官网地址：https://docs.npmjs.com/cli/install
npm install的行为：
This command installs a package, and any packages that it depends on. If the package has a package-lock or shrinkwrap file, the installation of dependencies will be driven by that, with an npm-shrinkwrap.json taking precedence if both files exist. See package-lock.json and npm-shrinkwrap.
一个被安装包如果有依赖，其依赖也会自动被安装。
包的含义：
A package is:
a) a folder containing a program described by a package.json file
b) a gzipped tarball containing (a)
c) a url that resolves to (b)
d) a @ that is published on the registry (see npm-registry) with ©
e) a @ (see npm-dist-tag) that points to (d)
f) a that has a “latest” tag satisfying (e)
g) a that resolves to (a)
npm install执行的逻辑：
a. load the existing node_modules tree from disk
b. clone the tree
c. fetch the package.json and assorted metadata and add it to the clone
d. walk the clone and add any missing dependencies
dependencies will be added as close to the top as is possible without breaking any other modules
e. compare the original tree with the cloned tree and make a list of
f. actions to take to convert one to the other
g. execute all of the actions, deepest first
kinds of actions are install, update, remove and move
一个 SAP Spartacus 项目的package.json 例子：
{
"name": "e2",
"version": "0.0.0",
"scripts": {
"ng": "ng",
"start": "ng serve",
"build": "node --max_old_space_size=8192 ./node_modules/@angular/cli/bin/ng build",
"test": "ng test",
"lint": "ng lint",
"e2e": "ng e2e",
"prettier": "prettier --config ./.prettierrc --list-different \"projects/**/*{.ts,.scss,.html}\"",
"build:wtcmy:ssr": "ng build wtcmy --prod && ng run wtcmy:server:production",
"build:wtcph:ssr": "ng build wtcph --prod && ng run wtcph:server:production",
"build:wtcth:ssr": "ng build wtcth --prod && ng run wtcth:server:production",
"build:wtcid:ssr": "ng build wtcid --prod && ng run wtcid:server:production",
"build:wtcmy:ssr:production": "ng build wtcmy --prod && ng run wtcmy:server:production && mkdir -p ./projects/wtc/wtcmy/dist && mv ./projects/wtc/dist/wtcmy/server/main.js ./projects/wtc/wtcmy/dist/server.js && mv ./projects/wtc/dist/wtcmy ./projects/wtc/wtcmy/dist/wtcmy",
"build:wtcph:ssr:production": "ng build wtcph --prod && ng run wtcph:server:production && mkdir -p ./projects/wtc/wtcph/dist && mv ./projects/wtc/dist/wtcph/server/main.js ./projects/wtc/wtcph/dist/server.js && mv ./projects/wtc/dist/wtcph ./projects/wtc/wtcph/dist/wtcph",
"build:wtcth:ssr:production": "ng build wtcth --prod && ng run wtcth:server:production && mkdir -p ./projects/wtc/wtcth/dist && mv ./projects/wtc/dist/wtcth/server/main.js ./projects/wtc/wtcth/dist/server.js && mv ./projects/wtc/dist/wtcth ./projects/wtc/wtcth/dist/wtcth",
"build:wtcid:ssr:production": "ng build wtcid --prod && ng run wtcid:server:production && mkdir -p ./projects/wtc/wtcid/dist && mv ./projects/wtc/dist/wtcid/server/main.js ./projects/wtc/wtcid/dist/server.js && mv ./projects/wtc/dist/wtcid ./projects/wtc/wtcid/dist/wtcid",
