Merge 6e54f647f0 into 80ec940054

decimal.go

@@ -65,6 +65,14 @@ var PowPrecisionNegativeExponent = 16
 // silently lose precision.
 var MarshalJSONWithoutQuotes = false
 
+// StringTrimTrailingZeros should be set to false if you want the decimal stringify without zeros trailing.
+// By default, when decimal is output as a string (for example, in JSON), zeros are truncated from it (2.00 -> 2, 3.11 -> 3.11, 13.000 -> 13).
+// But this logic can be changed by this variable.
+// For example, if you have numeric(10,2) values stored in your database,
+// and you want your API response to always be given 2 decimal places (even 2.00, 3.00, 17.00 [not 2,3,17]),
+// then this variable is a great way out.
+var StringTrimTrailingZeros = true
+
 // ExpMaxIterations specifies the maximum number of iterations needed to calculate
 // precise natural exponent value using ExpHullAbrham method.
 var ExpMaxIterations = 1000
@@ -130,6 +138,18 @@ func NewFromInt32(value int32) Decimal {
 	}
 }
 
+// NewFromUint64 converts an uint64 to Decimal.
+//
+// Example:
+//
+//	NewFromUint64(123).String() // output: "123"
+func NewFromUint64(value uint64) Decimal {
+	return Decimal{
+		value: new(big.Int).SetUint64(value),
+		exp:   0,
+	}
+}
+
 // NewFromBigInt returns a new Decimal from a big.Int, value * 10 ^ exp
 func NewFromBigInt(value *big.Int, exp int32) Decimal {
 	return Decimal{
@@ -1457,7 +1477,7 @@ func (d Decimal) InexactFloat64() float64 {
 //
 //	-12.345
 func (d Decimal) String() string {
-	return d.string(true)
+	return d.string(StringTrimTrailingZeros)
 }
 
 // StringFixed returns a rounded fixed-point string with places digits after

decimal_test.go

@@ -480,6 +480,7 @@ func TestNewFromInt(t *testing.T) {
 		1:                    "1",
 		323412345:            "323412345",
 		9223372036854775807:  "9223372036854775807",
+		-9223372036854775808: "-9223372036854775808",
 	}
 
 	// add negatives
@@ -505,6 +506,7 @@ func TestNewFromInt32(t *testing.T) {
 		1:           "1",
 		323412345:   "323412345",
 		2147483647:  "2147483647",
+		-2147483648: "-2147483648",
 	}
 
 	// add negatives
@@ -524,6 +526,25 @@ func TestNewFromInt32(t *testing.T) {
 	}
 }
 
+func TestNewFromUint64(t *testing.T) {
+	tests := map[uint64]string{
+		0:                    "0",
+		1:                    "1",
+		323412345:            "323412345",
+		9223372036854775807:  "9223372036854775807",
+		18446744073709551615: "18446744073709551615",
+	}
+
+	for input, s := range tests {
+		d := NewFromUint64(input)
+		if d.String() != s {
+			t.Errorf("expected %s, got %s (%s, %d)",
+				s, d.String(),
+				d.value.String(), d.exp)
+		}
+	}
+}
+
 func TestNewFromBigIntWithExponent(t *testing.T) {
 	type Inp struct {
 		val *big.Int
@@ -3673,3 +3694,48 @@ func ExampleNewFromFloat() {
 	//0.123123123123123
 	//-10000000000000
 }
+
+func TestDecimal_String(t *testing.T) {
+	type testData struct {
+		input string
+		expected string
+	}
+
+	tests := []testData{
+		{"1.22", "1.22"},
+		{"1.00", "1"},
+		{"153.192", "153.192"},
+		{"999.999", "999.999"},
+		{"0.0000000001", "0.0000000001"},
+		{"0.0000000000", "0"},
+	}
+
+	for _, test := range tests {
+		d, err := NewFromString(test.input);
+		if err != nil {
+			t.Fatal(err)
+		} else if d.String() != test.expected {
+			t.Errorf("expected %s, got %s", test.expected, d.String())
+		}
+	}
+
+	defer func() {
+		StringTrimTrailingZeros = true
+	}()
+
+	StringTrimTrailingZeros = false
+	tests = []testData{
+		{"1.00", "1.00"},
+		{"0.00", "0.00"},
+		{"129.123000", "129.123000"},
+	}
+
+	for _, test := range tests {
+		d, err := NewFromString(test.input);
+		if err != nil {
+			t.Fatal(err)
+		} else if d.String() != test.expected {
+			t.Errorf("expected %s, got %s", test.expected, d.String())
+		}
+	}
+}