v/vlib/benchmark/benchmark_test.v

import time
import benchmark

fn test_measure() {
	mut b := benchmark.start()
	time.sleep(200 * time.millisecond)
	x := b.measure('sleeping') // returns microseconds
	flush_stdout()
	assert x > 150_000
	// assert x < 800_000 // this can be much longer on a slow CI runner
}

fn test_record_measure() {
	mut b := benchmark.start()
	println('step 1')
	flush_stdout()
	time.sleep(100 * time.millisecond)
	x := b.record_measure('sleeping 1')
	assert x > 50_000
	// assert x < 200_000
	flush_stdout()

	println('step 2')
	flush_stdout()
	time.sleep(150 * time.millisecond)
	y := b.record_measure('sleeping 2')
	assert y > 100_000
	// assert y < 200_000
	flush_stdout()

	res := b.all_recorded_measures()
	println('All recorded measurements:')
	println(res)
	flush_stdout()
	assert res.contains('ms in sleeping 1')
	assert res.contains('ms in sleeping 1')
	assert res.contains('SPENT')
}

fn test_total_message() {
	mut b := benchmark.start()
	for _ in 0 .. 100 {
		time.sleep(time.millisecond)
		x := b.record_measure('sleeping 1')
		assert x > 1_000
	}

	res := b.total_message('sleeping 1')
	println(res)

	assert res.contains(' Min: ')
	assert res.contains(' Max: ')
	assert res.contains(' Avg: ')

	time.sleep(time.millisecond)
	y := b.record_measure('sleeping 2')
	assert y > 1_000
	// Should not contain min max avg, insufficient information
	res2 := b.total_message('sleeping 2')

	assert !res2.contains(' Min: ')
	assert !res2.contains(' Max: ')
	assert !res2.contains(' Avg: ')
}