[BREAKING CHANGE] remove inline source-map on process() output

[nogic1008]

Resolve #241 and jestjs/jest#10089

In jest@25.5.0 or later, coverage reporter creates an inline source-map from map property. (jestjs/jest#9811)
But vue-jest already adds inline source-map with process().
So reporter throws error due to duplicate source maps.

This PR avoids duplicates by removing map property inline source map.

[lmiller1990]

Cool, but won't this be a breaking change for anyone on an old version of jest?

We need a good strategy to handle this. I wonder if we can detect the version of jest somehow (maybe by importing package.json?)

Any ideas?

[nogic1008]

Cool, but won't this be a breaking change for anyone on an old version of jest?

We need a good strategy to handle this. I wonder if we can detect the version of jest somehow (maybe by importing package.json?)

Any ideas?

This package specifies jest@^25.x in peerDependencies.
The jest versions matching 25.x are:

• 25.5.4, 25.5.3, 25.5.2, 25.5.1, 25.5.0
• 25.4.0
• 25.3.0
• 25.2.7, 25.2.6, 25.2.4, 25.2.3, 25.2.2, 25.2.1, 25.2.0
• 25.1.0
• 25.0.0

>=25.2.3 cannot create SFC coverage due to jest's bug. (ref. #217)
So, I think we should check for breaking changes in the following versions.

• 25.4.0
• 25.3.0
• 25.2.4-25.2.7

[nogic1008]

Memo:
This issue is caused @jest/transform>=25.5.0. (dependencies of jest)
Therefore, depending on the installation timing, it may occur even jest@25.4.0 or below. (because jest@25.4.0 specifies @jest/transform:^25.4.0)

[nogic1008]

@lmiller1990
jest@25 requires @jest/transform:^25 (including @jest/transform@25.5.0) for its dependencies.
So, its bug occurs even jest@25.4.0 or below. (ex. recreate package lock file)

This version is still in beta.
I think it's better to consider this PR as a breaking change and bump jest to ^25.5.0.

[lmiller1990]

Ok let's do it. Most people should be easily able to move to Jest 25. Can you write a short "migration guide" explaining the breaking change and what people might need to do to upgrade so we can include that in the release notes?

For now I will merge this, but if you can include the upgrade notes here (just as a comment) I can include that with the release.

I will do a release in the next few days.

[nogic1008]

@lmiller1990

Ok let's do it. Most people should be easily able to move to Jest 25. Can you write a short "migration guide" explaining the breaking change and what people might need to do to upgrade so we can include that in the release notes?

For now I will merge this, but if you can include the upgrade notes here (just as a comment) I can include that with the release.

I will do a release in the next few days.

What about this one?

Breaking Change

In this version, vue-jest no longer generates inline source maps. (because jest>=25.5.0 makes it too)
Source maps are used for coverage report.
So if you want to collect coverage, upgrade jest to >=25.5.0.

# npm
> npm install jest@^25.5.0
# yarn
> yarn add jest@^25.5.0

[aantipov]

Hi there. Thanks for the fix!
Could you please also merge the changes into v4.0.0-beta? I had to turn off the coverage report before the fix arrives

Btw, I'm confused about having v4-beta and v5-alpha both at the same time.
v4-beta has been there for a while and still not achieved a stable label.

Is there any information about the future of both versions?

[lmiller1990]

This was merged into 4.0.0-beta. Maybe we need to do a release? I am not sure if we did once since this was merged. Can you check?

Basically:

v4 = Vue 2
v5 = Vue 3

I can make the next release rc.1 for v4... the release goal isn't super clear, but seems many people are using it fine in production.

[aantipov]

Maybe we need to do a release? I am not sure if we did once since this was merged. Can you check?

I see that the latest 4-beta was released on 2 Aug which happened before the fixes.
Also this page shows that the hotfix is not in the latest 4.0.0-beta.5.
So, yeah, we do need a new release of the 4-beta, or even make it rc

[matt-boyd-msm]

Is it possible to get this fix in v5 too please?

[lmiller1990]

I released a new 4.0.0 today. So it should be fixed there. This change

Is someone able to try porting this to 5.0.0? It should be quite easy. I have many other things to do in the meantime for Vue 3 release. Otherwise I can do it next week. If someone can do it sooner I can do a release just for this.

Btw, I am exploring some ideas for a ts-jest based vue-jest here: https://github.com/lmiller1990/vue-ts-jest. If that goes well maybe we can use that instead of 5.0.0 for Vue 3 (I think TS in tests is very useful; we don't get diagnostics using the babel based workflow in this codebase).