store/tokens.go

@@ -7,7 +7,6 @@ import (
 	"math/big"
 	"reflect"
 	"strconv"
-	"strings"
 
 	storedb "git.grassecon.net/grassrootseconomics/sarafu-vise/store/db"
 )
@@ -22,34 +21,25 @@ type TransactionData struct {
 	ActiveAddress  string
 }
 
-// TruncateDecimalString safely truncates (not rounds) a number string to the specified decimal places
+// TruncateDecimalString safely truncates the input amount to the specified decimal places
 func TruncateDecimalString(input string, decimalPlaces int) (string, error) {
-	if _, err := strconv.ParseFloat(input, 64); err != nil {
+	num, ok := new(big.Float).SetString(input)
+	if !ok {
 		return "", fmt.Errorf("invalid input")
 	}
 
-	// Split input into integer and fractional parts
-	parts := strings.SplitN(input, ".", 2)
-	intPart := parts[0]
-	var fracPart string
+	// Multiply by 10^decimalPlaces
+	scale := new(big.Float).SetInt(new(big.Int).Exp(big.NewInt(10), big.NewInt(int64(decimalPlaces)), nil))
+	scaled := new(big.Float).Mul(num, scale)
 
-	if len(parts) == 2 {
-		fracPart = parts[1]
-	}
+	// Truncate by converting to int (chops off decimals)
+	intPart, _ := scaled.Int(nil)
 
-	// Truncate or pad fractional part
-	if len(fracPart) > decimalPlaces {
-		fracPart = fracPart[:decimalPlaces]
-	} else {
-		fracPart = fracPart + strings.Repeat("0", decimalPlaces-len(fracPart))
-	}
+	// Divide back to get truncated float
+	truncated := new(big.Float).Quo(new(big.Float).SetInt(intPart), scale)
 
-	// Handle zero decimal places
-	if decimalPlaces == 0 {
-		return intPart, nil
-	}
-
-	return fmt.Sprintf("%s.%s", intPart, fracPart), nil
+	// Format with fixed decimals
+	return truncated.Text('f', decimalPlaces), nil
 }
 
 func ParseAndScaleAmount(storedAmount, activeDecimal string) (string, error) {

store/tokens_test.go

@@ -22,13 +22,6 @@ func TestTruncateDecimalString(t *testing.T) {
 			want:          "4.00",
 			expectError:   false,
 		},
-		{
-			name:          "precision test",
-			input:         "2.1",
-			decimalPlaces: 2,
-			want:          "2.10",
-			expectError:   false,
-		},
 		{
 			name:          "single decimal",
 			input:         "4.1",