Chainable baseURL

[idiotWu]

Currently(v1.0.x), router.base() will always resolve to the origin of current page. For example:

const { router } = createServer();

router.base('/api'); // => http://localhost:3000/api

However, this will be counterintuitive when we code as:

const { router } = createServer('/api');

router.base('/v1'); // => http://localhost:3000/v1

Instead of getting a path of /api/v1, we got /v1 :(. So I'm wondering if we should resolve the given baseURL against current baseURL, just like the mount-paths in express apps.

CC @vincentbel

[idiotWu]

Some potential issues of chainable baseURL:

1. Syntax

Should relative paths be prefixed with '.'?

const { router } = createServer('/api');

router.base('/v1'); 
// OR
router.base('./v1');

P.S. The native URL accepts both relative and absolute paths (notice the trailing slash):

new URL('/v1', 'http://localhost:3000/api'); // => http://localhost:3000/v1
new URL('./v1', 'http://localhost:3000/api'); // => http://localhost:3000/v1
new URL('./v1', 'http://localhost:3000/api/'); // => http://localhost:3000/api/v1

2. Possible confusion

Think about the following scenario: router.base() points to another domain:

const { router } = createServer('/api'); // => http://localhost:3000/api

router.base('http://remote.com'); // => http://remote.com

[vincentbel]

@idiotWu Summary of some of our discussions:

1. Servers with different origin should use createServer, rather than router.base(because they are different servers, router.base is counter-intuitive)

// Good
const apiRouter = createServer('/api').router
const githubApiRouter = createServer('https://api.github.com').router

// Bad
const server = createServer('/api')
const apiRouter = server.router
const githubApiRouter = server.router.base('/https://api.github.com')

// Also bad
const server = createServer()
const apiRouter = server.router.base('/api')
const githubApiRouter = server.router.base('/https://api.github.com')

2. Chainable baseURL can also be used to split routes. Example: https://gist.github.com/VincentBel/6a7d35e6a2999e2aa90d065a77831bfd

Feel free to point out faults if exists.

[idiotWu]

@vincentbel so the given baseURL should be regarded as a kind of "prefixes" for the path?

Ah, we have already documented it as "prefixes":

So I think this issue is more a bug fix than a breaking feature?

[vincentbel]

@idiotWu yeah, I think we don't provide router.base as a way to create a new server in purpose. So I also think it is more a bug fix.

[idiotWu]

@vincentbel one more thing, as we've discussed, the router.base() method is designed for "prefixes", or we can say relative paths only. So should we reject all absolute paths or just throw a warning?

router.base('http://a.com'); // die or show warning?

[vincentbel]

@idiotWu I think die is better because we don't mean to support this approach.😑

[vincentbel]

and warnings are just ignored by developers. 😅

[idiotWu]

Resolved in #23 #25