Unexpected token m in JSON at position 0 error
On compiling an app and trying to implement the i18n library with webpack, I face this error:
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.
Here's the webconfig.js file:
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
{
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.
Thanks in advance.
Answer
The reason it says unexpected token m is because the json-loader transforms your json into a javascript file which starts with module.exports = ...
Of course that is not valid json (json must always start with opening brace {), hence it nags about the "m" of "module".
In other words, this error is indicative of webpack trying to apply json-loader twice in a row. Changing json-loader to raw-loader should 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.
Here's a related issue that might help you get this cleared up: