PropTypes 在 React 中不起作用

Question

I am running React 16.2.0 and I am using PropTypes 15.6.1. I am using ES6 syntax and Webpack.

I am trying to make PropTypes throw a warning when I pass invalid props, but it doesn't work. This is the code:

SimpleMessage.js

import React from "react"
import PropTypes from "prop-types"

class SimpleMessage extends React.Component {
    render() {
        return(
            <p>{this.props.message}</p>
        )
    }
}

SimpleMessage.propTypes = {
    message: PropTypes.func
}

export default SimpleMessage

index.js

import React from "react"
import ReactDOM from "react-dom"

import SimpleMessage from "./components/SimpleMessage"

window.React = React

ReactDOM.render(
    <SimpleMessage message={"Hello World"} />,
    document.getElementById("react-container")
)

webpack.config.js

var webpack = require("webpack")
var path = require("path")

process.noDeprecation = true

module.exports = {
    entry: "./src/index.js",
    output: {
        path: path.join(__dirname, 'dist', 'assets'),
        filename: "bundle.js",
        sourceMapFilename: 'bundle.map'
    },
    devtool: '#source-map',
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /(node_modules)/,
                loader: 'babel-loader',
                query: {
                    presets: ['env', 'stage-0', 'react']
                }
            },
            {
                test: /\.css$/,
                use: ['style-loader','css-loader', {
                    loader: 'postcss-loader',
                    options: {
                      plugins: () => [require('autoprefixer')]
                    }}]
            },
            {
                test: /\.scss/,
                use: ['style-loader','css-loader', {
                    loader: 'postcss-loader',
                    options: {
                      plugins: () => [require('autoprefixer')]
                    }}, 'sass-loader']
            }
        ]
    },
    plugins: [
        new webpack.DefinePlugin({
            "process.env": {
                NODE_ENV: JSON.stringify("production")
            }
        }),
        new webpack.optimize.UglifyJsPlugin({
            sourceMap: true,
            warnings: false,
            mangle: false
        })
    ]

}

As you might notice I am passing a string ("Hello World") but checking for a function in proptypes. I don't get any errors or warnings by proptypes, and the code runs just fine.

Answer 1

Working as expected :

Warning: Failed prop type: Invalid prop message of type string supplied to SimpleMessage , expected function .

Be sure to check your browser console, this is where errors are displayed.

https://codepen.io/anon/pen/paGYjm?editors=1111

---

Also :

You shouldn't apply UglifyJsPlugin or DefinePlugin with 'production' value in development because they will hide useful React warnings, and make the builds much slower.

source

Answer 2

That's because you've defined propType as function , but you're sending it as a string .

Change the code to message: PropTypes.string