"productName": "ElectronReact",
"version": "0.13.2",
"description": "Electron application boilerplate based on React, React Router, Webpack, React Hot Loader for rapid application development",
"scripts": {
"build": "concurrently \"npm run build-main\" \"npm run build-renderer\"",
"build-dll": "cross-env NODE_ENV=development node --trace-warnings -r babel-register ./node_modules/webpack/bin/webpack --config webpack.config.renderer.dev.dll.js --colors",
"build-main": "cross-env NODE_ENV=production node --trace-warnings -r babel-register ./node_modules/webpack/bin/webpack --config webpack.config.main.prod.js --colors",
"build-renderer": "cross-env NODE_ENV=production node --trace-warnings -r babel-register ./node_modules/webpack/bin/webpack --config webpack.config.renderer.prod.js --colors",
"dev": "cross-env START_HOT=1 node -r babel-register ./internals/scripts/CheckPortInUse.js && cross-env START_HOT=1 npm run start-renderer-dev",
"electron-rebuild": "electron-rebuild --parallel --force --types prod,dev,optional --module-dir app",
"flow": "flow",
"flow-typed": "rimraf flow-typed/npm && flow-typed install --overwrite || true",
"lint": "cross-env NODE_ENV=development eslint --cache --format=node_modules/eslint-formatter-pretty .",
"lint-fix": "npm run lint -- --fix",
"lint-styles": "stylelint app/*.css app/components/*.css --syntax scss",
"lint-styles-fix": "stylefmt -r app/*.css app/components/*.css",
"package": "npm run build && build --publish never",
"package-all": "npm run build && build -mwl",
"package-linux": "npm run build && build --linux",
"package-win": "npm run build && build --win --x64",
"postinstall": "node -r babel-register internals/scripts/CheckNativeDep.js && npm run flow-typed && npm run build-dll && electron-builder install-app-deps && node node_modules/fbjs-scripts/node/check-dev-engines.js package.json",
"prestart": "npm run build",
"start": "cross-env NODE_ENV=production electron ./app/",
"start-main-dev": "cross-env HOT=1 NODE_ENV=development electron -r babel-register ./app/main.dev",
"start-renderer-dev": "cross-env NODE_ENV=development node --trace-warnings -r babel-register ./node_modules/webpack-dev-server/bin/webpack-dev-server --config webpack.config.renderer.dev.js",
"test": "cross-env NODE_ENV=test BABEL_DISABLE_CACHE=1 node --trace-warnings -r babel-register ./internals/scripts/RunTests.js",
"test-all": "npm run lint && npm run flow && npm run build && npm run test && npm run test-e2e",
"test-e2e": "cross-env NODE_ENV=test BABEL_DISABLE_CACHE=1 node --trace-warnings -r babel-register ./internals/scripts/RunTests.js e2e",
"test-watch": "npm test -- --watch"
},
"browserslist": "electron 1.6",
"build": {
"productName": "ElectronReact",
"appId": "org.develar.ElectronReact",
"files": [
"dist/",
"node_modules/",
"app.html",
"main.prod.js",
"main.prod.js.map",
"package.json"
],
"dmg": {
"contents": [
{
"x": 130,
"y": 220
},
{
"x": 410,
"y": 220,
"type": "link",
"path": "/Applications"
}
]
},
"win": {
"target": [
"nsis"
]
},
"linux": {
"target": [
"deb",
"AppImage"
],
"category": "Development"
},
"directories": {
"buildResources": "resources",
"output": "release"
}
},
"repository": {
"type": "git",
"url": "git+https://github.com/chentsulin/electron-react-boilerplate.git"
},
"author": {
"name": "C. T. Lin",
"email": "[email protected]",
"url": "https://github.com/chentsulin"
},
"license": "MIT",
"bugs": {
"url": "https://github.com/chentsulin/electron-react-boilerplate/issues"
},
"keywords": [
"electron",
"boilerplate",
"react",
"redux",
"flow",
"sass",
"webpack",
"hot",
"reload"
],
"homepage": "https://github.com/chentsulin/electron-react-boilerplate#readme",
"jest": {
"moduleNameMapper": {
"\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/internals/mocks/fileMock.js",
"\\.(css|less|sass|scss)$": "identity-obj-proxy"
},
"moduleFileExtensions": [
"js"
],
"moduleDirectories": [
"node_modules",
"app/node_modules"
],
"transform": {
"^.+\\.js$": "babel-jest"
},
