javascript JSON 中的意外标记 m 在位置 0 错误
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Unexpected token m in JSON at position 0 error
提问by vascobento
On compiling an app and trying to implement the i18n library with webpack, I face this error:
在编译应用程序并尝试使用 webpack 实现 i18n 库时，我遇到了以下错误：
ERROR in ./node_modules/bundle-loader?lazy&name=lang-pt!./src/locales/pt/translation.json
Module parse failed: Unexpected token m in JSON at position 0
You may need an appropriate loader to handle this file type.
SyntaxError: Unexpected token m in JSON at position 0
at JSON.parse (<anonymous>)
at JsonParser.parse (C:\Users\vasco.bento\ContactosWebPack\node_modules\webpack\lib\JsonParser.js:15:21)
at doBuild.err (C:\Users\vasco.bento\ContactosWebPack\node_modules\webpack\lib\NormalModule.js:367:32)
at runLoaders (C:\Users\vasco.bento\ContactosWebPack\node_modules\webpack\lib\NormalModule.js:264:12)
at C:\Users\vasco.bento\ContactosWebPack\node_modules\loader-runner\lib\LoaderRunner.js:370:3
at iterateNormalLoaders (C:\Users\vasco.bento\ContactosWebPack\node_modules\loader-runner\lib\LoaderRunner.js:211:10)
at C:\Users\vasco.bento\ContactosWebPack\node_modules\loader-runner\lib\LoaderRunner.js:183:6
at runSyncOrAsync (C:\Users\vasco.bento\ContactosWebPack\node_modules\loader-runner\lib\LoaderRunner.js:130:11)
at C:\Users\vasco.bento\ContactosWebPack\node_modules\loader-runner\lib\LoaderRunner.js:175:3
at loadLoader (C:\Users\vasco.bento\ContactosWebPack\node_modules\loader-runner\lib\loadLoader.js:36:3)
at iteratePitchingLoaders (C:\Users\vasco.bento\ContactosWebPack\node_modules\loader-runner\lib\LoaderRunner.js:169:2)
at runLoaders (C:\Users\vasco.bento\ContactosWebPack\node_modules\loader-runner\lib\LoaderRunner.js:362:2)
at NormalModule.doBuild (C:\Users\vasco.bento\ContactosWebPack\node_modules\webpack\lib\NormalModule.js:219:3)
at NormalModule.build (C:\Users\vasco.bento\ContactosWebPack\node_modules\webpack\lib\NormalModule.js:337:15)
at Compilation.buildModule (C:\Users\vasco.bento\ContactosWebPack\node_modules\webpack\lib\Compilation.js:346:10)
at factory.create (C:\Users\vasco.bento\ContactosWebPack\node_modules\webpack\lib\Compilation.js:572:15)
@ ./node_modules/aurelia-i18n/dist/native-modules/aurelia-i18n.js
@ ./src/main.js
@ ./node_modules/aurelia-webpack-plugin/runtime/empty-entry.js
@ multi aurelia-webpack-plugin/runtime/empty-entry aurelia-webpack-plugin/runtime/pal-loader-entry aurelia-bootstrapper
ERROR in chunk app [entry]
[name].[hash].bundle.js
Cannot read property 'replace' of undefined
This repeats for the other language I have in the locales folder, which is correctly placed in the src folder, even if the JSON files are completely empty, the same error occurs.
这对我在 locales 文件夹中的其他语言重复，该文件夹正确放置在 src 文件夹中，即使 JSON 文件完全为空，也会发生同样的错误。
Here's the webconfig.js file:
这是 webconfig.js 文件：
const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const project = require('./aurelia_project/aurelia.json');
const {
AureliaPlugin,
ModuleDependenciesPlugin
} = require('aurelia-webpack-plugin');
const {
ProvidePlugin
} = require('webpack');
const {
BundleAnalyzerPlugin
} = require('webpack-bundle-analyzer');
// config helpers:
const ensureArray = (config) => config && (Array.isArray(config) ? config : [config]) || [];
const when = (condition, config, negativeConfig) =>
condition ? ensureArray(config) : ensureArray(negativeConfig);
// primary config:
const title = 'Aurelia Navigation Skeleton';
const outDir = path.resolve(__dirname, project.platform.output);
const srcDir = path.resolve(__dirname, 'src');
const nodeModulesDir = path.resolve(__dirname, 'node_modules');
const baseUrl = '/';
const cssRules = [{
loader: 'css-loader'
}];
module.exports = ({
production,
server,
extractCss,
coverage,
analyze
} = {}) => ({
resolve: {
extensions: ['.js'],
modules: [srcDir, 'node_modules']
},
entry: {
app: ['aurelia-bootstrapper'],
vendor: ['bluebird']
},
mode: production ? 'production' : 'development',
output: {
path: outDir,
publicPath: baseUrl,
filename: production ? '[name].[chunkhash].bundle.js' : '[name].[hash].bundle.js',
