package common

import (
	"math"
	"testing"

	"github.com/stretchr/testify/assert"
)

// TestQuotaFromFloat guards the billing invariant that oversized quota
// products (e.g. price multiplied by a huge user-supplied count) saturate
// instead of wrapping into a negative charge (credit).
func TestQuotaFromFloat(t *testing.T) {
	assert.Equal(t, 42, QuotaFromFloat(42.4))
	assert.Equal(t, -42, QuotaFromFloat(-42.4))
	// 2000 quota per call * n=18446744073686646784 overflows int64.
	assert.Equal(t, math.MaxInt32, QuotaFromFloat(2000*1.8446744073686647e19))
	assert.Equal(t, math.MinInt32, QuotaFromFloat(-2000*1.8446744073686647e19))
	assert.Equal(t, math.MaxInt32, QuotaFromFloat(math.Inf(1)))
	assert.Equal(t, math.MinInt32, QuotaFromFloat(math.Inf(-1)))
	assert.Equal(t, 0, QuotaFromFloat(math.NaN()))
}