笔记

约 3668 字大约 12 分钟

2025-11-09

请求的流转过程

[请求 Request] --> [DTO 数据传输对象] --> [Controller 控制器（Handler）] --> [Service 服务层] --> [Repository / 数据层]

在 Nest 应用中，一个典型的请求会按照如下步骤进行：

客户端发送请求 请求会被路由匹配到对应的控制器（Controller）方法。
DTO（Data Transfer Object）接收参数 控制器方法在接收参数时，会使用定义好的 DTO 类 来描述和验证请求体结构。 DTO 通常配合 class-validator 与 class-transformer 实现参数校验与类型转换。
Controller（控制器）处理请求 控制器中的每个方法称为 handler（处理器）。它负责：
- 解析请求参数（通过装饰器如 @Body(), @Param(), @Query() 等）
- 调用对应的业务逻辑（Service）
- 返回响应结果
可以理解为 Controller 是路由与业务逻辑之间的中间层。

依赖注入（IoC 容器）

Nest 采用 IoC（控制反转） 与 依赖注入（DI） 模式来管理模块和类之间的依赖关系。

框架会自动从 IoC 容器 中查找依赖实例并注入到需要的地方。

注入方式有两种：

构造器注入（推荐）

@Controller('users')
export class UserController {
  constructor(private readonly userService: UserService) {}
}

依赖通过构造函数参数注入。

注入时机在实例化类时完成。

优点：清晰、类型安全、方便测试。

属性注入

@Controller('users')
export class UserController {
  @Inject(UserService)
  private readonly userService: UserService;
}

通过 @Inject() 装饰器显式注入依赖。

一般在特殊场景下使用（如循环依赖）。

两种方式的效果一致，但构造器注入是官方推荐的写法。

模块化结构（Module）

每个 Nest 模块通常包含以下部分：

组成部分	作用
Controller	负责接收请求、解析参数、返回响应
Service	负责业务逻辑处理（如数据库操作、第三方接口调用）
DTO	定义请求/响应的数据结构与类型验证
Entities	定义数据库表对应的实体类
Module	将相关的 controller、service、entity 等组织在一起，形成可复用模块

模块文件示例：

@Module({
  controllers: [UserController],
  providers: [UserService],
  exports: [UserService],
})
export class UserModule {}

应用启动流程

Nest 应用启动后会经历以下过程：

从 AppModule 开始作为根模块；
初始化 IoC 容器；
加载所有模块（包括其 controller、service 等）；
注册所有路由；
启动 HTTP 服务器，开始监听请求。

bootstrap() --> 初始化 IoC 容器 --> 注册模块与控制器 --> 启动服务

MVC 模式在 Nest 中的体现

Nest 框架的整体思想与经典的 MVC（Model-View-Controller） 架构一致：

层级	在 Nest 中的对应	主要职责
Model（模型层）	Entity + Repository + Service	处理业务逻辑和数据存取
View（视图层）	通常是 JSON 响应（也可使用模板引擎）	展示结果
Controller（控制层）	Controller	接收请求、调用 Service、返回响应

Client --> Controller(接收参数) --> Service(业务逻辑) --> Repository(数据库操作)
      --> Service(返回结果) --> Controller(响应客户端)

