我需要帮助将以下代码从 webpack 3 迁移到 4。
new webpack.optimize.CommonsChunkPlugin({
minChunks: module => module.context && module.context.indexOf("node_modules") !== -1,
name: "vendor",
chunks: ["main"]
})
我有两个入口文件，并且只希望第一个的依赖项包含在供应商块中。第二个条目的依赖项都应该保留在它自己的包中。
我们已弃用并删除了 CommonsChunkPlugin，并将其替换为一组默认值和易于覆盖的 API，称为
optimization.splitChunks.
webpack.optimize.CommonsChunkPlugin has been removed,
please use config.optimization.splitChunks instead.
您不再需要使用这些插件：
NoEmitOnErrorsPlugin -> optimization.noEmitOnErrors（在生产模式下 默认开启） ModuleConcatenationPlugin -> optimization.concatenateModules（在 prod 模式下默认开启） NamedModulesPlugin -> optimization.namedModules（在开发模式下默认开启）
使用mini-css-extract-plugin而不是text-extract-plugin. 用于webpack-bundle-analyzer以图形方式分析您的捆绑输出。
入口脚本是应用程序的真正“入口脚本”，不要将供应商文件显式添加entry:到webpack.config.js. SPA 应用程序有一个入口，而像经典ASP.NET MVC应用程序这样的多页应用程序有多个入口点。Webpack 将从你的入口脚本构建一个依赖图，并为你的应用程序生成优化的包。
如果你想从旧的 webpack 版本迁移，最好查看迁移指南
Tree Shaking（死代码消除）仅在生产模式下启用。
Webpack 4，捆绑资产的新方式
（你必须从你的脑海中移除你的 CommonsChunkPlugin-thinking）
！！！同时更新了 webpack 文档，SplitChunks增加了一个部分！！！
Webpack 4 现在默认自动进行优化。它根据以下条件分析您的依赖关系图并创建最佳捆绑包（输出）：
- 可以共享新块或模块来自 node_modules 文件夹
- 新块将大于 30kb（在 min+gz 之前）
- 按需加载块时的最大并行请求数 <= 5
- 初始页面加载时的最大并行请求数 <= 3
所有这些都可以使用 SplitChunksPlugin 进行调整！（请参阅 SplitChunksPlugin 文档）
有关如何使用新optimization.splitChunksAPI的更详细说明。
CommonsChunkPlugin 被移除是因为它有很多问题：
SplitChunksPlugin 也有一些很棒的属性：
关于您的问题，您希望将 entry1 和 entry2 的所有部门拆分为单独的包。
optimization: {
splitChunks: {
cacheGroups: {
"entry1-bundle": {
test: /.../, // <-- use the test property to specify which deps go here
chunks: "all",
name: "entry1-bundle",
/** Ignore minimum size, minimum chunks and maximum requests and always create chunks for this cache group */
enforce: true,
priority: .. // use the priority, to tell where a shared dep should go
},
"entry2-bundle": {
test: /..../, // <-- use the test property to specify which deps go here
chunks: "all",
name: "entry2-bundle",
enforce: true,
priority: ..
}
}
}
},
如果不添加 optimization:splitChunks 条目，则默认设置如下：
splitChunks: {
chunks: 'async',
minSize: 30000,
minRemainingSize: 0,
maxSize: 0,
minChunks: 1,
maxAsyncRequests: 6,
maxInitialRequests: 4,
automaticNameDelimiter: '~',
automaticNameMaxLength: 30,
cacheGroups: {
vendors: {
test: /[\\/]node_modules[\\/]/,
priority: -10
},
default: {
minChunks: 2,
priority: -20,
reuseExistingChunk: true
}
}
}
您可以设置 optimization.splitChunks.cacheGroups。默认为 false 以禁用默认缓存组，与供应商缓存组相同！
以下是其他一些带有说明的SplitChunks 配置示例。
SplitChunksOptions，可以在此处找到。CachGroupOptionsOptimization
下面的接口定义可能不是 100% 准确，但有助于简单概述：
SplitChunksOptions界面
interface SplitChunksOptions {
/** Select chunks for determining shared modules (defaults to \"async\", \"initial\" and \"all\" requires adding these chunks to the HTML) */
chunks?: "initial" | "async" | "all" | ((chunk: compilation.Chunk) => boolean);
/** Minimal size for the created chunk */
minSize?: number;
/** Minimum number of times a module has to be duplicated until it's considered for splitting */
minChunks?: number;
/** Maximum number of requests which are accepted for on-demand loading */
maxAsyncRequests?: number;
/** Maximum number of initial chunks which are accepted for an entry point */
maxInitialRequests?: number;
/** Give chunks created a name (chunks with equal name are merged) */
name?: boolean | string | ((...args: any[]) => any);
/** Assign modules to a cache group (modules from different cache groups are tried to keep in separate chunks) */
cacheGroups?: false | string | ((...args: any[]) => any) | RegExp | { [key: string]: CacheGroupsOptions };
}
CacheGroupsOptions界面：
interface CacheGroupsOptions {
/** Assign modules to a cache group */
test?: ((...args: any[]) => boolean) | string | RegExp;
/** Select chunks for determining cache group content (defaults to \"initial\", \"initial\" and \"all\" requires adding these chunks to the HTML) */
chunks?: "initial" | "async" | "all" | ((chunk: compilation.Chunk) => boolean);
/** Ignore minimum size, minimum chunks and maximum requests and always create chunks for this cache group */
enforce?: boolean;
/** Priority of this cache group */
priority?: number;
/** Minimal size for the created chunk */
minSize?: number;
/** Minimum number of times a module has to be duplicated until it's considered for splitting */
minChunks?: number;
/** Maximum number of requests which are accepted for on-demand loading */
maxAsyncRequests?: number;
/** Maximum number of initial chunks which are accepted for an entry point */
maxInitialRequests?: number;
/** Try to reuse existing chunk (with name) when it has matching modules */
reuseExistingChunk?: boolean;
/** Give chunks created a name (chunks with equal name are merged) */
name?: boolean | string | ((...args: any[]) => any);
}
Optimization界面
interface Optimization {
/**
* Modules are removed from chunks when they are already available in all parent chunk groups.
