# new NestBootstraper()
The NestBootstraper class provides a chainable API for configuring
a NestJS application instance. It includes built-in methods for enabling
CORS, Helmet security, Swagger documentation, global pipes, filters,
interceptors, and starting the server.
This class promotes consistency and reduces repetitive setup code across multiple NestJS projects.
A fluent, static bootstrap class for initializing and configuring a NestJS application.
Example
```ts
import { NestFactory } from "@nestjs/core";
import { AppModule } from "./app.module";
import { MyLogger } from "./MyLogger";
import { NestBootstraper } from "@decaf-ts/for-nest";
async function bootstrap() {
const app = await NestFactory.create(AppModule);
await NestBootstraper
.initialize(app)
.enableLogger(new MyLogger())
.enableCors(["http://localhost:4200"])
.useHelmet()
.setupSwagger({
title: "OpenAPI by TradeMark™",
description: "TradeMark™ API documentation",
version: "1.0.0",
path: "api",
persistAuthorization: true,
topbarBgColor: "#2C3E50",
topbarIconPath: "/assets/logo.svg",
faviconPath: "/assets/favicon.ico"
})
.useGlobalFilters()
.useGlobalPipes(...)
.useGlobalInterceptors(...)
.start(3000);
}
bootstrap();
```Members
# static logger
Ensures that a valid Logger instance is always available
for logging bootstrap-related messages.
Returns the current logger instance, creating a default one if not set.
Methods
# static enableCors(originsopt, allowMethodsopt) → {NestBootstraper}
Allows defining either a wildcard origin ("*") or a list of allowed origins.
Automatically accepts local development requests and those without origin headers.
Throws a CorsError for unauthorized origins.
Enables Cross-Origin Resource Sharing (CORS) for the application.
Parameters:
| Name | Type | Attributes | Default | Description |
|---|---|---|---|---|
origins |
'*'
|
Array.<string>
|
<optional> |
[] | List of allowed origins or |
allowMethods |
Array.<string>
|
<optional> |
['GET', 'POST', 'PUT', 'DELETE'] | Allowed HTTP methods. |
Returns the class for chaining configuration.
# static enableLogger(customLoggeropt) → {NestBootstraper}
If a custom logger is provided, it replaces the default logger. Otherwise,
a new logger named "NestBootstrap" is used. This logger is also registered
with the NestJS application.
Enables or replaces the global logger for the NestJS application.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
customLogger |
Logger
|
<optional> |
Optional custom logger instance. |
Returns the class for chaining.
# static initialize(app) → {NestBootstraper}
Binds the provided NestJS app instance to the bootstrapper, enabling chained configuration methods.
Initializes the bootstrapper with a given NestJS application.
Parameters:
| Name | Type | Description |
|---|---|---|
app |
INestApplication
|
The NestJS application instance to initialize. |
Returns the class for chaining configuration methods.
# static setupSwagger(options) → {NestBootstraper}
Uses the SwaggerBuilder utility to configure API documentation
with detailed customization for title, version, paths, and colors.
Swagger is automatically exposed at the configured path.
Configures and initializes Swagger UI for API documentation.
Parameters:
| Name | Type | Description |
|---|---|---|
options |
SwaggerSetupOptions
|
Swagger configuration options. |
Returns the class for chaining configuration.
# async static start(portopt, hostopt, logopt) → {Promise.<void>}
Listens on the specified port and optionally a host. Once started, logs the application URL for easy access. The startup process resolves once the application is successfully running.
Starts the NestJS application and binds it to the given port and host.
Parameters:
| Name | Type | Attributes | Default | Description |
|---|---|---|---|---|
port |
number
|
<optional> |
3000 | Port number to listen on. |
host |
string
|
<optional> |
Optional host or IP address to bind to. |
|
log |
boolean
|
<optional> |
true | Whether to log the application URL upon startup. |
Resolves once the application starts successfully.
Promise.<void>
# static useGlobalFilters(…filters)
If no filters are provided, it automatically registers a default
set of standard exception filters for common error types like
HttpException, ValidationException, ConflictException, and others.
Registers one or more global exception filters.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
filters |
Array.<ExceptionFilter>
|
<repeatable> |
Optional filters to apply globally. |
# static useGlobalInterceptors(…interceptors) → {NestBootstraper}
Interceptors allow advanced request/response manipulation such as serialization, logging, or transformation. Multiple interceptors can be added for modular configuration.
Registers global interceptors for request and response transformation.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
interceptors |
Array.<NestInterceptor>
|
<repeatable> |
Interceptor instances to register. |
Returns the class for chaining configuration.
# static useGlobalPipes(…pipes) → {NestBootstraper}
Enables request payload validation and transformation globally across the entire NestJS application. Multiple pipes can be chained together for modular input validation.
Registers one or more global validation pipes.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
pipes |
Array.<PipeTransform>
|
<repeatable> |
Pipe instances to register globally. |
Returns the class for chaining.
# static useHelmet(optionsopt) → {NestBootstraper}
Dynamically loads the helmet package if available and registers it
as middleware to improve HTTP header security. If not installed, logs a warning
and continues execution without throwing errors.
Applies the Helmet middleware for enhanced security.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
options |
Record.<string, any>
|
<optional> |
Optional configuration passed to Helmet. |
Returns the class for chaining configuration.