Add option directorySlash to redirect with slash

[bjornharrtell]

Aims to implement support for #81.

[3imed-jaberi]

LGTM 👍, can you write the test !!

Suggested change

	ctx.redirect(ctx.request.path + '/')
	ctx.redirect(`${ctx.request.path}/`)

[niftylettuce]

I don't know about this - I think just using koa-no-trailing-slash package is fine.

[liqi0816]

Hi @niftylettuce Would you please reconsider this feature? koa-send is behaving significantly differently from (the default of) other major static servers which is confusing.

When accessing /dirname:

• Nginx: 301 redirect to /dirname/ doc
• Apache: 301 redirect to /dirname/ doc with reasoning
• npm http-server: 302 redirect to /dirname/
• npm node-static: 301 redirect to /dirname/

...and

• koa-send: no redirection and breaks any further relative paths.

I feel it reasonable to expect a built-in redirection since that is other static servers do. Monkey patching works, but is annoying.

[liqi0816]

I don't know about this - I think just using koa-no-trailing-slash package is fine.

For anyone who is interested, koa-no-trailing-slash removes the trailing slash instead of adding one, and has been archived.

The library that adds a trailing slash is koa-add-trailing-slashes, except it does not check whether the path is a directory or not and adds a slash anyway, so still something will break.

[niftylettuce]

@liqi0816 can you just add a PR to koa-add-trailing-slashes or write your own package for this?

[liqi0816]

I can, but may I know if there is a reason koa-send need to be different from other static servers? It is breaking people's assumptions.

[liqi0816]

Just verified express.static also does a 301 redirect. https://github.com/expressjs/serve-static/blob/master/index.js#L182

I understand koa is not meant to be compatible with express or whatever other servers, but at least people are expecting similar functionalities. It would be really great if koa-send aligns with them.