feat(v2): allow home page for docs

[lex111]

Motivation

I am really excited to close all three of the listed PRs, finally this issue, which our users constantly mention, will be closed! 😝

Resolve #2507
Resolve #2567
Resolve #1973

Related issue on Canny - https://docusaurus.canny.io/admin/board/feature-requests/p/home-page-for-docs

Yes, indeed, although there are not many changes, the complexity of the code increases, but this is all because to cover all use cases:

• Docs without versioning
• Docs with versioning
• Docs-only mode
• Using existing document as home page
• Using special-purpose document (default is "_index") as home page
• Possibility to have the own docs page (thereby override the default home page, this may be useful in versioning docs)

Have you read the Contributing Guidelines on pull requests?

Yes

Test Plan

See docs and preview (eg. https://deploy-preview-2652--docusaurus-2.netlify.app/docs/)

P.S. You can see in snapshots diff that the sorting of routes has been changed, that's actually how it should be (so you don't have to worry about that).

docusaurus/packages/docusaurus/src/server/plugins/index.ts

Lines 103 to 105 in 1f00d15

	// Sort the route config. This ensures that route with nested
	// routes are always placed last.
	sortConfig(pluginsRouteConfigs);

Related PRs

(If this PR adds or changes functionality, please take some time to update the docs at https://github.com/facebook/docusaurus, and link to your PR here.)

[docusaurus-bot]

Deploy preview for docusaurus-2 ready!

Built with commit 92d16c7

https://deploy-preview-2652--docusaurus-2.netlify.app

[lex111]

It is strange why Travis CI fails, I have everything OK on my local machine.
@yangshun could please you force it to restart?

It's all right.

[lex111]

Again, there seems to be a problem with snapshots being different in local (dev) and test (CI) environments. I take it this is due to the asynchronous processing of routes, perhaps it is worth sorting routes to achieve the same result?

[lex111]

Even in my fork, tests with changes to this PR successfully pass. I can’t understand why in this (original) repo does not pass the tests.

Test Suites: 47 passed, 47 total
Tests:       267 passed, 267 total
Snapshots:   123 passed, 123 total
Time:        134.669s
Ran all test suites.
Done in 136.01s.

[lex111]

Hell yeah, I added sorting for child routes and tests began to pass for CI. Now we have the same result on all environments.

[benmccann]

Thanks for this! Just FYI, this PR will need a rebase

The other thing that will help us a lot with the homepage is #2537

[yangshun]

Should we add this feature into the examples too?

[lex111]

Should we add this feature into the examples too?

Do you mean init template?

[yangshun]

Oh yes the templates. I think we should add useful defaults to the templates.