feat: nuxt 3 support

[nozomuikuta]

Replace nuxt/framework#108 with minimal spec for fast upgrade.
Sorry, I had to recreate PR because I changed my personal email settings.

---

This draft PR aims to take over nuxt/framework#103 and resolves nuxt/framework#106.

At first, for the next major release, I triaged all the open issues as below (except Renovate Dependency Dashboard (#99)).

My implementation may include some breaking changes in API, as done in nuxt/framework#103, in a way that I believe is good and beneficial enough for users. I would like to discuss with authors and community while developing this PR.

This PR doesn't aim to add Docus-powered documentation, which is handled in nuxt/framework#103, so that we can keep this PR's "done of definition" manageable.

This PR message will be modified as needed.

TODOs

• Scaffold by Nuxt module starter
• Restore LICENSE
• Restore CHANGELOG.md
• Rewrite README.md
• Restore/Modify Renovate configuration
• Restore/Modify Commitlint configuration
• Restore/Modify Husky configuration
• Restore/Modify testing
• Restore/Modify GitHub Actions
• Implement module with new features (✨), bug fixes (🔧), breaking changes (⚠️), and dropped spec (spec)
  • Feed file generation (may be blocked by add back generate hooks nuxt/nuxt#13856)
    • Atom file generation
    • JSON file generation
    • RSS file generation
  • middleware for feed SSR
  • cache time for each feed (async-cache package is deprecated, can nitro's unstorage layer be an alternative?)
  • create function for each feed
  • data passed to create function for each feed
  • ✨ common create function for all feeds
  • ✨ common data passed to create function for all feeds
  • ✨ feat: generate feed link options based on path #9
  • ✨ XML from API #70 (need spec)
  • ✨ Googlenews.xml #89 (need spec/research)
  • ✨ Namespace and custom attributes #95 (blocked by Add extra attributes on <rss> tag jpmonette/feed#98)
  • ⚠️ feed sources factory function (sources option can be a function instead of factory option)
  • ⚠️ data passed to feed sources factory function (not sure about use case, can be deprecated (?))
  • 🔧 Cannot read property 'factory' of undefined #63 (fixed by breaking change on factory option)
  • 🔧 Favicon missing when subscribing from RSS-readers. #102 (need research)

Out of Scope

• Implementation
  • router integration nuxt/nuxt#11733 (looks stale)
  • Duplicate fetches from asyncData nuxt/nuxt#10961 (looks stale)
• Documentation
  • GraphQL/Apollo example
    • If using Apollo instead of Axios? #5
    • example: add an apollo/gql example #11
  • Handle options.css nuxt/bridge#122
  • chore(deps): update all non-major dependencies nuxt/framework#62

References

• https://roe.dev/blog/creating-your-own-sitemap-module

[nozomuikuta]

👀 routes is an empty array so that no item is added to feeds. Need some configuration in somewhere else for it to work?

[nozomuikuta]

@danielroe

IMHO, it's convenient to have "typedefs": true defined in @nuxtjs/eslint-config-typescript, because it would be common to refer to other types before their definitions.

What do you think?

(note: the other 3 flags are copied from the output of yarn eslint --print-config ./src/module.ts, so I believe they are defined in somewhere in the extended configs.)

[nozomuikuta]

As of v3.3.1, Nuxt supports nitro:build:public-assets hook, which is said to be the successor to generate:done hook.

• add back generate hooks nuxt/nuxt#13856 (comment)
• https://github.com/nuxt/nuxt/releases/tag/v3.3.1

I believe now it's time to complete this PR.

@danielroe

Is it simply interchangeable, or is there difference from generate:done hook on usage?

[danielroe]

It should be interchangeable for the purpose of this module.

[nozomuikuta]

Hmm, if I'm correct, this module has to know all routes inside server route(s) to return feed file(s) as response, and I can't find the way...

Current code in my local looks like this.
I checked app instance passed via app:templates, but there doesn't seem to be information about routes 🤔

Or, am I totally taking wrong approach?

    nuxt.hook('pages:extend', (pages) => {
      sources.forEach((source, index) => {
        const { dst } = addTemplate({
          filename: `feed-${source.type}-${index}.mjs`,
          getContents: () => `
import { Feed } from 'feed'
import { defineEventHandler } from 'h3'

export default defineEventHandler(async (event) => {
  const feed = new Feed()

  feed.options = {
    generator: 'https://github.com/nuxt-community/feed-module',
  }

  ${pages.forEach((page) => `
  feed.addItem({
    title: ${page.meta?.title ?? ''},
    id: ${page.path},
    link: ${page.path},
    description: ${page.meta?.description ?? ''},
    date: new Date()
  })`.trim())}

  return feed.${source.type}()
})`.trimStart(),
          write: true // debug
        })

        addServerHandler({
          route: source.path,
          handler: dst
        })
      })

[nozomuikuta]

Another point about which I want to clarify is that, since Nuxt 3 modules are all what is called build modules in Nuxt 2, runtime code that they create can't refer to variables passed to module function itself. Then, there is no safe way to support this modules' create option which is a function, is it? Using toString method on the function may result in unexpected behavior.

[danielroe]

You can get each generated route via the prerender:generate Nitro hook. You could use that to add them to an array/Set which you then use in nitro server route. (Don't add this route with addTemplate but use the nitro.virtual vfs as the final Nitro build will happen 'after' the prerendering step.)

You're right that we advise against including runtime code in nuxt.config. Instead, I would recommend users configure this within their app.config file. You can add the typings in the module for an object with feed key so they get type support.