Routes & Decorators — Series 3

Preview — 3 of 10 questions

What distinguishes the two?

javascript

@Put(':id')   replace(@Param('id') id: string, @Body() dto: ReplaceCatDto) {}
@Patch(':id') update(@Param('id') id: string, @Body() dto: UpdateCatDto) {}

A@Put creates a resource and @Patch updates one

B@Put accepts a body while @Patch does not

CPUT replaces the resource with the representation sent, so the body is expected to be complete; PATCH applies a partial modification, so the body carries only the fields to change

DThey are interchangeable; Nest treats both identically

Why does dto arrive empty?

javascript

@Get('search')
search(@Body() dto: SearchDto) {}

ABecause @Body() only works alongside @Param()

BBecause GET requests conventionally carry no body — browsers, fetch and most HTTP clients will not send one, and intermediaries may drop it — so there is nothing for the body parser to produce; search criteria belong in the query string

CBecause Nest strips bodies from GET requests for security reasons

DBecause SearchDto needs @IsOptional() on every field

What does GET /cats/featured return?

javascript

@Controller('cats')
export class CatsController {
  @Get('featured')
  featured(@Param('id') id: string) { return typeof id; }
}

A'undefined' — the route declares no :id segment, so there is nothing to extract and the parameter is simply undefined

B'string', with id set to 'featured'

CA 400, because a declared parameter is missing from the request

DA 500, since parameter extraction fails

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