Webpack file-loader outputs [object Module]

I am using webpack with HtmlWebpackPlugin, html-loader and file-loader. I have a simple project structure in which I use no frameworks, but only typescript. Thus, I write my HTML code directly to index.html. I also use this HTML file as my template in HtmlWebpackPlugin.

As all websites do I need to put an image which refers to a PNG in my assets folder. file-loader should load the file correctly put the new filename inside the src tag but that is not what is happening. Instead, as the value of src tag, I have [object Module]. I assume the file-loader emits some object and it is represented like this when its .toString() method is run. However, I can see that file-loader has processed the file successfully and emitted with new name to the output path. I get no errors. Here is my webpack configuration and index.html.

const projectRoot = path.resolve(__dirname, '..');

{
  entry: path.resolve(projectRoot, 'src', 'app.ts'),
  mode: 'production',
  output: {
    path: path.resolve(projectRoot, 'dist'),
    filename: 'app.bundle.js'
  },
  resolve: {
    extensions: ['.ts', '.js']
  },
  module: {
    rules: [
      {
        test: /.html$/i,
        use: 'html-loader'
      },
      {
        test: /.(eot|ttf|woff|woff2|svg|png)$/i,
        use: 'file-loader'
      },
      {
        test: /.scss$/i,
        use: [
          {
            loader: MiniCssExtractPlugin.loader,
            options: {
              hmr: false
            }
          },
          {
            loader: 'css-loader',
            options: {
              sourceMap: false
            }
          },
          {
            loader: 'sass-loader',
            options: {
              sourceMap: false
            }
          }
        ]
      },
      {
        exclude: /node_modules/,
        test: /.ts$/,
        use: 'ts-loader'
      }
    ]
  },
  plugins: [
    new CleanWebpackPlugin(),
    new HtmlWebpackPlugin({
      template: path.resolve(projectRoot, 'src', 'index.html')
    }),
    new MiniCssExtractPlugin({
      filename: '[name].[hash].css',
      chunkFilename: '[id].[hash].css',
      ignoreOrder: false
    })
  ]
};

index.html:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title></title>
  </head>
  <body class="dark">
    <header>
      <nav class="navigation">
        <div class="left">
          <img src="assets/logo.png" class="logo"> <!-- This logo is output as [object Module] -->
        </div>
        <div class="right">

        </div>
      </nav>
    </header>
  </body>
</html>

Project structure:

config/
    webpack.config.js
dist/
src/
    styles/
    assets/
        logo.png
    index.html
    app.ts

Edit My package.json dependencies:

"clean-webpack-plugin": "^3.0.0",
"css-loader": "^3.2.0",
"file-loader": "^5.0.2",
"html-webpack-plugin": "^3.2.0",
"mini-css-extract-plugin": "^0.8.0",
"node-sass": "^4.13.0",
"sass-loader": "^8.0.0",
"style-loader": "^1.0.0",
"ts-loader": "^6.2.1",
"typescript": "^3.7.2",
"webpack": "^4.41.2",
"webpack-cli": "^3.3.10",
"webpack-dev-server": "^3.9.0"

Answer

Per the file-loader docs:

By default, file-loader generates JS modules that use the ES modules syntax. There are some cases in which using ES modules is beneficial, like in the case of module concatenation and tree shaking.

It seems that webpack resolves ES module require() calls to an object that looks like this: {default: module}, instead of to the flattened module itself. This behavior is somewhat controversial and is discussed in this issue.

Therefore, to get your src attribute to resolve correctly, you need to be able to access the default property of the exported module. If you’re using a framework, you should be able to do something like this:

<img src="require('assets/logo.png').default"/>

Alternatively, you can enable file-loader’s CommonJS module syntax, which webpack will resolve directly to the module itself. Set esModule:false in your webpack config.

webpack.config.js:

 {
        test: /.(png|jpe?g|gif)$/i,
        use: [
          {
            loader: 'file-loader',
            options: {
              esModule: false,
            },
          },
        ],
      },

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