import PropertyType from '../../../components/PropertyType.tsx'; import WebpackLicense from '@components/WebpackLicense';

Stats

Generate packaging information that can be used to analyze module dependencies and optimize compilation speed.

:::info Output JSON file of stats

Using @rspack/cli, rspack build --json stats.json.
Using Rspack's JavaScript API, stats.toJson(options), stats.toString(options).

:::

Type:

type StatsPresets =
  | 'normal'
  | 'none'
  | 'verbose'
  | 'errors-only'
  | 'errors-warnings'
  | 'minimal'
  | 'detailed'
  | 'summary';

type Stats = boolean | StatsOptions | StatsPresets;

Default: { "preset":"errors-warnings", "timings":true }

Stats presets

Preset	Description
`'normal'` (`true`)	Output by default value of stats options
`'none'` (`false`)	Output nothing
`'verbose'`	Output everything
`'errors-only'`	Output only error-related information
`'errors-warnings'`	Output only error and warning related information
`'minimal'`	Output only when errors or new compilation happen
`'detailed'`	Output everything except `chunkModules` and `chunkRootModules`
`'summary'`	Output only the summary information

You can specify exactly which packing information to output, all the following fields are optional.

Preset options

stats.all

A fallback value for stats options when an option is not defined. It has precedence over local Rspack defaults.

:::warning Enabling stats.all will lead to a large amount of data transmission between Rust and JavaScript, which will significantly increase the time consumption for stats generation. Please use it with caution. :::

stats.preset

Sets the preset for the type of information that gets displayed. It is useful for extending stats behaviours.

Asset options

stats.assets

Whether to display the asset information. See Asset Object for more details.

stats.assetsSort

Sort the assets by a given field. All of the sorting fields are allowed to be used. Use ! prefix in the value to reverse the sort order by a given field.

stats.assetsSpace

How many items of assets should be displayed (groups will be collapsed to fit this space).

stats.relatedAssets

Whether to display information about assets that are related to other assets (like SourceMaps for assets).

stats.excludeAssets

<PropertyType type="boolean | string | RegExp | ((name: string, asset: any) => boolean) | Array<string | RegExp | ((name: string, asset: any) => boolean)>" defaultValueList={[{ defaultValue: 'false' }]} />

Exclude the matching assets information. This can be done with a string, a RegExp, or a function that receives the asset name and asset object and returns a boolean. stats.excludeAssets can be an array of any of the above.

stats.cachedAssets

Whether to display information about the cached assets. Setting stats.cachedAssets to false will tell stats to only show the emitted files (not the ones that were built).

Asset grouping options

stats.groupAssetsByChunk

Whether to group assets by how their are related to chunks.

stats.groupAssetsByEmitStatus

Whether to group assets by their status (emitted, compared for emit or cached).

stats.groupAssetsByExtension

Whether to group assets by their extension.

stats.groupAssetsByInfo

Whether to group assets by their asset info (immutable, development, hotModuleReplacement, etc).

stats.groupAssetsByPath

Whether to group assets by their asset path.

Chunk options

stats.chunks

Whether to display information about the chunk, see chunk object for more details.

stats.chunkModules

Whether to display information about the built modules to information about the chunk.

stats.chunkModulesSpace

How many items of chunk modules should be displayed (groups will be collapsed to fit this space).

stats.dependentModules

Whether to display chunk modules that are dependencies of other modules of the chunk.

stats.chunkOrigins

Whether to display information about the origins of chunks and chunk merging.

stats.chunkRelations

Whether to display chunk parents, children and siblings.

stats.chunksSort

Sort the chunks by a given field. All of the sorting fields are allowed to be used. Use ! prefix in the value to reverse the sort order by a given field.

stats.ids

Whether to display IDs of modules and chunks.

ChunkGroup options

stats.chunkGroups

Whether to display information about the namedChunkGroups, see chunk group object for more details.

stats.chunkGroupAuxiliary

Whether to display auxiliary assets in chunk groups.

stats.chunkGroupChildren

Whether to display children of the chunk groups (e.g. prefetched, preloaded chunks and assets).

stats.chunkGroupMaxAssets

How many assets should be displayed in chunk groups.

stats.entrypoints

Whether to display the entry points with the corresponding bundles, , see entrypoint object for more details.

When stats.entrypoints is set to 'auto', Rspack will decide automatically whether to display the entry points in the stats output.

Module options

stats.modules

Whether to display information about the built modules, see module object for more details.

stats.moduleTrace

Whether to display dependencies and the origin of warnings/errors.

stats.moduleAssets

Whether to add information about assets inside modules.

stats.modulesSpace

How many items of modules should be displayed (groups will be collapsed to fit this space).

stats.modulesSort

Sort the modules by a given field. All of the sorting fields are allowed to be used. Use ! prefix in the value to reverse the sort order by a given field.

stats.reasons

Whether to display information about the reasons of why modules are included.

stats.reasonsSpace

How many characters should the reasons be displayed (groups will be collapsed to fit this space).

stats.source

Whether to display the source code of modules.

stats.depth

Whether to display the distance from the entry point for each module.

stats.orphanModules

Whether to display the orphan modules.

