fix(#3464): override permalink use the front-matter

[SukkaW]

What does it do?

The PR closes #1158, closes #1813, closes #3464

#3464 (comment)

hexo/lib/plugins/processor/post.js

Lines 123 to 126 in edef5c2

	if (data.permalink) {
	data.slug = data.permalink;
	delete data.permalink;
	}

Originally, during the processing of the post, the permalink defined in the front-matter which is data.permalink, will override data.slug and data.permalink will be deleted.

And, in post_permalink filter, data.slug will be used to get name and title property:

hexo/lib/plugins/filter/post_permalink.js

Lines 15 to 16 in edef5c2

	title: slug,
	name: typeof slug === 'string' ? basename(slug) : '',

So if I got a post: source/_posts/i-love-hexo/hello.md, I will get:

• title: i-love-hexo/hello
• name: hello

If I then defines permalink as permalink-test/hi.md, I will get:

• title: permalink-test/hi
• name: hi.

I don't know why it is designed like this. Maybe using the permalink to override the relative path under source/_posts. But it doesn't make any sense - why I have to override the relative path? I could just create required directories under source/_posts and it will be fine.

Also, the behavior of Post is different from Page, which permalink in the front-matter is truly able to override the hexo.config.permalink. And that behavior is what user really want.

So in this PR, I made a few changes toward post processor and post_permalink filter.

As the behavior of the permalink in the front-matter has changed, thus the PR is still considered as a Breaking Change

How to test

git clone -b fix-issue-3464 https://github.com/sukkaw/hexo.git
cd hexo
npm install
npm test

Screenshots

Pull request tasks

• Add test cases for the changes.
• Passed the CI test.

[SukkaW]

BREAKING CHANGES.

data.slug won't be override by data.permalink. That means data.slug will still come from the original path relative to source/_posts.

Also, a new __permalink is created to avoid overriding Post.virtual('permalink').get.

[SukkaW]

When a __permalink is detected (which is added by post processor from permalink inside the front-matter), it will be return directly.

BREAKING CHANGES:

permalink inside the front-matter is no longer controlled by hexo.config.permalink.

[coveralls]

Coverage remained the same at 97.793% when pulling 2de3e25 on SukkaW:fix-issue-3464 into edef5c2 on hexojs:master.

[curbengh]

WFM. One thing to note that is that hexo-server currently needs a trailing slash in permalink: (regardless of _config.yml or front-matter), otherwise it responds with invalid mime type; this limitation could be resolved in hexojs/hexo-server#111.