False positive with typescript:S6606 Nullish coalescing should be preferred

Clean Code Report False-positive / False-negative...
1
  • What language is this for?
    • Typescript
  • Which rule?
    • typescript:S6606 - Nullish coalescing should be preferred
  • Why do you believe it’s a false-positive/false-negative?
    • Because || and ?? are not interchangeable in this scenario
  • Are you using
    • SonarCloud?
      • No
    • SonarQube - which version?
      • No
    • SonarLint - which IDE/version?
      • IntelliJ, plugin version 10.11.1.79663
      • in connected mode with SonarQube or SonarCloud?
        • No
  • How can we reproduce the problem? Give us a self-contained snippet of code (formatted text, no screenshots)

Take this code as an example:

const result = getSomeString()?.trim() || 'default value';

In this case, result will have 'default value' whenever getSomeString()?.trim() returns null, undefined or ''.

If I use ?? here, it will only use the default value if it returns null or undefined.

Edit: a minimal test case:

const test = '' || 'test'; // test will have 'test'
const anotherTest = '' ?? 'another test'; // anotherTest will have ''
4

Hello Guilherme,

Thank you for the feedback. I have opened a Jira issue to track the problem: [JS-373] - Jira

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