Attempting to reproduce the bug from NestJS issue 14822

Optional values work when including other optional parts.

The route where the slash comes before the capture group (sample2/{:exampleParam}') requires the request url to also end with a trailing slash. The route where the slash is in the capture group ('sample{/:exampleParam}') works as I expected, no trailing slash or optional trailing slash. (I haven't tested on a previous NestJS + Express version.)

The sample 3 route with multiple optional segments works, as long as a value exists for the first optional segment before the secone optional segment is hit. E.g., sample3//lastname doesn't work but sample3/first/last and other variations do, with and without the trailing space.

Sample 4 works the same as 3, but nests the optional segments allowing for both to be empty (sample4//last or sample4//)

Express + ?

Use a route with an optional parameter capture using :example? instead of {:example} will lead to an error similar to below. This project was using pnpm.

[Nest] 1308807 - 06/13/2025, 6:06:57 PM ERROR [LegacyRouteConverter] Unsupported route path: "/sample/:exampleParam?". In previous versions, the symbols ?, , and + were used to denote optional or repeating path parameters. The latest version of "path-to-regexp" now requires the use of named parameters. For example, instead of using a route like /users/ to capture all routes starting with "/users", you should use /users/*path. For more details, refer to the migration guide.

TypeError: Unexpected ? at 21, expected END: https://git.new/pathToRegexpError