Coverage report incorrect

I've been trying to get jest to work properly with a Vue 2 + Vite project. Jest reports pass/fail as I would expect, but the coverage report seems incorrect. Link to the repro here: https://github.com/qkjosh/vue-jest-coverage

package.json

"devDependencies": {
    "@babel/core": "7.18.5",
    "@babel/preset-env": "^7.18.2",
    "@vue/test-utils": "^1.2.2",
    "@vue/vue2-jest": "^28.0.0",
    "babel-jest": "28.1.1",
    "jest": "28.1.1",
    "jest-environment-jsdom": "28.1.1",
    "vite": "2.9.12",
    "vite-plugin-vue2": "^2.0.1"
  }

Given an incomplete test suite, the coverage report indicates 100% coverage and seems to treat the whole SFC component as one statement. Do I have something completely misconfigured, or is the coverage report broken?

[dreid]

I've also been investigating this, in our case we do not use vite, but it seems to be related to babel 7 switching from source-map to @jridgewell/gen-mapping here:

https://github.com/babel/babel/blob/main/CHANGELOG.md#v71710-2022-04-29

After some poking around I also narrowed it down to something in babel (noticed coverage working again after downgrading a few packages). Thanks for that link. Wonder if this is outside scope of vue-jest then?

[dreid]

I'm not really sure, I tried stepping through https://github.com/vuejs/vue-jest/blob/master/packages/vue2-jest/lib/generate-source-map.js and it seemed like it was not able to find the originalLine for many lines in the file.

And from investigating the jest transforms cache an indicator of this problem is that the source map for the version with incorrect coverage does not have as much mapping data as the version with correct coverage.

Its possible that vue-jest could address this by switching to https://github.com/jridgewell/trace-mapping instead of source-map or by using https://www.npmjs.com/package/@ampproject/remapping ?

[AnthonyRuelle]

same problem on my application for several weeks. It's really very blocking. Do we have a solution?

[howard-repos]

Any update?

[adelsagemilang]

I've also been investigating this, in our case we do not use vite, but it seems to be related to babel 7 switching from source-map to @jridgewell/gen-mapping here:

https://github.com/babel/babel/blob/main/CHANGELOG.md#v71710-2022-04-29

I have downgraded my @babel/core to 7.17.9 just before switched to @jridgewell/gen-mapping on 7.17.10 but it seems no luck

Anyone with a proposed solution much appreciated

[udebella]

I've also been investigating this, in our case we do not use vite, but it seems to be related to babel 7 switching from source-map to @jridgewell/gen-mapping here:
https://github.com/babel/babel/blob/main/CHANGELOG.md#v71710-2022-04-29

I have downgraded my @babel/core to 7.17.9 just before switched to @jridgewell/gen-mapping on 7.17.10 but it seems no luck

Anyone with a proposed solution much appreciated

Downgrading to 7.17.9 does not work because in @babel/core they did not freeze their dependencies. If you have a project that work, just make sure you don't upgrade @babel/core dependencies: removing and recreating your package-lock.json leads to issue. :(

My really ugly workaround is to to prevent @babel/generator to update to a buggy version. So I added inside my package.json:

  "overrides": {
    "@babel/generator": "<7.17.9"
  }

Then doing an npm install fixes broken package-lock.json.
Be careful with this fix, because it forces a version of one dependency inside @babel/core which seems to rely on consistent versions : this workaround could not work or break your project: don't forget to remove the override part from your package.json when this issue is fixed.

Maybe knowing where the issue comes from more precisely will help maintainers?

Edit: This solution works only for npm > 8.3.0 as overrides were introduced in this version. If you still use an older version, you can use @AnthonyRuelle solution
If you use yarn, you can use @BenShelton solution

[bdeo]

I'm also having this issue. Is the above PR being considered for a resolution here?

[LG0012]

Same issue

[okgo]

Same issue

[AnthonyRuelle]

Same issue ... 😩 Le mar. 26 juil. 2022 à 08:34, Yurii Rekechuk ***@***.***> a écrit :

…

Same issue — Reply to this email directly, view it on GitHub <#480 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AWJ7JAH32ITDVPH2NZILRBTVV6BFPANCNFSM5ZOORPAA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[BenShelton]

Using yarn we were able to fix this by locking both versions of @babel/core and @babel/generator to 7.17.9 (thanks to the suggestion from @udebella )

"devDependencies": {
  "@babel/core": "7.17.9"
},
"resolutions": {
  "@babel/generator": "7.17.9"
},

We only use babel for jest so this doesn't have any other side effects for us, YMMV.

[LG0012]

Any solution how to fix this? Non of the SFC file <script> block code is covered. Only works with .js mixin files.

"dependencies": {
    "babel-jest": "^28.1.3",
    "core-js": "^3.19.3",
    "jest": "^28.1.3",
    "jest-environment-jsdom": "^28.1.3",
    "nuxt": "^2.15.8",
    "vue": "^2.6.14",
    "vue-server-renderer": "^2.6.14",
    "vue-template-compiler": "^2.6.14",
    "vuetify": "^2.6.1",
    "vuex": "^3.6.2",
    "webpack": "^4.46.0"
},
"devDependencies": {
    "@babel/core": "7.18.10",
    "@babel/plugin-proposal-class-properties": "^7.14.5",
    "@babel/preset-env": "^7.15.6",
    "@babel/preset-react": "^7.14.5",
    "@nuxt/types": "~2.15.0",
    "@nuxtjs/router-extras": "^1.1.1",
    "@nuxtjs/vuetify": "^1.12.3",
    "@types/jest": "^27.0.2",
    "@vue/test-utils": "^1.2.2",
    "@vue/vue2-jest": "^28.0.1",
    "babel-core": "^7.0.0-bridge.0"
}