CLI 配置文件

完整的配置文件

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://json.schemastore.org/nest-cli.json",
  "$comment": "https://docs.nestjs.com/cli/monorepo#cli-properties",
  "definitions": {
    "CompilerOptions": {
      "$comment": "https://docs.nestjs.com/cli/monorepo#global-compiler-options",
      "type": "object",
      "description": "A map with keys specifying compiler options and values specifying the option setting. See https://docs.nestjs.com/cli/monorepo#global-compiler-options for details",
      "default": {},
      "properties": {
        "tsConfigPath": {
          "$comment": "https://github.com/nestjs/nest-cli/blob/master/lib/compiler/defaults/webpac-defaults.ts",
          "default": "tsconfig.build.json",
          "type": "string",
          "description": "(monorepo only) Points at the file containing the tsconfig.json settings that will be used when nest build or nest start is called without a project option (e.g., when the default project is built or started). 'nest build' will not work as expected without this file."
        },
        "builder": {
          "anyOf": [
            {
              "$comment": "https://github.com/nestjs/nest-cli/blob/master/commands/build.command.ts",
              "default": "tsc",
              "type": "string",
              "enum": ["tsc", "webpack", "swc"],
              "description": "Builder to be used (tsc, webpack, swc). For details on how to configure `SWC` see https://docs.nestjs.com/recipes/swc#getting-started"
            },
            {
              "type": "object",
              "properties": {
                "type": {
                  "$comment": "https://github.com/nestjs/nest-cli/blob/master/commands/build.command.ts",
                  "default": "tsc",
                  "type": "string",
                  "enum": ["tsc", "webpack", "swc"],
                  "description": "Builder to be used (tsc, webpack, swc). For details on how to configure `SWC` see https://docs.nestjs.com/recipes/swc#getting-started"
                },
                "options": {
                  "type": "object",
                  "properties": {
                    "outDir": {
                      "type": "string",
                      "description": "The directory to output files."
                    },
                    "filenames": {
                      "type": "array",
                      "items": {
                        "type": "string"
                      },
                      "description": "Array of filenames to be included."
                    },
                    "sync": {
                      "type": "boolean",
                      "description": "Whether to synchronize files or not."
                    },
                    "extensions": {
                      "type": "array",
                      "items": {
                        "type": "string"
                      },
                      "description": "Array of file extensions to be considered."
                    },
                    "copyFiles": {
                      "type": "boolean",
                      "description": "Whether to copy files or not."
                    },
                    "includeDotfiles": {
                      "type": "boolean",
                      "description": "Whether to include dotfiles or not."
                    },
                    "quiet": {
                      "type": "boolean",
                      "description": "Whether to suppress logs or not."
                    },
                    "watch": {
                      "type": "boolean",
                      "description": "Whether to watch files for changes or not."
                    },
                    "swcrcPath": {
                      "type": "string",
                      "description": "Path to SWC config file to use."
                    }
                  }
                }
              }
            }
          ]
        },
        "typeCheck": {
          "$comment": "https://github.com/nestjs/nest-cli/blob/master/commands/build.command.ts",
          "default": false,
          "type": "boolean",
          "description": "If true, enable type checking (when SWC is used). See https://docs.nestjs.com/recipes/swc#type-checking for details."
        },
        "webpack": {
          "$comment": "https://github.com/nestjs/nest-cli/blob/master/commands/build.command.ts",
          "default": false,
          "type": "boolean",
          "description": "If true, use webpack compiler (deprecated option, use `builder` instead). If false or not present, use tsc. In monorepo mode, the default is true (use webpack), in standard mode, the default is false (use tsc). See https://docs.nestjs.com/cli/monorepo#cli-properties for details."
        },
        "webpackConfigPath": {
          "$comment": "https://github.com/nestjs/nest-cli/blob/master/commands/build.command.ts",
