resolve(specifier, context, nextResolve)

加载程序 API 正在重新设计。这个钩子可能会消失或者它的签名可能会改变。不要依赖下面描述的 API。

¥The loaders API is being redesigned. This hook may disappear or its signature may change. Do not rely on the API described below.

• specifier <string>

• context <Object>

  • conditions <string[]> 相关 package.json 的导出条件

    ¥conditions <string[]> Export conditions of the relevant package.json

  • importAssertions <Object>

  • parentURL <string> | <undefined> 导入此模块的模块，如果这是 Node.js 入口点，则为未定义

    ¥parentURL <string> | <undefined> The module importing this one, or undefined if this is the Node.js entry point

• nextResolve <Function> 链中后续的 resolve 钩子，或者用户提供的最后一个 resolve 钩子之后的 Node.js 默认 resolve 钩子

  ¥nextResolve <Function> The subsequent resolve hook in the chain, or the Node.js default resolve hook after the last user-supplied resolve hook

  • specifier <string>

  • context <Object>

• 返回：<Object>

  ¥Returns: <Object>

  • format <string> | <null> | <undefined> 加载钩子的提示（可能会被忽略）'builtin' | 'commonjs' | 'json' | 'module' | 'wasm'

    ¥format <string> | <null> | <undefined> A hint to the load hook (it might be ignored) 'builtin' | 'commonjs' | 'json' | 'module' | 'wasm'

  • shortCircuit <undefined> | <boolean> 此钩子打算终止 resolve 钩子链的信号。默认值：false

    ¥shortCircuit <undefined> | <boolean> A signal that this hook intends to terminate the chain of resolve hooks. Default: false

  • url <string> 此输入解析到的绝对 URL

    ¥url <string> The absolute URL to which this input resolves

resolve 钩子链负责解析给定模块说明符和父 URL 的文件 URL，以及可选的格式（例如 'module'）作为 load 钩子的提示。如果指定了格式，load 钩子最终负责提供最终的 format 值（并且可以随意忽略 resolve 提供的提示）；如果 resolve 提供 format，则需要自定义 load 钩子，即使只是将值传递给 Node.js 默认的 load 钩子。

¥The resolve hook chain is responsible for resolving file URL for a given module specifier and parent URL, and optionally its format (such as 'module') as a hint to the load hook. If a format is specified, the load hook is ultimately responsible for providing the final format value (and it is free to ignore the hint provided by resolve); if resolve provides a format, a custom load hook is required even if only to pass the value to the Node.js default load hook.

模块说明符是 import 语句或 import() 表达式中的字符串。

¥The module specifier is the string in an import statement or import() expression.

父 URL 是导入此模块的 URL，如果这是应用的主要入口点，则为 undefined。

¥The parent URL is the URL of the module that imported this one, or undefined if this is the main entry point for the application.

context 中的 conditions 属性是适用于此解析请求的 包导出条件 的条件数组。它们可用于在别处查找条件映射或在调用默认解析逻辑时修改列表。

¥The conditions property in context is an array of conditions for package exports conditions that apply to this resolution request. They can be used for looking up conditional mappings elsewhere or to modify the list when calling the default resolution logic.

当前的 包导出条件 总是在传入钩子的 context.conditions 数组中。为了保证在调用 defaultResolve 时默认的 Node.js 模块说明符解析行为，传递给它的 context.conditions 数组必须包括最初传递到 resolve 钩子的 context.conditions 数组的所有元素。

¥The current package exports conditions are always in the context.conditions array passed into the hook. To guarantee default Node.js module specifier resolution behavior when calling defaultResolve, the context.conditions array passed to it must include all elements of the context.conditions array originally passed into the resolve hook.

export async function resolve(specifier, context, nextResolve) {
  const { parentURL = null } = context;

  if (Math.random() > 0.5) { // Some condition.
    // For some or all specifiers, do some custom logic for resolving.
    // Always return an object of the form {url: <string>}.
    return {
      shortCircuit: true,
      url: parentURL ?
        new URL(specifier, parentURL).href :
        new URL(specifier).href,
    };
  }

  if (Math.random() < 0.5) { // Another condition.
    // When calling `defaultResolve`, the arguments can be modified. In this
    // case it's adding another value for matching conditional exports.
    return nextResolve(specifier, {
      ...context,
      conditions: [...context.conditions, 'another-condition'],
    });
  }

  // Defer to the next hook in the chain, which would be the
  // Node.js default resolve if this is the last user-specified loader.
  return nextResolve(specifier);
} 拷贝