feat: add isNullish function

[ilxqx]

Tip

The owner of this PR can publish a preview release by commenting /publish in this PR. Afterwards, anyone can try it out by running pnpm add radashi@pr<PR_NUMBER>.

Summary

Add isNullish function to check if the given value is null or undefined

Related issue, if any:

For any code change,

• Related documentation has been updated, if needed
• Related tests have been added or updated, if needed
• Related benchmarks have been added or updated, if needed

Does this PR introduce a breaking change?

No

Bundle impact

Status	File	Size 1
A	src/typed/isNullish.ts	53

Footnotes

1. Function size includes the import dependencies of the function. ↩

[MarlonPassos-git]

Thanks for the PR, @ilxqx. Just one thing: for functions that have type assertions, it's a good idea to include a type test to ensure that the types are working correctly. You can create the isNullish.test-d.ts file based on other test files, such as the isArray test.

[MarlonPassos-git]

@ilxqx I find some lint errors in your changes, please run the pnpm lint and fix the errors.

@aleclarson The strange part is the CI catches the error, but they do not show the error in the check result.

I'm going to try to find the CI problem

[aleclarson]

Hey @ilxqx, you should be able to run pnpm format to fix the formatting errors. Let me know if you encounter any difficulties. :)

[ilxqx]

@MarlonPassos-git I have added type test for isNullish and fixed the lint errors related to my committed file.

[ilxqx]

Hey @ilxqx, you should be able to run pnpm format to fix the formatting errors. Let me know if you encounter any difficulties. :)

I have run pnpm format and committed the changed files. It seems that everything is ok now.

[aeharding]

I would suggest that the docs mention that value == null should be considered as an alternative, with proper lint rules to help enforce this pattern :)

[aleclarson]

@aeharding That's personally what I use, but it is somewhat prone to hard-to-debug typos, since people have a muscle memory for strict equals (===).

[aleclarson]

Hey! There's a new requirement for PRs that introduce new features. Without this requirement met, we won't be able to merge this. Note that this PR can still be included in a beta prerelease before this requirement is fulfilled.

• Edit the next-minor.md file

⚠️ Note: You need to run git rebase main before this file will appear locally.

[radashi-bot]

Benchmark Results

Name	Current
isNullish: with null	4,335,020.9 ops/sec ±0.07%
isNullish: with undefined	4,180,660.34 ops/sec ±0.07%
isNullish: with number	4,541,243.64 ops/sec ±0.06%
isNullish: with string	4,211,725.05 ops/sec ±0.07%
isNullish: with array	4,518,118.83 ops/sec ±0.06%

Performance regressions of 30% or more should be investigated, unless they were anticipated. Smaller regressions may be due to normal variability, as we don't use dedicated CI infrastructure.