"setupFiles": [
"./internals/scripts/CheckBuiltsExist.js"
]
},
"devDependencies": {
"babel-core": "^6.26.0",
"babel-eslint": "^8.2.1",
"babel-jest": "^22.1.0",
"babel-loader": "^7.1.2",
"babel-plugin-add-module-exports": "^0.2.1",
"babel-plugin-dev-expression": "^0.2.1",
"babel-plugin-flow-runtime": "^0.18.0",
"babel-plugin-transform-class-properties": "^6.24.1",
"babel-plugin-transform-es2015-classes": "^6.24.1",
"babel-preset-env": "^1.6.1",
"babel-preset-react": "^6.24.1",
"babel-preset-react-hmre": "^1.1.1",
"babel-preset-react-optimize": "^1.0.1",
"babel-preset-stage-0": "^6.24.1",
"babel-register": "^6.26.0",
"chalk": "^2.3.0",
"concurrently": "^3.5.1",
"cross-env": "^5.1.3",
"cross-spawn": "^6.0.4",
"css-loader": "^0.28.9",
"detect-port": "^1.2.2",
"electron": "^1.7.11",
"electron-builder": "^19.55.3",
"electron-devtools-installer": "^2.2.3",
"electron-rebuild": "^1.7.3",
"enzyme": "^3.3.0",
"enzyme-adapter-react-16": "^1.1.1",
"enzyme-to-json": "^3.3.1",
"eslint": "^4.16.0",
"eslint-config-airbnb": "^16.1.0",
"eslint-formatter-pretty": "^1.3.0",
"eslint-import-resolver-webpack": "^0.8.4",
"eslint-plugin-compat": "^2.2.0",
"eslint-plugin-flowtype": "^3.2.1",
"eslint-plugin-import": "^2.8.0",
"eslint-plugin-jest": "^21.7.0",
"eslint-plugin-jsx-a11y": "6.0.3",
"eslint-plugin-promise": "^3.6.0",
"eslint-plugin-react": "^7.6.1",
"express": "^4.16.2",
"extract-text-webpack-plugin": "^3.0.2",
"fbjs-scripts": "^0.8.1",
"file-loader": "^1.1.6",
"flow-bin": "^0.92.1",
"flow-runtime": "^0.17.0",
"flow-typed": "^2.4.0",
"identity-obj-proxy": "^3.0.0",
"jest": "^22.1.4",
"minimist": "^1.2.0",
"node-sass": "^4.7.2",
"npm-logical-tree": "^1.2.1",
"react-test-renderer": "^16.2.0",
"redux-logger": "^3.0.6",
"rimraf": "^2.6.2",
"sass-loader": "^6.0.6",
"sinon": "^4.2.2",
"spectron": "^3.8.0",
"style-loader": "^0.20.1",
"stylefmt": "^6.0.0",
"stylelint": "^8.4.0",
"stylelint-config-standard": "^18.0.0",
"uglifyjs-webpack-plugin": "1.1.8",
"url-loader": "^0.6.2",
"webpack": "^3.10.0",
"webpack-bundle-analyzer": "^2.9.2",
"webpack-dev-server": "^2.11.1",
"webpack-merge": "^4.1.1"
},
"dependencies": {
"axios": "^0.18.0",
"bootstrap": "^4.0.0",
"devtron": "^1.4.0",
"electron-debug": "^1.5.0",
"font-awesome": "^4.7.0",
"history": "^4.7.2",
"immutable": "^3.8.2",
"jquery": "^3.3.1",
"normalizr": "^3.2.4",
"popper.js": "^1.14.3",
"react": "^16.7.0",
"react-alert-template-basic": "^1.0.0",
"react-dom": "^16.7.0",
"react-hot-loader": "^4.0.0-beta.13",
"react-notification-system": "^0.2.17",
"react-redux": "^5.0.6",
"react-router": "^4.2.0",
"react-router-dom": "^4.2.2",
"react-router-redux": "^5.0.0-alpha.6",
"react-tooltip": "^3.6.1",
"react-transition-group": "^2.3.1",
"reactstrap": "^7.1.0",
"redux": "^3.7.2",
"redux-form": "^7.3.0",
"redux-form-input-masks": "^1.1.4",
"redux-persist": "^5.10.0",
"redux-saga": "^0.16.2",
"source-map-support": "^0.5.3"
},
"devEngines": {
"node": ">=7.x",
"npm": ">=4.x",
"yarn": ">=0.21.3"
}
}
.flowconfig
[ignore]
<PROJECT_ROOT>/node_modules/*
<PROJECT_ROOT>/app/main.prod.js
<PROJECT_ROOT>/app/main.prod.js.map
<PROJECT_ROOT>/app/dist/.*
<PROJECT_ROOT>/resources/.*
<PROJECT_ROOT>/release/.*
<PROJECT_ROOT>/dll/.*
<PROJECT_ROOT>/release/.*
<PROJECT_ROOT>/git/.*
[include]
[libs]
[options]
esproposal.class_static_fields=enable
esproposal.class_instance_fields=enable
esproposal.export_star_as=enable
module.name_mapper.extension='css' -> '<PROJECT_ROOT>/internals/flow/CSSModule.js.flow'
module.name_mapper.extension='styl' -> '<PROJECT_ROOT>/internals/flow/CSSModule.js.flow'
module.name_mapper.extension='scss' -> '<PROJECT_ROOT>/internals/flow/CSSModule.js.flow'
module.name_mapper.extension='png' -> '<PROJECT_ROOT>/internals/flow/WebpackAsset.js.flow'
module.name_mapper.extension='jpg' -> '<PROJECT_ROOT>/internals/flow/WebpackAsset.js.flow'
suppress_comment=\\(.\\|\n\\)*\\$FlowFixMe
suppress_comment=\\(.\\|\n\\)*\\$FlowIssue
显式类型参数（如<number>）仅在Babel 7中可用。您的代码正在执行为doSomething < number