Rescue some case for float type data

vm/float.go

@@ -2,10 +2,10 @@ package vm
 
 import (
 	"math"
-	"strconv"
 
 	"github.com/goby-lang/goby/vm/classes"
 	"github.com/goby-lang/goby/vm/errors"
+	"strconv"
 )
 
 // FloatObject represents an inexact real number using the native architecture's double-precision floating point
@@ -406,7 +406,7 @@ func (f *FloatObject) numericComparison(t *thread, rightObject Object, operation
 // toString returns the object's value as the string format, in non
 // exponential format (straight number, without exponent `E<exp>`).
 func (f *FloatObject) toString() string {
-	return strconv.FormatFloat(f.value, 'f', -1, 64)
+	return strconv.FormatFloat(f.value, 'f', -1, 64) // fmt.Sprintf("%f", f.value)
 }
 
 // toJSON just delegates to toString

vm/float_test.go

@@ -212,3 +212,20 @@ func TestFloatConversions(t *testing.T) {
 		v.checkSP(t, i, 1)
 	}
 }
+
+func TestFloatEdgeCases(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected interface{}
+	}{
+		{`(0.1 + 0.2).to_s`, "0.30000000000000004"},
+	}
+
+	for i, tt := range tests {
+		v := initTestVM()
+		evaluated := v.testEval(t, tt.input, getFilename())
+		checkExpected(t, i, evaluated, tt.expected)
+		v.checkCFP(t, i, 0)
+		v.checkSP(t, i, 1)
+	}
+}