The prefix with or without trailing slash is applied erroneously to the simple API /

[MIA-Deltat1995]

The description of the bug or the rationale of your proposal

If it is configured a custom prefix and there is a API with path '/', the resulting OAS documentation is wrong.

A snippet of code for replicating the issue or showing the proposal usage if applicable

Using the prefix /prefix/ and registering the GET / the OAS is the following (see this test

lc39/tests/documentation-routes.test.js

Line 56 in 5aa4769

test('Test Fastify creation with custom prefix', async assert => {

):

Using the prefix /prefix and registering the GET / the OAS is the following (see this test

lc39/tests/documentation-routes.test.js

Line 82 in 5aa4769

test('Test Fastify creation with custom prefix without trailing slash', async assert => {

):

Note
Consider that in these tests fastify use the default settings:

• ignoreTrailingSlash: false (https://fastify.dev/docs/latest/Reference/Server/#ignoretrailingslash)
• prefixTrailingSlash: 'both' (https://fastify.dev/docs/latest/Reference/Routes/#routes-options)