Merge pull request #649 from goby-lang/fix#647

Add Integer#to_d

vm/integer.go

@@ -383,6 +383,24 @@ func builtinIntegerInstanceMethods() []*BuiltinMethodObject {
 				}
 			},
 		},
+		// Returns the `Decimal` conversion of self.
+		//
+		// ```Ruby
+		// 100.to_d # => '100'.to_d
+		// ```
+		// @return [Decimal]
+		{
+			Name: "to_d",
+			Fn: func(receiver Object, sourceLine int) builtinMethodBody {
+				return func(t *thread, args []Object, blockFrame *normalCallFrame) Object {
+					if len(args) > 0 {
+						return t.vm.initErrorObject(errors.ArgumentError, sourceLine, "Expect 0 arguments. got: %d", len(args))
+					}
+					r := receiver.(*IntegerObject)
+					return t.vm.initDecimalObject(intToDecimal(r))
+				}
+			},
+		},
 		// Returns the `Float` conversion of self.
 		//
 		// ```Ruby

vm/integer_test.go

@@ -223,8 +223,17 @@ func TestIntegerConversion(t *testing.T) {
 		expected interface{}
 	}{
 		{`100.to_i`, 100},
+		{`-100.to_i`, -100},
 		{`100.to_f`, 100.0},
+		{`-100.to_f`, -100.0},
 		{`100.to_s`, "100"},
+		{`100.to_d.to_i`, 100},
+		{`-100.to_d.to_i`, -100},
+		{`100.to_d.numerator.to_i`, 100},
+		{`100.to_d.denominator.to_i`, 1},
+		{`-100.to_d.numerator.to_i`, -100},
+		{`-100.to_d.denominator.to_i`, 1},
+		{`100.to_d.class.name`, "Decimal"},
 	}
 
 	for i, tt := range tests {
@@ -236,6 +245,20 @@ func TestIntegerConversion(t *testing.T) {
 	}
 }
 
+func TestIntegerConversonFail(t *testing.T) {
+	testsFail := []errorTestCase{
+		{`100.to_d 1`, "ArgumentError: Expect 0 arguments. got: 1", 1},
+	}
+
+	for i, tt := range testsFail {
+		v := initTestVM()
+		evaluated := v.testEval(t, tt.input, getFilename())
+		checkErrorMsg(t, i, evaluated, tt.expected)
+		v.checkCFP(t, i, tt.expectedCFP)
+		v.checkSP(t, i, 1)
+	}
+}
+
 // Method test
 
 func TestIntegerEvenMethod(t *testing.T) {