          "default": "webpack.config.js",
          "type": "string",
          "description": "Points at a webpack options file. If not specified, Nest looks for the file webpack.config.js."
        },
        "plugins": {
          "$comment": "https://docs.nestjs.com/openapi/cli-plugin#using-the-cli-plugin",
          "default": [],
          "type": "array",
          "items": {
            "$ref": "#/definitions/PluginItems"
          }
        },
        "assets": {
          "$comment": "https://docs.nestjs.com/cli/monorepo#assets",
          "default": [],
          "type": "array",
          "items": {
            "$ref": "#/definitions/AssetsOptions"
          },
          "description": "Enables automatically distributing non-TypeScript assets whenever a compilation step begins (asset distribution does not happen on incremental compiles in --watch mode). Accept glob-like string and object. See https://docs.nestjs.com/cli/monorepo#assets for details."
        },
        "watchAssets": {
          "default": false,
          "type": "boolean",
          "description": "If true, run in watch-mode, watching all non-TypeScript assets. Setting watchAssets in a top-level compilerOptions property overrides any watchAssets settings within the assets property."
        },
        "deleteOutDir": {
          "type": "boolean",
          "default": false,
          "description": "If true, whenever the compiler is invoked, it will first remove the compilation output directory (as configured in tsconfig.json, where the default is ./dist)."
        },
        "manualRestart": {
          "type": "boolean",
          "default": false,
          "description": "If true, enables the shortcut `rs` to manually restart the server."
        }
      },
      "additionalProperties": false
    },
    "AssetsOptions": {
      "$comment": "https://docs.nestjs.com/cli/monorepo#assets",
      "type": ["string", "object"],
      "description": "For finer control, the element can be object.",
      "properties": {
        "include": {
          "type": "string",
          "description": "Glob-like file specifications for the assets to be distributed."
        },
        "exclude": {
          "type": "string",
          "description": "Glob-like file specifications for the assets to be excluded from the include list."
        },
        "outDir": {
          "type": "string",
          "description": "A string specifying the path (relative to the root folder) where the assets should be distributed. Defaults to the same output directory configured for compiler output."
        },
        "watchAssets": {
          "type": "boolean",
          "description": "If true, run in watch mode watching specified assets. Setting watchAssets in a top-level compilerOptions property overrides any watchAssets settings within the assets property."
        }
      },
      "additionalProperties": false
    },
    "GenerateOptions": {
      "$comment": "https://docs.nestjs.com/cli/monorepo#global-generate-options",
      "type": "object",
      "description": "A map with keys specifying global generate options and values specifying the option setting. See https://docs.nestjs.com/cli/monorepo#global-generate-options for details",
      "properties": {
        "spec": {
          "$ref": "#/definitions/GenerateSpecOptions"
        },
        "flat": {
          "$ref": "#/definitions/GenerateFlatOptions"
        },
        "baseDir": {
          "$ref": "#/definitions/GenerateBaseDirOptions"
        }
      },
      "default": {},
      "additionalProperties": false
    },
    "GenerateFlatOptions": {
      "$comment": "https://docs.nestjs.com/cli/monorepo#global-generate-options",
      "type": "boolean",
      "default": false,
      "description": "If true, all generate commands will generate a flat structure"
    },
    "GenerateSpecOptions": {
      "$comment": "https://docs.nestjs.com/cli/monorepo#global-generate-options",
      "type": ["boolean", "object"],
      "description": "If the value is boolean, a value of true enables spec generation by default and a value of false disables it. A flag passed on the CLI command line overrides this setting, as does a project-specific generateOptions setting (more below). If the value is an object, each key represents a schematic name, and the boolean value determines whether the default spec generation is enabled / disabled for that specific schematic. See https://docs.nestjs.com/cli/monorepo#global-generate-options for details.",
      "properties": {
        "application": {
          "type": "boolean",
          "description": "Generate spec file for application schematics or not."
        },
        "class": {
          "type": "boolean",
          "description": "Disable spec file generation for class schematics."
        },
        "cl": {
