如何使用 package.json 中的“main"参数? [英] How to use the 'main' parameter in package.json?

问题描述

我已经做了很多搜索.但是，还是对Node项目的package.json中的'main'参数有疑问.

I have done quite some search already. However, still having doubts about the 'main' parameter in the package.json of a Node project.

1. 填写此字段有何帮助?换一种方式问，如果出现这个字段，我可以以不同的风格启动模块吗?
2. 我可以在主参数中填充多个脚本吗?如果是，它们会作为两个线程启动吗?如果不是，我如何在一个模块中启动两个脚本并让它们并行运行?

我知道第二个问题很奇怪.这是因为我在 OpenShift 上托管了一个 Node.js 应用程序，但该应用程序由两个主要组件组成.一个是 REST API，一个是通知传送服务.

I know that the second question is quite weird. It is because I have hosted a Node.js application on OpenShift but the application consists of two main components. One being a REST API and one being a notification delivering service.

如果将它们实现为单个线程，我担心通知传递过程会阻塞 REST API.但是，它们必须连接到同一个 MongoDB 盒式磁带.此外，如果可能的话，如果两个组件可以在同一档位中使用，我想节省一个档位.

I am afraid that the notification delivering process would block the REST API if they were implemented as a single thread. However, they have to connect to the same MongoDB cartridge. Moreover, I would like to save one gear if both the components could be serving in the same gear if possible.

欢迎提出任何建议.

推荐答案

来自 npm 文档:

主要字段是一个模块 ID，它是您的主要入口点程序.也就是说，如果您的包名为 foo，并且用户安装了它，然后确实需要(foo")，然后是您的主模块的导出对象将被返回.

The main field is a module ID that is the primary entry point to your program. That is, if your package is named foo, and a user installs it, and then does require("foo"), then your main module's exports object will be returned.

这应该是相对于包根目录的模块 ID文件夹.

This should be a module ID relative to the root of your package folder.

对于大多数模块来说，拥有一个主脚本和通常不会有太多其他事情.

For most modules, it makes the most sense to have a main script and often not much else.

简而言之:

1. 如果包的入口点与其根目录中的 index.js 不同，则 package.json 中只需要一个 main 参数文件夹.例如，人们经常把入口点放在lib/index.js 或lib/.js，在这种情况下，对应的脚本必须描述为<package.json 中的 code>main.
2. 不能有两个脚本作为 main，因为入口点 require('yourpackagename') 必须明确定义.

1. You only need a main parameter in your package.json if the entry point to your package differs from index.js in its root folder. For example, people often put the entry point to lib/index.js or lib/<packagename>.js, in this case the corresponding script must be described as main in package.json.
2. You can't have two scripts as main, simply because the entry point require('yourpackagename') must be defined unambiguously.

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