How do wildcard and optional route segments work in NestJS?

Q: How do wildcard and optional route segments work in NestJS?

// Wildcard — matches any characters in a single segment @Get('ab*cd') // matches abXcd, ab_cd, ab123cd // Catch-all wildcard @Get('files/*') // matches files/a/b/c/d // Optional param — Express style (append ?) @Get(':id?') // matches /users AND /users/42 (id is undefined if absent) // Real-world: serve SPA for all unknown routes @Get('*') serveApp(@Res() res: Response) { res.sendFile(join(__dirname, '..', 'public', 'index.html')); } // IMPORTANT: declare specific routes BEFORE wildcard routes @Get('export') // must come before :id export() {} @Get(':id') // catches everything else findOne() {} Declare specific literal routes before wildcard param routes — NestJS matches in declaration order on Express. Fastify uses a radix tree that automatically prefers static routes over parametric ones. @Get('*') is a catch-all and should always be the last route in a controller. Optional params with ? make the segment optional — the param value is undefined when absent. Always test wildcard behavior on both Express and Fastify if you plan to switch platforms.

Difficulty: 5/10

wildcard routes, optional parameters, routing precedence

NestJS uses path-to-regexp under Express. Wildcards match any segment using * and optional params are declared with a trailing ?. Wildcard routes must be declared after specific routes because NestJS matches routes in declaration order on Express. Fastify uses a radix tree that prefers static segments over parametric ones.

Wildcard and optional route patterns

Wildcard routing rules:

1
Declare specific literal routes before wildcard param routes — NestJS matches in declaration order on Express.
2
Fastify uses a radix tree that automatically prefers static routes over parametric ones.
3
@Get('*') is a catch-all and should always be the last route in a controller.
4
Optional params with ? make the segment optional — the param value is undefined when absent.
5
Always test wildcard behavior on both Express and Fastify if you plan to switch platforms.

Scenario Questions

0-2 years experience

Follow-up Questions