          "type": "boolean",
          "description": "Alias for class"
        },
        "configuration": {
          "type": "boolean",
          "description": "Generate spec file for configuration schematics or not."
        },
        "config": {
          "type": "boolean",
          "description": "Alias for configuration"
        },
        "controller": {
          "type": "boolean",
          "description": "Generate spec file for controller schematics or not."
        },
        "co": {
          "type": "boolean",
          "description": "Alias for controller"
        },
        "decorator": {
          "type": "boolean",
          "description": "Generate spec file for decorator schematics or not."
        },
        "d": {
          "type": "boolean",
          "description": "Alias for decorator"
        },
        "filter": {
          "type": "boolean",
          "description": "Generate spec file for filter schematics or not."
        },
        "f": {
          "type": "boolean",
          "description": "Alias for filter"
        },
        "gateway": {
          "type": "boolean",
          "description": "Generate spec file for gateway schematics or not."
        },
        "ga": {
          "type": "boolean",
          "description": "Alias for gateway"
        },
        "guard": {
          "type": "boolean",
          "description": "Generate spec file for guard schematics or not."
        },
        "gu": {
          "type": "boolean",
          "description": "Alias for guard"
        },
        "interceptor": {
          "type": "boolean",
          "description": "Generate spec file for interceptor schematics or not."
        },
        "in": {
          "type": "boolean",
          "description": "Alias for interceptor"
        },
        "interface": {
          "type": "boolean",
          "description": "Generate spec file for interface schematics or not."
        },
        "middleware": {
          "type": "boolean",
          "description": "Generate spec file for middleware schematics or not."
        },
        "mi": {
          "type": "boolean",
          "description": "Alias for middleware"
        },
        "module": {
          "type": "boolean",
          "description": "Generate spec file for module schematics or not."
        },
        "mo": {
          "type": "boolean",
          "description": "Alias for module"
        },
        "pipe": {
          "type": "boolean",
          "description": "Generate spec file for pipe schematics or not."
        },
        "pi": {
          "type": "boolean",
          "description": "Alias for pipe"
        },
        "provider": {
          "type": "boolean",
          "description": "Generate spec file for provider schematics or not."
        },
        "pr": {
          "type": "boolean",
          "description": "Alias for provider"
        },
        "resolver": {
          "type": "boolean",
          "description": "Generate spec file for resolver schematics or not."
        },
        "r": {
          "type": "boolean",
          "description": "Alias for resolver"
        },
        "service": {
          "type": "boolean",
          "description": "Generate spec file for service schematics or not."
        },
        "s": {
          "type": "boolean",
          "description": "Alias for resolver"
        },
        "library": {
          "type": "boolean",
          "description": "Generate spec file for library schematics or not."
        },
        "lib": {
          "type": "boolean",
          "description": "Alias for library"
        },
        "sub-app": {
          "type": "boolean",
          "description": "Generate spec file for sub-app schematics or not."
        },
        "app": {
          "type": "boolean",
          "description": "Alias for sub-app"
        },
        "resource": {
          "type": "boolean",
          "description": "Generate spec file for resource schematics or not."
        },
        "res": {
          "type": "boolean",
          "description": "Alias for resource"
        }
      },
      "additionalProperties": false
    },
    "GenerateBaseDirOptions": {
      "type": "string",
      "default": "",
      "description": "Base directory"
    },
    "ProjectConfiguration": {
      "type": "object",
      "properties": {
        "type": {
          "type": "string"
        },
        "root": {
          "type": "string"
        },
        "entryFile": {
          "type": "string"
        },
        "sourceRoot": {
          "type": "string"
        },
        "compilerOptions": {
          "$ref": "#/definitions/CompilerOptions"
        },
        "generateOptions": {
          "$ref": "#/definitions/GenerateOptions"
        }
      },
      "additionalProperties": false
    },
    "PluginItems": {
      "$comment": "https://docs.nestjs.com/openapi/cli-plugin#using-the-cli-plugin",
