Migrate to monorepo to split Vue 2 and Vue 3 packages

[nogic1008]

Related #343

Currently, the structure of this repository is as follows:

Branch	Version	Vue	Jest
master	4.x	2.x	<27
next	5.x(alpha)	3.x	<27

In Jest 27, breaking changes have came. (#344, #348, #351)
To accommodate it, this package also requires breaking changes. (and need to increment semver)

But, vue-jest@4 cannot increment because of 5.x exists.
So we should split it to another package.

If you want to keep the package name different, I don't think it is necessary to divide the version by branch. (ex. CI/CD)

@lmiller1990
Could you tell us your thoughts on the items in the "Consideration" section?

Details

Package naming & Support version

Package	Ver.	Vue ver.	Jest ver.	Description
vue-jest	4.x	2.x	<27	alias for vue2-jest@26
vue-jest	5.x(alpha)	3.x	<27	deprecate (use vue3-jest@26 instead)
vue-jest	27.x	latest (=2.x now)	27.x	alias for vue2-jest@27 now
vue2-jest	26.x	2.x	26.x	equals to vue-jest@4
vue3-jest	26.x	3.x	26.x	equals to vue-jest@5
vue2-jest	27.x	2.x	27.x
vue3-jest	27.x	3.x	27.x

Versioning

Like ts-jest, We DOES NOT use Semantic Versioning.

vue2-jest@xx.yy.zz
vue3-jest@xx.yy.zz

• xx: Equals supported Jest major version
• yy: Compliant with semVer major & patch version (ie included BREAKING CHANGE)
• zz: Compliant with semVer patch version

It is recommended for users to pin version as below:

"devDependencies": {
  "vue2-jest": "^27.1.1", // Not recommended. It means 27.1.1 <= x < 28.0.0
  "vue2-jest": "27.1.x", // 27.1.0 <= x < 27.2.0
  "vue2-jest": "~27.1", // 27.1.0 <= x < 27.2.0
  "vue2-jest": "~27.1.1" // 27.1.1 <= x < 27.2.0
}

Repository Structures

• .github/
• e2e/
  • 2.x/
  • 3.x/
• packages/
  • vue2-jest/
    • src/
    • test/
    • package.json
    • README.md
  • vue3-jest/
    • src/
    • test/
    • package.json
    • README.md
  • core/
    • src/
    • test/
    • package.json
• .editorconfig
• .eslintrc
• .prettierignore
• LICENSE
• package.json
• README.md
• yarn.lock

Tasks

1. Add missing dependencies in /e2e projects
   • master branch (fix(deps): add missing devDependencies in e2e/ projects (for 4.x) #356)
   • next branch (chore(deps): bump postcss from 7.0.27 to 7.0.36 #357)
2. Setup monorepo in master branch (build: migrate to monorepo (for vue-jest@4) #360)
   • move vue-jest@4 library to /packages/vue2-jest
   • rename package to vue2-jest
   • move end-to-end tests to /e2e/2.x
3. Setup monorepo in next branch (build: migrate to monorepo (for vue-jest@5) #361)
   • move vue-jest@5 library to /packages/vue3-jest
   • rename package to vue3-jest
   • move end-to-end tests to /e2e/3.x
4. Merge next branch into master (build: merge 'next' (Vue 3) branch into 'master' (Vue 2) for monorepo #363)
5. (Optional) Split duplicated code in another package (like /packages/vue-jest-core)
6. Create vue-jest package that wraps vue2-jest@latest
7. Add or update README
   • vue-jest
   • vue2-jest
   • vue3-jest
   • root
8. Release vue2-jest, vue3-jest, and vue-jest-core

Consideration (Resolved)

Package name

• vue2-jest, vue-jest
• vue2-jest, vue3-jest
• vue2-jest, vue3-jest, vue-jest(alias of vue3-jest)
• Other

Use semver or not

• Yes, we will release new packages as version 1.x. Major version does not match Jest version.
• No, like ts-jest, we will release new packages as version 27.x. Major version matches Jest version.

Deprecates vue-jest or not

• **Yes.
• No. use vue-jest as alias of latest Vue + Jest package (currently vue3-jest@latest)

[nogic1008]

Ultimately, it will have the same structure as the branch in this repository..

[lmiller1990]

Thanks for putting together this document. It's really good. Here's my thoughts:

Consideration

Package name

• vue2-jest, vue-jest
• vue2-jest, vue3-jest
• vue2-jest, vue3-jest, vue-jest(alias of vue3-jest)
• Other

I think this makes sense. Evan agrees, too. We will just need to ensure that vue-jest always matches the latest version of the current release (so right now it'll be vue2-jest). Once Vue 3 becomes the main version on npm for Vue, we will change it.

I'm not sure if npm has the concept of an alias, but I think there should be some way to set this up.

Use semver or not

• Yes, we will release new packages as version 1.x. Major version does not match Jest version.
• No, like ts-jest, we will release new packages as version 27.x. Major version matches Jest version.

I think it makes sense to match the Jest version. Currently we have vue-jest v3, v4 and v5 - it's not at all clear which version of Vue they work with. It makes more sense to match the Jest version.

Deprecates vue-jest or not

• Yes.
• No. use vue-jest as alias of latest Vue + Jest package (currently vue3-jest@latest)

Agree, but currently this should match vue2-jest, also known as vue-jest@4. We should match the main version of Vue on npm. At the moment, that's Vue 2.

Structure

Happy to let you own this, and decide whatever you think is best.

Final Thoughts

As a final recommendation, when you move or copy and files, please do git mv. This will preserve the git history.

If you'd like to work on this, I can review any code or PRs you've made. I think it's fine to fork this repository. Again, please use git mv if you are moving things around so we can keep the history.

[nogic1008]

@lmiller1990
Thank you for your thoughts!
I wrote "Details" section. If you find any mistakes or have any questions, please let me know.

I'll send PRs for monorepo, but please do not "Squash Merge".
It can sometimes break git mv history.

[lmiller1990]

Sounds good, I'll look forward to the PR.

I'll make sure not to squash merge that PR.