[Bug]: wrong url path when using `generator.publicPath` and asset module

[SoonIter]

Bug report

configure webpack with generator.asset.publicPath = '' and assetModule as below

module.exports = {
  module: {
    generator: {
      asset: {
        publicPath: '',
      },
    },
    rules: [
      {
        test: /\.svg$/i,
        oneOf: [
          /* config.module.rule('svg').oneOf('svg-asset') */
          {
            type: 'asset',
            parser: {
              dataUrlCondition: {
                maxSize: 1000,
              },
            },
            generator: {
              filename: 'static/svg/[name].svg',
            },
          },
        ],
      },
}

Actual Behavior

webpack-dist/static/css/index.392c62df.css

.a {
  background: url(../..//static/svg/react.svg);
}

Expected Behavior

.a {
  background: url(../../static/svg/react.svg);
}

How Do We Reproduce?

https://github.com/SoonIter/rspack-css-extract-wrong-path

pnpm i
npm run build # both rspack and webpack
# or npm run build:webpack

Please paste the results of npx webpack-cli info here, and mention other relevant information

[SoonIter]

It didn't appear in experiments.css in
webpack/webpack#17170

it may related to base_uri replacement logic and importModule result
#915

[SoonIter]

@alexander-akait @vankop
Would you mind checking this, please? :)

[alexander-akait]

@SoonIter Sorry for delay, why you need publicPath: ''? I strongly recommend avoid it and use auto by default

[SoonIter]

@SoonIter Sorry for delay, why you need publicPath: ''? I strongly recommend avoid it and use auto by default

“auto" is not implemented, any value of generator.publicPath would cause this bug

[SoonIter]

after set

module: {
    generator: {
      asset: {
        publicPath: 'auto',
      },
    },
}

webpack-dist/static/css/index.392c62df.css

.a {
  background: url(../..//autostatic/svg/react.svg);
}

[alexander-akait]

@SoonIter Remove publicPath everywhere, here is fixed version:

const config = {
  mode: 'production',
  devtool: false,
  entry: {
    index: [join(__dirname, './src/index.mjs')],
    // 'assets/react': [join(__dirname, './src/assets/react.svg')],
  },
  plugins: [new HtmlWebpackPlugin()],
  optimization: {
    minimize: false,
  },
  output: {
    clean: true,
    path: isRunningWebpack
      ? path.resolve(__dirname, 'webpack-dist')
      : path.resolve(__dirname, 'rspack-dist'),
    filename: '[name].js',
    // publicPath: 'auto',
    // assetModuleFilename: 'static/asset/[name].[ext]',
    // module: true,
    // chunkFormat: 'module',
    // chunkLoading: 'import',
    // workerChunkLoading: 'import',
    // wasmLoading: 'fetch',
  },
  stats: {
    children: true,
  },
  module: {
    rules: [
      {
        resourceQuery: /raw/,
        type: 'asset/source',
      },
      {
        test: /\.svg$/i,
        oneOf: [
          /* config.module.rule('svg').oneOf('svg-asset-url') */
          {
            type: 'asset/resource',
            resourceQuery: /(__inline=false|url)/,
            generator: {
              filename: 'static/svg/[name].svg',
            },
          },
          /* config.module.rule('svg').oneOf('svg-asset-inline') */
          {
            type: 'asset/inline',
            resourceQuery: /inline/,
          },
          /* config.module.rule('svg').oneOf('svg-asset') */
          {
            type: 'asset',
            parser: {
              dataUrlCondition: {
                maxSize: 1000,
              },
            },
            generator: {
              filename: 'static/svg/[name].svg',
            },
          },
        ],
      },
      ...(isRunningRspack
        ? [
            {
              test: /\.css$/,
              type: 'javascript/auto',
              dependency: {
                not: 'url',
              },
              sideEffects: true,
              use: [
                {
                  loader: rspack.CssExtractRspackPlugin.loader,
                  options: {
                    // publicPath: 'auto',
                  },
                },
                {
                  loader: 'css-loader',
                  options: {
                    importLoaders: 1,
                    modules: {
                      auto: true,
                      namedExport: false,
                      exportGlobals: false,
                      exportLocalsConvention: 'camelCase',
                      localIdentName: '[local]-[hash:base64:6]',
                    },
                    sourceMap: true,
                  },
                },
              ],
            },
          ]
        : [
            {
              test: /\.css$/,
              type: 'javascript/auto',
              dependency: {
                not: 'url',
              },
              sideEffects: true,
              use: [
                {
                  loader: MiniCssExtractPlugin.loader,
                },
                {
                  loader: 'css-loader',
                  options: {
                    importLoaders: 1,
                    modules: {
                      auto: true,
                      namedExport: false,
                      exportGlobals: false,
                      exportLocalsConvention: 'camelCase',
                      localIdentName: '[local]-[hash:base64:6]',
                    },
                    sourceMap: true,
                  },
                },
              ],
            },
          ]),
    ],
  },
  experiments: {
    css: true,
    outputModule: true,
  },
  plugins: [
    isRunningRspack
      ? new rspack.CssExtractRspackPlugin({
          filename: 'static/css/[name].[contenthash:8].css',
          chunkFilename: 'static/css/async/[name].[contenthash:8].css',
          ignoreOrder: true,
        })
      : new MiniCssExtractPlugin({
          filename: 'static/css/[name].[contenthash:8].css',
          chunkFilename: 'static/css/async/[name].[contenthash:8].css',
          ignoreOrder: true,
        }),
  ],
};

Don't mix publicPath: '' and publicPath: 'auto', because it is different things and can lead to such things, when you have publicPath: '' webpack thinks you have empty public path and starts url with / (i.e. /autostatic/svg/react.svg), but when globally you have auto, so when chunk is generating it add ../../ to work from room and be relative, so you got url(../..//autostatic/svg/react.svg);

[alexander-akait]

There is the same issue - #1005

[SoonIter]

Don't mix publicPath: '' and publicPath: 'auto', because it is different things and can lead to such things, when you have publicPath: '' webpack thinks you have empty public path and starts url with / (i.e. /autostatic/svg/react.svg)

🤔 Yes, but when setting output.publicPath: '/' and generator['asset'].publicPath: '/', shouldn't they produce consistent results?

only output.publicPath: '/' ✅

yeah, this is a commonly used case

.a {
  background: url(/static/svg/react.svg);
}

output.publicPath: '/' and generator['asset'].publicPath: '/' ❌

config can be seen at https://github.com/SoonIter/rspack-css-extract-wrong-path/blob/575267927cbda52385694afd76071fb0a39d1b31/rspack.config.mjs

.a {
  background: url(../..//static/svg/react.svg);
}

according to investigation of #1005 (comment), i think it is a bug of base_uri replacement bug when using associated with asset-module

[alexander-akait]

Yes, it is a bug/limitation as was described here - #1005 (comment)

I recommend don't set multiple publicPath, because extracting and rewriting URLs can be hard in such cases, I want to close this issue, because it is a duplicate of #1005, anyway feel free to feedback there and feel free to send a PR

It is on my radar, by has low priority because in mostly cases it can be simplified and fixed by removing extra publicPath and it happens very rare

[alexander-akait]

I can continue discussion there - #1005