npm - 需要一个对等点，但没有安装

Question

我的 package.json看起来像这样

{
  "name": "hello-world",
  "version": "1.0.0",
  "description": "The Hello World",
  "author": "",
  "license": "MIT",
  "scripts": {
    "start": "tsc && concurrently \"npm run tsc:w\" \"npm run lite\" ",
    "lite": "lite-server",
    "postinstall": "typings install",
    "tsc": "tsc",
    "tsc:w": "tsc -w",
    "typings": "typings"
  },
  "dependencies": {
    "@angular/common": "~2.0.1",
    "@angular/compiler": "~2.0.1",
    "@angular/core": "~2.0.1",
    "@angular/http": "~2.0.1",
    "@angular/platform-browser": "~2.0.1",
    "@angular/platform-browser-dynamic": "~2.0.1",
    "@angular/router": "~3.0.1",
    "@angular/upgrade": "~2.0.1",

    "systemjs": "0.19.39",
    "core-js": "^2.4.1",
    "reflect-metadata": "^0.1.8",
    "rxjs": "5.0.0-beta.12",
    "zone.js": "^0.6.25",

    "angular-in-memory-web-api": "~0.1.1",
    "bootstrap": "4.0.0-alpha.4"
  },
  "devDependencies": {
    "concurrently": "^3.0.0",
    "lite-server": "^2.2.2",
    "typescript": "^2.0.3",
    "typings": "^1.4.0"
  }
}

当我跑 npm i它运行成功，但我收到了一些警告。

npm WARN angular-in-memory-web-api@0.1.17 requires a peer of rxjs@5.0.0-rc.4 but none was installed.
npm WARN angular-in-memory-web-api@0.1.17 requires a peer of zone.js@^0.7.2 but none was installed.

我将这些行添加到 package.json

"peerDependencies": {
    "rxjs": "5.0.0-rc.4",
    "zone.js": "^0.7.2"
}

但是当我运行 npm i再次我仍然收到此警告

npm WARN hello-world@1.0.0 requires a peer of rxjs@5.0.0-rc.4 but none was installed.
npm WARN hello-world@1.0.0 requires a peer of zone.js@^0.7.2 but none was installed.
npm WARN angular-in-memory-web-api@0.1.17 requires a peer of rxjs@5.0.0-rc.4 but none was installed.
npm WARN angular-in-memory-web-api@0.1.17 requires a peer of zone.js@^0.7.2 but none was installed.

主应用程序的附加警告。
为什么会这样以及如何摆脱这个警告？

Answer 1

TL; 博士

对等依赖 是一种特殊的依赖项 - 它们由不直接调用它们的包使用，赋予用户(您)控制权。因此，您必须手动安装这些软件包。

您不需要添加 peerDependencies给您的 package.json .

您看到这些错误的原因是，您的某些依赖项声明 rxjs@5.0.0-rc.4和 zone.js@^0.7.2在他们的 package.json如 peerDependencies .这就是为什么当您添加 peerDependencies 时在您的 package.json ，您会收到两次这些警告。

了解更多 对等依赖 我建议阅读这些:

Peer Dependencies

What are those PeerDependencies in a NodeJS project?

此 great answer