Jest 20: mapCoverage

[Joscha Feth]

• Issue

With mapCoverage set to true, I seem to get this:

in the reports with:

when I drill into the file.

If I disable mapCoverage everything seems to work as expected regarding the coverage, but the mapping is shifted.

• Expected behavior

No file:// links

[Kulshekhar Kabra]

Can you create a minimal repo that reproduces this?

[Joscha Feth]

not yet, it seems to have something to do with:

  "modulePaths": ["<rootDir>/src"],

Before Jest 20 I was able to just have:

  "roots": ["<rootDir>/src"],

but after upgrading everything that had a relative import import x from 'bla/foo'; seemed to fail:

  ● Test suite failed to run

    Cannot find module 'base/serialization' from 'fixtures_proto.ts'

      at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:172:17)
      at Object.<anonymous> (src/base/serialization/tests/fixtures/fixtures_proto.ts:5:25)

where it worked with Jest 19, so I changed roots to modulePaths, e.g. now I have:

  "modulePaths": ["<rootDir>/src"],

adding roots additionally doesn't seem to change anything.

[Joscha Feth]

This shows the problem: https://github.com/joscha/jest-20 - I haven't found out where exactly it blows up.

[Joscha Feth]

When I remove "extends": "./tsconfig.json" it seems to generate the coverage properly, I am just not able to say why.

[Kulshekhar Kabra]

I just ran:

git clone https://github.com/joscha/jest-20
cd jest-20
yarn install
yarn test

and got these results:

yarn test v0.23.4
$ rm -rf ./target/coverage
$ jest  --config jestconfig.json --ci --coverage --no-cache 
 PASS  src/other/__tests__/index.ts
  ✓ should work (4ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        2.373s
Ran all test suites.
  console.log src/base/bla/index.ts:3
    hello


=============================== Coverage summary ===============================
Statements   : 100% ( 4/4 )
Branches     : 100% ( 0/0 )
Functions    : 100% ( 1/1 )
Lines        : 100% ( 2/2 )
================================================================================
Done in 9.24s.

[Joscha Feth]

have a look at the HTML report please in target/coverage/lcov/report.

I actually think "outDir": "target", is the problem.

[Joscha Feth]

when I remove

    "outDir": "target",

from tsconfig.json in the sample repo, then

becomes:

are we doing anything special with outDir in ts-jest?

[Kulshekhar Kabra]

We're not doing anything explicitly but it appears that having this value set is causing problems during testing.

There are two ways this can be fixed - by deleting outDir from the config during testing (hardcoded in ts-jest) or by setting its value to null in the tsconfig that testing uses (this works but gives a type warning in the editor).

I'm leaning towards the former as I don't see any need for outDir during testing. I think this can safely be hardcoded. What do you think?

[Joscha Feth]

I have set it to null for now, but I think removing it automatically would make sense. There is no output except coverage during a test run anyway, so it should be safe. Maybe add a comment to README to hint at it. Do you want me to create a PR for this?

[Kulshekhar Kabra]

Sure, that'd be great!

• add delete config.outDir; here with a comment stating why and add a link to this issue.
• change the version in package.json to 20.0.1

Thanks :)

[Joscha Feth]

PR is here: #202

[Joscha Feth]

Unfortunately, this is still not fixed due to jestjs/jest#3524

[Michał Pierzchała]

@joscha jestjs/jest#3524 (comment)

[Kulshekhar Kabra]

@thymikee does this mean we can use instrument as a proxy for collectCoverage?

[Michał Pierzchała]

Yes