[Bug]: Coverage calculation is off when a React.lazy line spans multiple lines

[chulinguy]

Version

27.4.3

Steps to reproduce

I have an SPA written in React v17.2.
Formatting of code in this codebase is done by Prettier v3.
Bundling of the app is done by Create-React-App v5

Throughout the app, there are various instances of lazy import:

const PageA = React.lazy(() => import('./PATH_TO_FOLDER/PageA'))
const ComponentB = React.lazy(() => import('./PATH_TO_FOLDER/ComponentB'))

Most of these lazy importing lines get ignored by Jest in the coverage report.
However, Jest will mark a line as "uncovered" in the Jest coverage report if that line is formatted to be multiple lines by Prettier:

// Shows up as uncoverage in Jest coverage report !!!
const ComponentWithLongNameOrPath = React.lazy(() =>
  import('./PATH_TO_FOLDER/ComponentWithLongNameOrPath')
) 

Expected behavior

Multi-line lazy import should be ignored in the same way single-line lazy import is.

Actual behavior

Multi-line lazy import get marked as "uncovered"

Additional context

No response

Environment

System:
    OS: macOS 13.5
    CPU: (12) x64 Apple M2 Pro
  Binaries:
    Node: 18.17.1 - ~/.nvm/versions/node/v18.17.1/bin/node
    Yarn: 1.22.19 - ~/.nvm/versions/node/v18.17.1/bin/yarn
    npm: 9.8.1 - ~/.nvm/versions/node/v18.17.1/bin/npm

[SimenB]

Does this happen with the latest version of Jest?

[chulinguy]

@SimenB I am not able to quickly update my codebase to Jest v29 (since Create-React-App is not longer maintained)

My understanding is that coverage information actually come from packages outside of Jest.
Therefore, I would guess this issue is still present in Jest v29, since the relevant dependencies have not changed that much

jest-reporters v29.7 dependencies:

• collect-v8-coverage: "^1.0.0"
• istanbul-lib-coverage: "^3.0.0"
• istanbul-lib-instrument: "^6.0.0"
• istanbul-lib-report: "^3.0.0"
• istanbul-lib-source-maps: "^4.0.0"
• istanbul-reports: "^3.1.3"

jest-reporters v27.5 has the same dependencies except for istanbul-lib-instrument, which was at v5.1. I tried to update just istanbul-lib-instrument to v6, but the coverage report still has the same bug

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