      "type": ["string", "object"],
      "properties": {
        "name": {
          "type": "string",
          "description": "The npm package name of the cli plugin, eg @nestjs/swagger."
        },
        "options": {
          "anyOf": [
            {
              "$ref": "#/definitions/PluginOptions"
            },
            {
              "$ref": "#/definitions/GraphQLPluginOptions"
            },
            {
              "$ref": "#/definitions/SwaggerPluginOptions"
            }
          ]
        }
      }
    },
    "PluginOptions": {
      "type": "object",
      "properties": {
        "introspectComments": {
          "type": "boolean",
          "default": true,
          "description": "If set to true, plugin will generate descriptions and example values for properties based on comments."
        }
      }
    },
    "GraphQLPluginOptions": {
      "$comment": "https://docs.nestjs.com/graphql/cli-plugin#using-the-cli-plugin",
      "type": "object",
      "properties": {
        "typeFileNameSuffix": {
          "type": "array",
          "default": [".input.ts", ".args.ts", ".entity.ts", ".model.ts"],
          "description": "(GraphQL Only) GraphQL types files suffix. Default value: ['.input.ts', '.args.ts', '.entity.ts', '.model.ts']. See https://docs.nestjs.com/graphql/cli-plugin#using-the-cli-plugin for details."
        }
      }
    },
    "SwaggerPluginOptions": {
      "$comment": "https://docs.nestjs.com/openapi/cli-plugin#using-the-cli-plugin",
      "type": "object",
      "properties": {
        "dtoFileNameSuffix": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "default": [".dto.ts", ".entity.ts"],
          "description": "(Swagger Only) DTO (Data Transfer Object) files suffix. Default value: ['.dto.ts', '.entity.ts']. See https://docs.nestjs.com/openapi/cli-plugin#using-the-cli-plugin for details"
        },
        "controllerFileNameSuffix": {
          "type": "string",
          "default": ".controller.ts",
          "description": "(Swagger Only) Controller files suffix. See https://docs.nestjs.com/openapi/cli-plugin#using-the-cli-plugin for details"
        },
        "classValidatorShim": {
          "type": "boolean",
          "default": true,
          "description": "(Swagger Only) If set to true, the module will reuse class-validator validation decorators (e.g. @Max(10) will add max: 10 to schema definition). See https://docs.nestjs.com/openapi/cli-plugin#using-the-cli-plugin for details"
        },
        "dtoKeyOfComment": {
          "type": "string",
          "default": "description",
          "description": "(Swagger Only) The property key to set the comment text to on ApiProperty. See https://docs.nestjs.com/openapi/cli-plugin#using-the-cli-plugin for details"
        },
        "controllerKeyOfComment": {
          "type": "string",
          "default": "description",
          "description": "(Swagger Only) The property key to set the comment text to on ApiOperation. See https://docs.nestjs.com/openapi/cli-plugin#using-the-cli-plugin for details"
        }
      }
    }
  },
  "properties": {
    "language": {
      "type": "string",
      "default": "ts"
    },
    "collection": {
      "type": "string",
      "default": "@nestjs/schematics",
      "description": "Points at the collection of schematics used to generate components. you generally should not change this value."
    },
    "sourceRoot": {
      "$comment": "https://github.com/nestjs/nest-cli/blob/master/actions/add.action.ts",
      "type": "string",
      "default": "src",
      "description": "Points at the root of the source code for the single project in standard mode structures, or the default project in monorepo mode structures."
    },
    "entryFile": {
      "$comment": "https://github.com/nestjs/nest-cli/blob/master/actions/start.action.ts",
      "type": "string",
      "default": "main",
      "description": "The entry file where 'nest start' work with. Default to 'main'."
    },
    "monorepo": {
      "type": "boolean",
      "description": "(monorepo only) For a monorepo mode structure, this value is always true.",
      "default": false
    },
    "root": {
      "type": "string",
      "description": "(monorepo only) Points at the project root of the default project.",
      "default": ""
    },
    "compilerOptions": {
      "$ref": "#/definitions/CompilerOptions"
    },
    "generateOptions": {
      "$ref": "#/definitions/GenerateOptions"
    },
    "projects": {
      "type": "object",
      "additionalProperties": {
        "$ref": "#/definitions/ProjectConfiguration"
      },
      "default": {}
    },
    "defaultLibraryPrefix": {
      "type": "string",
      "description": "Default import prefix for newly generated libraries.",
      "default": "@app"
    }
  },
  "title": "Nest CLI configuration",
  "type": "object"
}

