Benchmark: Is it worth checking for empty string before replace with regex?

Script Preparation code:

const arr = []
for(let i = 1; i < 1000; i++) {
    arr.push(' '.repeat(i))
}
for(let i = 1; i < 100; i++) {
    arr.push('');
    arr.push(' text '.repeat(i))
}

const run = (fn) => {
    const result = []
    for(const val of arr) {
        result.push(fn(val));
    }
    return result
}

Tests:

trim and always replace
run((val) => val.trim().replace(/\s+/g, ' '))
trim and conditionally replace
run((val) => { const trimmed = val.trim(); return trimmed && trimmed.replace(/\s+/g, ' '); })
trim and conditionally replace with if
run((val) => { const trimmed = val.trim(); if (trimmed === '') { return ''; } else { return trimmed.replace(/\s+/g, ' '); } })
always replace and trim
run((val) => val.replace(/\s+/g, ' ').trim())
conditionally trim and conditionally replace
run((val) => { if(val === '') { return val; } const trimmed = val.trim(); if (trimmed === '') { return trimmed; } else { return trimmed.replace(/\s+/g, ' '); } })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
trim and always replace
trim and conditionally replace
trim and conditionally replace with if
always replace and trim
conditionally trim and conditionally replace

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:136.0) Gecko/20100101 Firefox/136.0

Browser/OS: Firefox 136 on Mac OS X 10.15

View result in a separate tab

conditionally trim and conditionally replace

3K/s

trim and conditionally replace with if

3K/s

trim and conditionally replace

3K/s

trim and always replace

2K/s

always replace and trim

2K/s

View exact numbers

Test name	Executions per second
✓ conditionally trim and conditionally replace	2,641 Ops/sec
trim and conditionally replace with if	2,608 Ops/sec
trim and conditionally replace	2,605 Ops/sec
trim and always replace	2,454 Ops/sec
always replace and trim	2,256 Ops/sec

Is it worth checking for empty string before replace with regex? (version: 1)

Comparing performance of: `trim and always replace vs trim and conditionally replace vs trim and conditionally replace with if vs always replace and trim vs conditionally trim and conditionally replace`

Created: one year ago by: Registered User

Go to the latest result

trim and always replace

trim and conditionally replace

trim and conditionally replace with if

always replace and trim

conditionally trim and conditionally replace

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Is it worth checking for empty string before replace with regex? (version: 1)

Comparing performance of: trim and always replace vs trim and conditionally replace vs trim and conditionally replace with if vs always replace and trim vs conditionally trim and conditionally replace

Created: one year ago by: Registered User

Go to the latest result

trim and always replace

trim and conditionally replace

trim and conditionally replace with if

always replace and trim

conditionally trim and conditionally replace

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `trim and always replace vs trim and conditionally replace vs trim and conditionally replace with if vs always replace and trim vs conditionally trim and conditionally replace`