Scroll to anchor in `router.scrollBehavior` doesn't work #213

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Bug report

https://github.com/saberland/saber/blob/61992cbcff3ed552aa90e6bff1cf320e1d35da82/packages/saber/vue-renderer/app/router.js#L68-L87

The code attempts to scroll to the anchor if to.hash exists and the anchor can be found. But the scroll never happens.

Version

0.6.4

Steps to reproduce

about.md:

[Hello](./hello.md#world)

hello.md:

# World

Lorem ipsum...

Then click the link in about.md.

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What is expected?

Page scrolled to the title World.

What is actually happening?

Page scrolled to the top (default behavior).

Other relevant information

1. If to.hash only contains ASCII characters, the hash before and after escaping are the same. If it contains non-ASCII characters (e.g. CJK characters), escaping the hash will produce a selector matching nothing (assuming header's id is generated in standard behavior).

Possible solution: Use decodeURIComponent(to.hash) instead of window.CSS.escape(to.hash)

2. Even if the selector is valid, document.querySelector(hash) still matches nothing, thus the scroll won't trigger. Chances are page is not loaded at that time.

Possible solution: Move the codition statement to a hook like afterPageLoad or use other methods (can only come up with setTimeout(condition, 0))

• Result of running saber -v: cli.js/0.6.4 win32-x64 node-v12.3.1
• Browser version (optional): Google Chrome 76.0.3800.0 (64-bit)
• Is Saber a global or local install? Local
• Which package manager did you use for the install? Yarn
• Does this issue occur when all plugins are disabled? Yes