feat: add isUndefined function
#305
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| * ``` | ||
| */ | ||
| export function isUndefined(value: unknown): value is undefined { | ||
| return typeof value === 'undefined' |
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Count me surprised that this is substantially faster than === undefined (at least on Safari 16 and Chrome 132).
https://www.measurethat.net/benchmarks/Show/15532/0/undefined-vs-typeof-vs
tests/typed/isUndefined.test.ts
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| expect(result).toBeFalsy() | ||
| }) | ||
| test('returns false for string class', () => { | ||
| const result = _.isUndefined(String('abc')) |
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This is not testing what you want.
String(x) returns a string, while new String(x) returns a boxed string.
But I don't think this is a necessary test.
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These checks https://github.com/radashi-org/radashi/actions/runs/11803639848/job/32882043385?pr=305 fail with |
Benchmark Results
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. |
aleclarson
changed the title
typed/isUndefined() addedisUndefined function
aleclarson
added
new feature
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Thanks for the contribution! |
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Thanks for radashi 🎉 ! |
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A stable release To install: pnpm add [email protected]
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Tip
The owner of this PR can publish a preview release by commenting
/publishin this PR. Afterwards, anyone can try it out by runningpnpm add radashi@pr<PR_NUMBER>.Summary
The PR adds the
isUndefined()function to easily check if the passed in value isundefined.Related issue, if any:
https://github.com/orgs/radashi-org/discussions/303
For any code change,
Does this PR introduce a breaking change?
No
Bundle impact
src/typed/isUndefined.tsFootnotes
Function size includes the
importdependencies of the function. ↩