* This reduces asset size. Smaller assets also result in faster builds since less code generation has to be performed.
*/
removeAvailableModules?: boolean;
/** Empty chunks are removed. This reduces load in filesystem and results in faster builds. */
removeEmptyChunks?: boolean;
/** Equal chunks are merged. This results in less code generation and faster builds. */
mergeDuplicateChunks?: boolean;
/** Chunks which are subsets of other chunks are determined and flagged in a way that subsets don’t have to be loaded when the bigger chunk has been loaded. */
flagIncludedChunks?: boolean;
/** Give more often used ids smaller (shorter) values. */
occurrenceOrder?: boolean;
/** Determine exports for each module when possible. This information is used by other optimizations or code generation. I. e. to generate more efficient code for export * from. */
providedExports?: boolean;
/**
* Determine used exports for each module. This depends on optimization.providedExports. This information is used by other optimizations or code generation.
* I. e. exports are not generated for unused exports, export names are mangled to single char identifiers when all usages are compatible.
* DCE in minimizers will benefit from this and can remove unused exports.
*/
usedExports?: boolean;
/**
* Recognise the sideEffects flag in package.json or rules to eliminate modules. This depends on optimization.providedExports and optimization.usedExports.
* These dependencies have a cost, but eliminating modules has positive impact on performance because of less code generation. It depends on your codebase.
* Try it for possible performance wins.
*/
sideEffects?: boolean;
/** Tries to find segments of the module graph which can be safely concatenated into a single module. Depends on optimization.providedExports and optimization.usedExports. */
concatenateModules?: boolean;
/** Finds modules which are shared between chunk and splits them into separate chunks to reduce duplication or separate vendor modules from application modules. */
splitChunks?: SplitChunksOptions | false;
/** Create a separate chunk for the webpack runtime code and chunk hash maps. This chunk should be inlined into the HTML */
runtimeChunk?: boolean | "single" | "multiple" | RuntimeChunkOptions;
/** Avoid emitting assets when errors occur. */
noEmitOnErrors?: boolean;
/** Instead of numeric ids, give modules readable names for better debugging. */
namedModules?: boolean;
/** Instead of numeric ids, give chunks readable names for better debugging. */
namedChunks?: boolean;
/** Defines the process.env.NODE_ENV constant to a compile-time-constant value. This allows to remove development only code from code. */
nodeEnv?: string | false;
/** Use the minimizer (optimization.minimizer, by default uglify-js) to minimize output assets. */
minimize?: boolean;
/** Minimizer(s) to use for minimizing the output */
minimizer?: Array<Plugin | Tapable.Plugin>;
/** Generate records with relative paths to be able to move the context folder". */
portableRecords?: boolean;
}
}
我有两个入口文件，并且只希望第一个的依赖项包含在供应商块中。第二个条目的依赖项都应该保留在它自己的包中。
假设您的入口点是mainand secondary：
entry: {
main: 'path-to/main.js',
secondary: 'path-to/secondary.js'
}
使用webpack-4您可以仅从块中提取vendors模块，但使用您要创建的函数将在该块中main引用的其他第三方模块保留在该块中。secondarytestcacheGroups
optimization: {
splitChunks: {
cacheGroups: {
vendors: {
name: 'vendors',
chunks: 'all',
reuseExistingChunk: true,
priority: 1,
enforce: true,
test(module, chunks) {
const name = module.nameForCondition && module.nameForCondition();
return chunks.some(chunk => {
return chunk.name === 'main' && /[\\/]node_modules[\\/]/.test(name);
});
}
},
secondary: {
name: 'secondary',
chunks: 'all',
priority: 2,
enforce: true,
test(module, chunks) {
return chunks.some(chunk => chunk.name === 'secondary');
}
}
}
}
}
我花了一段时间才弄明白，但对我来说关键的实现是chunkswebpack 4 中的参数现在采用了一个函数，它只允许你包含一个特定的条目。我假设这是最近的更改，因为在发布时它不在官方文档中。
splitChunks: {
cacheGroups: {
vendor: {
name: 'vendor',
chunks: chunk => chunk.name == 'main',
reuseExistingChunk: true,
priority: 1,
test: module =>
/[\\/]node_modules[\\/]/.test(module.context),
minChunks: 1,
minSize: 0,
},
},
},
请注意，我通过在我的 webpack.common.js 中更改此问题更正了该问题：
plugins: [
new webpack.optimize.CommonsChunkPlugin({
name: ['vendor']
})
]
对此：
optimization: {
runtimeChunk: "single", // enable "runtime" chunk
splitChunks: {
cacheGroups: {
vendor: {
test: /[\\/]node_modules[\\/]/,
name: "vendor",
chunks: "all"
}
}
}
},