sourceMapFilename: production ? '[name].[chunkhash].bundle.map' : '[name].[hash].bundle.map',
chunkFilename: production ? '[name].[chunkhash].chunk.js' : '[name].[hash].chunk.js'
},
performance: {
hints: false
},
devServer: {
contentBase: outDir,
// serve index.html for all 404 (required for push-state)
historyApiFallback: true
},
devtool: production ? 'nosources-source-map' : 'cheap-module-eval-source-map',
module: {
rules: [
// CSS required in JS/TS files should use the style-loader that auto-injects it into the website
// only when the issuer is a .js/.ts file, so the loaders are not applied inside html templates
{
test: /\.css$/i,
issuer: [{
not: [{
test: /\.html$/i
}]
}],
use: extractCss ? ExtractTextPlugin.extract({
fallback: 'style-loader',
use: cssRules
}) : ['style-loader', ...cssRules]
},
{
test: /\.css$/i,
issuer: [{
test: /\.html$/i
}],
// CSS required in templates cannot be extracted safely
// because Aurelia would try to require it again in runtime
use: cssRules
},
{
test: /\.html$/i,
loader: 'html-loader'
},
{
test: /\.js$/i,
loader: 'babel-loader',
exclude: nodeModulesDir,
options: coverage ? {
sourceMap: 'inline',
plugins: ['istanbul']
} : {}
},
{
test: /\.json$/i,
loader: 'json-loader'
},
// use Bluebird as the global Promise implementation:
{
test: /[\/\]node_modules[\/\]bluebird[\/\].+\.js$/,
loader: 'expose-loader?Promise'
},
// embed small images and fonts as Data Urls and larger ones as files:
{
test: /\.(png|gif|jpg|cur)$/i,
loader: 'url-loader',
options: {
limit: 8192
}
},
{
test: /\.woff2(\?v=[0-9]\.[0-9]\.[0-9])?$/i,
loader: 'url-loader',
options: {
limit: 10000,
mimetype: 'application/font-woff2'
}
},
{
test: /\.woff(\?v=[0-9]\.[0-9]\.[0-9])?$/i,
loader: 'url-loader',
options: {
limit: 10000,
mimetype: 'application/font-woff'
}
},
// load these fonts normally, as files:
{
test: /\.(ttf|eot|svg|otf)(\?v=[0-9]\.[0-9]\.[0-9])?$/i,
loader: 'file-loader'
}
]
},
plugins: [
new AureliaPlugin(),
new ProvidePlugin({
'Promise': 'bluebird'
}),
new ModuleDependenciesPlugin({
'aurelia-testing': ['./compile-spy', './view-spy'],
'aurelia-i18n': [{
name: 'locales/en/translation.json',
chunk: 'lang-en'
}, {
name: 'locales/pt/translation.json',
chunk: 'lang-pt'
}]
}),
new HtmlWebpackPlugin({
template: 'index.ejs',
minify: production ? {
removeComments: true,
collapseWhitespace: true
} : undefined,
metadata: {
// available in index.ejs //
title,
server,
baseUrl
}
}),
...when(extractCss, new ExtractTextPlugin({
filename: production ? '[contenthash].css' : '[id].css',
allChunks: true
})),
...when(production, new CopyWebpackPlugin([{
from: 'static/favicon.ico',
to: 'favicon.ico'
}])),
...when(analyze, new BundleAnalyzerPlugin())
]
});
The issue in the above code happens at
上面代码中的问题发生在
{
test: /\.json$/i,
loader: 'json-loader'
},
Which if you comment, lets the app compile without issues, I've searched but event though I've found similar problems to this one, I haven't found a working solution, if anyone has any suggestion in how I can solve this problem I would appreciate it.
如果你发表评论，让应用程序编译没有问题，我已经搜索过，但事件虽然我发现了与此类似的问题，但我还没有找到可行的解决方案，如果有人对我如何解决这个问题有任何建议我会很感激。
Thanks in advance.
提前致谢。
回答by Fred Kleuver
The reason it says unexpected token mis because the json-loader transforms your json into a javascript file which starts with module.exports = ...
它说的原因unexpected token m是因为 json-loader 将您的 json 转换为以 .js 开头的 javascript 文件module.exports = ..。
Of course that is not valid json (json must always start with opening brace {), hence it nags about the "m" of "module".
当然，这不是有效的 json（json 必须始终以大括号开头{），因此它会唠叨“模块”的“m”。
In other words, this error is indicative of webpack trying to apply json-loader twice in a row. Changing json-loaderto raw-loadershould get rid of webpack's wrapper javascript and pass the json as-is to whatever other plugin might be trying to load it as raw json.
换句话说，这个错误表明 webpack 尝试连续两次应用 json-loader。更改json-loader为raw-loader应该摆脱 webpack 的包装器 javascript 并将 json 原样传递给任何其他插件可能试图将其加载为原始 json 的任何其他插件。
Here's a related issue that might help you get this cleared up:
这是一个相关的问题，可以帮助您解决这个问题：