A module is an orphan if it is not included in any chunk.

stats.runtimeModules

Whether to display information about runtime modules.

The runtime modules are built-in modules of Rspack, used to provide various runtime capabilities.

stats.cachedModules

Whether to display information about cached (not built) modules.

stats.excludeModules

<PropertyType type="boolean | string | RegExp | ((name: string, module: any, type: any) => boolean) | Array<string | RegExp | ((name: string, module: any, type: any) => boolean)>" defaultValueList={[{ defaultValue: 'false' }]} />

Exclude the matching modules information. This can be done with a string, a RegExp, or a function that receives the module name, module object, and module type and returns a boolean. stats.excludeModules can be an array of any of the above.

stats.nestedModules

Whether to display information about modules nested in other modules (like with module concatenation).

stats.nestedModulesSpace

How many items of nested modules should be displayed (groups will be collapsed to fit this space).

Module grouping options

stats.groupModulesByAttributes

Whether to group modules by their attributes (errors, warnings, assets, optional, orphan, or dependent).

stats.groupModulesByCacheStatus

Whether to group modules by their cache status (cached or built and cacheable).

stats.groupModulesByExtension

Whether to group modules by their extension.

stats.groupModulesByPath

Whether to group modules by their path.

stats.groupModulesByType

Whether to group modules by their type.

stats.groupModulesByLayer

Whether to group modules by their layer.

stats.groupReasonsByOrigin

Group reasons by their origin module to avoid large set of reasons.

Optimization options

stats.providedExports

Whether to display the exports of the modules.

stats.usedExports

Whether to display which exports of a module are used.

stats.optimizationBailout

Whether to display the reasons why optimization bailed out for modules.

Error/Warning options

stats.errors

Whether to display the errors.

stats.errorsCount

Whether to display the errors count.

stats.errorDetails

Whether to display the details to the errors. It defaults to 'auto' which will show error details when there're only 2 or less errors.

stats.errorsSpace

How many lines should an error be displayed.

stats.errorStack

Whether to display stack trace of errors.

stats.warnings

Whether to display the warnings.

stats.warningsCount

Whether to display the warnings count.

stats.warningsSpace

How many lines should a warning be displayed.

Logging options

stats.logging

Whether to add logging output:

'none', false: disable logging
'error': errors only
'warn': errors and warnings only
'info': errors, warnings, and info messages
'log', true: errors, warnings, info messages, log messages, groups, clears. Collapsed groups are displayed in a collapsed state.
'verbose': log everything except debug and trace. Collapsed groups are displayed in expanded state.

stats.loggingDebug

Type:

type FilterItemTypes = RegExp | string | ((value: string) => boolean);
type StatsLoggingDebug = boolean | FilterItemTypes | FilterItemTypes[];

Whether to display the debug information of the specified loggers such as Plugins or Loaders. When stats.logging is set to false, stats.loggingDebug option is ignored.

export default {
  stats: {
    loggingDebug: [
      'MyPlugin',
      /rspack/, // To get core logging
    ],
  },
};

stats.loggingTrace

Whether to display stack traces in the logging output for errors, warnings and traces.

stats.colors

Whether to output in the different colors.

Defaults to true when executing rspack build in an environment that supports color output.

Compilation options

stats.hash

Whether to display information about the hash of the compilation.

stats.env

Whether to display the --env information.

stats.builtAt

Whether to display the build date and the build time information.

stats.version

Whether to add information about the Rspack version used.

stats.context

Whether to display the base directory as an absolute path for shortening the module specifier.

stats.publicPath

Whether to display the publicPath.

stats.outputPath

Whether to display the output.path.

stats.children

Whether to display the output.path.

stats.performance

Whether to display performance hint when the file size exceeds performance.maxAssetSize.

stats.timings

Whether to display the timing information.

Sorting fields

For assetsSort, chunksSort and modulesSort there are several possible fields that you can sort items by:

'id': the item's id, an item is an asset, a module or a chunk.
'name': the item's name that was assigned to it upon importing.
'size': the size of item in bytes.
'chunks': what chunks the item originates from (for example, if there are multiple subchunks for one chunk: the subchunks will be grouped according to their main chunk).
'errors': number of errors in items.
'warnings': number of warnings in items.
'failed': whether the item has failed compilation.
'cacheable': whether the item is cacheable.
'built': whether the item has been built.
'prefetched': whether the item will be prefetched.
'optional': whether the item is optional.
'identifier': identifier of the item.
'index': item's processing index.
'issuer': the identifier of the issuer.
'issuerId': the id of the issuer.
'issuerName': the name of the issuer.
'issuerPath': the full issuer path.

Extending stats behaviours

If you want to use the preset output behavior but want to output more or less of individual fields, you can customize the output behavior of the fields after specifying preset or all.

For example, only the error and the reason why the module was introduced are output.

export default {
  stats: {
    preset: 'errors-only',
    reasons: true,
  },
};