"build:ssr": "ng build e2-lib --prod && yarn build:wtcmy:ssr:production && yarn build:wtcph:ssr:production && yarn build:wtcth:ssr:production && yarn build:wtcid:ssr:production",
"serve:wtcmy:ssr": "node projects/wtc/dist/wtcmy/server/main.js",
"serve:wtcph:ssr": "node projects/wtc/dist/wtcph/server/main.js",
"serve:wtcth:ssr": "node projects/wtc/dist/wtcth/server/main.js",
"serve:wtcid:ssr": "node projects/wtc/dist/wtcid/server/main.js",
"build:client-and-server-bundles": "ng build wtcmy --prod && ng run wtcmy:server",
"webpack:server": "webpack --config projects/wtc/webpack.server.config.js --progress --colors"
},
"schematics": "./projects/e2-spartacus-schematics/src/collection.json",
"private": true,
"dependencies": {
"@angular-slider/ngx-slider": "^2.0.3",
"@angular/animations": "9.1.9",
"@angular/common": "9.1.9",
"@angular/compiler": "9.1.9",
"@angular/core": "9.1.9",
"@angular/forms": "9.1.9",
"@angular/localize": "9.1.9",
"@angular/platform-browser": "9.1.9",
"@angular/platform-browser-dynamic": "9.1.9",
"@angular/platform-server": "9.1.9",
"@angular/router": "9.1.9",
"@angular/service-worker": "9.1.9",
"@ng-bootstrap/ng-bootstrap": "^6.1.0",
"@ng-select/ng-select": "^4.0.0",
"@ngrx/effects": "~9.1.0",
"@ngrx/router-store": "~9.1.0",
"@ngrx/store": "^9.1.0",
"@ngrx/store-devtools": "^9.1.0",
"@nguniversal/express-engine": "^9.1.0",
"@nguniversal/module-map-ngfactory-loader": "^8.1.1",
"@spartacus/core": "https://cdn.jxasp.com:9143/image/2.0.0",
"@spartacus/storefront": "https://cdn.jxasp.com:9143/image/2.0.0",
"@types/googlemaps": "^3.39.3",
"@types/swiper": "^5.2.0",
"bootstrap": "^4.4.1",
"cheerio": "^1.0.0-rc.6",
"core-js": "^2.5.4",
"deepmerge": "^4.2.2",
"express": "^4.15.2",
"helmet": "^4.2.0",
"i18next": "^19.4.5",
"i18next-xhr-backend": "^2.0.1",
"js-sha256": "^0.9.0",
"moment": "https://cdn.jxasp.com:9143/image/2.27.0",
"ng2-ion-range-slider": "^2.0.0",
"ngx-cookie-service": "10.1.1",
"ngx-infinite-scroll": "^8.0.1",
"ngx-moment": "^3.5.0",
"ngx-red-zoom": "^0.2.1",
"ngx-script-loader": "^1.3.0",
"rxjs": "^6.4.0",
"swiper": "^5.3.1",
"ts-md5": "^1.2.7",
"tslib": "^1.10.0",
"zone.js": "~0.10.2"
},
"devDependencies": {
"@angular-devkit/build-angular": "~0.901.4",
"@angular-devkit/build-ng-packagr": "~0.901.4",
"@angular/cli": "^9.1.4",
"@angular/compiler-cli": "9.1.4",
"@angular/language-service": "~9.1.0",
"@ngrx/schematics": "^8.1.0",
"@types/express": "^4.17.7",
"@types/jasmine": "~2.8.8",
"@types/jasminewd2": "~2.0.3",
"@types/node": "^12.11.1",
"codelyzer": "^5.1.2",
"jasmine-core": "^3.5.0",
"jasmine-spec-reporter": "~4.2.1",
"karma": "^4.4.1",
"karma-chrome-launcher": "~2.2.0",
"karma-coverage-istanbul-reporter": "~2.0.1",
"karma-jasmine": "^3.1.1",
"karma-jasmine-html-reporter": "^1.5.2",
"ng-packagr": "^9.0.0",
"prettier": "^1.18.2",
"protractor": "~5.4.0",
"ts-loader": "^5.3.2",
"ts-node": "~7.0.0",
"tslint": "~5.11.0",
"typescript": "3.8.3",
"webpack-cli": "^3.3.2"
}
}
