MIXIN-0 [mixinnet] fix number floor.

mixinnet/number.go

@@ -37,7 +37,7 @@ func IntegerFromDecimal(d decimal.Decimal) (v Integer) {
 	if d.Sign() <= 0 {
 		panic(d)
 	}
-	s := d.Mul(decimal.New(1, Precision)).StringFixed(0)
+	s := d.Mul(decimal.New(1, Precision)).Floor().String()
 	v.i.SetString(s, 10)
 	return
 }
@@ -50,7 +50,7 @@ func IntegerFromString(x string) (v Integer) {
 	if d.Sign() <= 0 {
 		panic(x)
 	}
-	s := d.Mul(decimal.New(1, Precision)).StringFixed(0)
+	s := d.Mul(decimal.New(1, Precision)).Floor().String()
 	v.i.SetString(s, 10)
 	return
 }

mixinnet/number_test.go

@@ -0,0 +1,75 @@
+package mixinnet
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestInteger(t *testing.T) {
+	require := require.New(t)
+	require.Equal("0.00000000", NewInteger(0).String())
+
+	a := NewInteger(10000)
+	b := IntegerFromString("10000")
+	require.Equal(0, a.Cmp(b))
+
+	c := a.Add(b)
+	require.Equal("20000.00000000", c.String())
+	j, err := c.MarshalJSON()
+	require.Nil(err)
+	require.Equal("\"20000.00000000\"", string(j))
+	err = c.UnmarshalJSON(j)
+	require.Nil(err)
+	require.Equal("20000.00000000", c.String())
+
+	require.Equal(0, b.Add(a).Cmp(c))
+	require.Equal(0, c.Sub(a).Cmp(b))
+	require.Equal(0, c.Sub(b).Cmp(a))
+
+	a = IntegerFromString("0.000000001")
+	require.Equal("0.00000000", a.String())
+	a = IntegerFromString("10.000000001")
+	require.Equal("10.00000000", a.String())
+	a = IntegerFromString("0.00000001")
+	require.Equal("0.00000001", a.String())
+	a = IntegerFromString("10.00000001")
+	require.Equal("10.00000001", a.String())
+	a = IntegerFromString("0.1")
+	require.Equal("0.10000000", a.String())
+
+	m := NewInteger(500000)
+	n := m.Div(10)
+	require.Equal("50000.00000000", n.String())
+	n = m.Div(1000000)
+	require.Equal("0.50000000", n.String())
+	n = n.Div(10000000)
+	require.Equal("0.00000005", n.String())
+	require.Equal(1, n.Sign())
+	n = n.Mul(10).Div(10)
+	require.Equal("0.00000005", n.String())
+	require.Equal(1, n.Sign())
+	n = n.Div(10).Mul(10)
+	require.Equal("0.00000000", n.String())
+	require.Equal(0, n.Sign())
+
+	m = NewInteger(1)
+	n = m.Div(3)
+	require.Equal("0.33333333", n.String())
+	n = n.Mul(3)
+	require.Equal("0.99999999", n.String())
+	n = n.Add(IntegerFromString("0.00000001"))
+	require.Equal("1.00000000", n.String())
+
+	m = NewInteger(8273)
+	require.Equal("8273.00000000", m.String())
+
+	m = IntegerFromString("0.00000192")
+	require.Equal("0.00000192", m.String())
+
+	i0 := IntegerFromString("0.003790547948714634")
+	require.Equal("0.00379054", i0.String())
+	i1 := IntegerFromString(i0.String())
+	require.Equal("0.00379054", i1.String())
+	require.Equal(i0, i1)
+}