中文版

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://json.schemastore.org/nest-cli.json",
  "$comment": "https://docs.nestjs.com/cli/monorepo#cli-properties（备注：NestJS CLI monorepo 模式下属性说明）",
  "definitions": {
    "CompilerOptions": {
      "$comment": "https://docs.nestjs.com/cli/monorepo#global-compiler-options（全局编译选项）",
      "type": "object",
      "description": "一个映射对象，其键指定编译器选项，值指定该选项的设置。详细说明见 NestJS 文档。",
      "default": {},
      "properties": {
        "tsConfigPath": {
          "$comment": "tsconfig.json 文件路径（monorepo 专用）",
          "default": "tsconfig.build.json",
          "type": "string",
          "description": "指向包含 tsconfig.json 设置的文件，当 nest build 或 nest start 在未指定 project 选项时将使用该文件。"
        },
        "builder": {
          "anyOf": [
            {
              "$comment": "构建器类型（字符串形式）",
              "default": "tsc",
              "type": "string",
              "enum": ["tsc", "webpack", "swc"],
              "description": "要使用的构建器类型（tsc、webpack、swc）。有关 SWC 配置，请参考官方文档。"
            },
            {
              "type": "object",
              "properties": {
                "type": {
                  "$comment": "构建器类型（对象形式）",
                  "default": "tsc",
                  "type": "string",
                  "enum": ["tsc", "webpack", "swc"],
                  "description": "指定构建器类型（tsc、webpack、swc）。"
                },
                "options": {
                  "type": "object",
                  "properties": {
                    "outDir": {"type": "string","description": "输出目录。"},
                    "filenames": {"type": "array","items": {"type": "string"},"description": "包含的文件名数组。"},
                    "sync": {"type": "boolean","description": "是否同步文件。"},
                    "extensions": {"type": "array","items": {"type": "string"},"description": "要考虑的文件扩展名。"},
                    "copyFiles": {"type": "boolean","description": "是否复制文件。"},
                    "includeDotfiles": {"type": "boolean","description": "是否包含隐藏文件（点文件）。"},
                    "quiet": {"type": "boolean","description": "是否静默输出日志。"},
                    "watch": {"type": "boolean","description": "是否启用文件监控模式。"},
                    "swcrcPath": {"type": "string","description": "SWC 配置文件路径。"}
                  }
                }
              }
            }
          ]
        },
        "typeCheck": {"$comment":"类型检查","default": false,"type": "boolean","description": "如果为 true，则启用类型检查（仅 SWC 构建器有效）。"},
        "webpack": {"$comment":"Webpack 选项（已废弃）","default": false,"type": "boolean","description": "如果为 true，则使用 webpack 编译器（已废弃，建议使用 builder）。"},
        "webpackConfigPath": {"$comment":"Webpack 配置路径","default": "webpack.config.js","type": "string","description": "Webpack 配置文件路径，如果未指定，则默认查找 webpack.config.js。"},
        "plugins": {"$comment":"CLI 插件配置","default": [],"type": "array","items": {"$ref": "#/definitions/PluginItems"}},
        "assets": {"$comment":"非 TypeScript 资源配置","default": [],"type": "array","items": {"$ref": "#/definitions/AssetsOptions"},"description": "启用在每次编译开始时自动分发非 TypeScript 资源，可使用 glob 字符串或对象。"},
        "watchAssets": {"default": false,"type": "boolean","description": "如果为 true，则监控所有非 TypeScript 资源。"},
        "deleteOutDir": {"type": "boolean","default": false,"description": "如果为 true，则每次编译前删除输出目录。"},
        "manualRestart": {"type": "boolean","default": false,"description": "如果为 true，则启用 rs 命令手动重启服务器。"}
      },
      "additionalProperties": false
    },
    "AssetsOptions": {
      "$comment": "资源选项配置（可为字符串或对象）",
      "type": ["string","object"],
      "description": "指定要分发的资源文件，可为字符串或对象。",
      "properties": {
        "include": {"type": "string","description": "匹配要分发的资源文件的 glob 模式。"},
        "exclude": {"type": "string","description": "排除的资源文件 glob 模式。"},
        "outDir": {"type": "string","description": "分发目标目录（相对于根目录），默认同编译输出目录。"},
        "watchAssets": {"type": "boolean","description": "如果为 true，则监控指定资源文件。"}
      },
      "additionalProperties": false
    },
    "GenerateOptions": {
      "$comment": "生成命令全局选项",
      "type": "object",
      "description": "全局 generate 命令选项映射。",
      "properties": {
        "spec": {"$ref": "#/definitions/GenerateSpecOptions"},
        "flat": {"$ref": "#/definitions/GenerateFlatOptions"},
        "baseDir": {"$ref": "#/definitions/GenerateBaseDirOptions"}
      },
      "default": {},
      "additionalProperties": false
    }
  },
  "properties": {
    "language": {"type": "string","default": "ts"},
    "collection": {"type": "string","default": "@nestjs/schematics","description": "指定用于生成组件的 schematics 集合，通常无需更改。"},
    "sourceRoot": {"type": "string","default": "src","description": "源代码根目录，标准模式为单项目根，monorepo 模式为默认项目根。"},
    "entryFile": {"type": "string","default": "main","description": "入口文件，nest start 将从此文件启动应用。"},
    "monorepo": {"type": "boolean","default": false,"description": "仅 monorepo 模式使用，值为 true。"},
    "root": {"type": "string","default": "","description": "默认项目根目录（monorepo 模式）。"},
    "compilerOptions": {"$ref": "#/definitions/CompilerOptions"},
    "generateOptions": {"$ref": "#/definitions/GenerateOptions"},
    "projects": {"type": "object","additionalProperties": {"$ref": "#/definitions/ProjectConfiguration"},"default": {}},
    "defaultLibraryPrefix": {"type": "string","default": "@app","description": "新生成库默认 import 前缀。"}
  },
  "title": "Nest CLI 配置（中文翻译）",
  "type": "object"
}

打包为单个文件

pkg 可以把 Node.js 项目连同 Node 运行时一起打包成一个 exe / bin 文件，支持 Windows / Linux / macOS。

注意：

pkg 不支持动态 require()，Nest 的一些模块（例如动态加载模块、外部 JSON 配置）可能需要调整。
一些本地依赖文件可能需要手动指定 assets 打包。

@vercel/ncc 可以把 Node.js 项目打包成单个文件。

步骤

安装 ncc：

npm i -D @vercel/ncc

编译 Nest 项目：

nest build

用 ncc 打包：

ncc build dist/main.js -o dist-bundle

运行：

node dist-bundle/index.js

特点：

支持大多数 Node.js 模块
会把依赖打包进一个 JS 文件
可结合 PM2 或 Docker 部署

Node 本身对模块是按需加载的，所以一般不需要把 node_modules 全部打包。

打包成单个 JS 文件（比如用 ncc）的主要好处是 提升启动性能，因为不再有大量的文件 I/O 去加载各个模块，而是直接加载一个捆绑好的文件。

对于 Nest 应用来说，单文件打包对部署也更方便（少文件拷贝），而且依赖管理仍然可以通过 package.json 来维护。

打包后的文件中可能有不少“可读性成本”：注释、空行、长变量名。而这些对运行没啥用，完全可以压。

ncc 有 --minify，会把 bundle 进一步压一遍（去注释、压缩空白、缩短一些结构）。

ncc build dist/main.js -o dist-bundle --minify

ncc 输出后，再用 terser 压一次，效果一般比 ncc 自带更明显（尤其去注释、压 whitespace）。

npx terser dist-bundle/index.js \
  -c passes=2 \
  -m \
  --comments false \
  -o dist-bundle/index.min.js

生成的 dist-bundle/index.js 就是 独立启动的单文件

依赖按需内联，提高启动速度，同时仍保留 Node 的模块解析优势