Strip trailing zeroes from result

Author: maltaisn

calcdialog/src/main/java/com/maltaisn/calcdialog/CalcPresenter.java

@@ -396,7 +396,8 @@ private void reset() {
 
     private void calculate() {
         try {
-            currentValue = expression.evaluate(settings.isOrderOfOperationsApplied, nbFormat.getRoundingMode());
+            currentValue = expression.evaluate(settings.isOrderOfOperationsApplied,
+                    settings.nbFormat.getMaximumFractionDigits(), nbFormat.getRoundingMode());
         } catch (ArithmeticException e) {
             // Division by zero occurred.
             setError(ERROR_DIV_ZERO);

calcdialog/src/main/java/com/maltaisn/calcdialog/Expression.java

@@ -48,7 +48,7 @@ void clear() {
      * @throws ArithmeticException if a division by zero occurred.
      */
     @NonNull
-    BigDecimal evaluate(boolean priority, RoundingMode roundingMode) {
+    BigDecimal evaluate(boolean priority, int scale, RoundingMode roundingMode) {
         if (numbers.size() != operators.size() + 1) {
             throw new IllegalStateException("Numbers and operators aren't balanced.");
         }
@@ -72,7 +72,7 @@ BigDecimal evaluate(boolean priority, RoundingMode roundingMode) {
                     ops.remove(i);
                     BigDecimal n1 = nbs.get(i);
                     BigDecimal n2 = nbs.remove(i + 1);
-                    nbs.set(i, n1.divide(n2, roundingMode));
+                    nbs.set(i, n1.divide(n2, scale, roundingMode));
                 } else {
                     i++;
                 }
@@ -91,11 +91,11 @@ BigDecimal evaluate(boolean priority, RoundingMode roundingMode) {
             } else if (op == Operator.MULTIPLY) {
                 nbs.set(0, n1.multiply(n2));
             } else {
-                nbs.set(0, n1.divide(n2, roundingMode));
+                nbs.set(0, n1.divide(n2, scale, roundingMode));
             }
         }
 
-        return nbs.remove(0);
+        return nbs.remove(0).stripTrailingZeros();
     }
 
     /**

calcdialog/src/test/java/com/maltaisn/calcdialog/ExpressionTest.java

@@ -32,8 +32,8 @@ public void twoSum() {
         expr.operators.add(Expression.Operator.ADD);
         expr.numbers.add(new BigDecimal("-24.8"));
 
-        BigDecimal result = expr.evaluate(false, RoundingMode.HALF_UP);
-        assertEquals(0, result.compareTo(new BigDecimal("-12.7")));
+        BigDecimal result = expr.evaluate(false, 8, RoundingMode.HALF_UP);
+        assertEquals(result, new BigDecimal("-12.7"));
     }
 
     @Test
@@ -45,11 +45,11 @@ public void sumAndMultiply() {
         expr.operators.add(Expression.Operator.MULTIPLY);
         expr.numbers.add(new BigDecimal("5"));
 
-        BigDecimal result1 = expr.evaluate(false, RoundingMode.HALF_UP);
-        assertEquals(0, result1.compareTo(new BigDecimal("35")));
+        BigDecimal result1 = expr.evaluate(false, 8, RoundingMode.HALF_UP);
+        assertEquals(result1, new BigDecimal("35"));
 
-        BigDecimal result2 = expr.evaluate(true, RoundingMode.HALF_UP);
-        assertEquals(0, result2.compareTo(new BigDecimal("23")));
+        BigDecimal result2 = expr.evaluate(true, 8, RoundingMode.HALF_UP);
+        assertEquals(result2, new BigDecimal("23"));
     }
 
     @Test
@@ -69,11 +69,22 @@ public void longExpression() {
         expr.operators.add(Expression.Operator.SUBTRACT);
         expr.numbers.add(new BigDecimal("-10"));
 
-        BigDecimal result1 = expr.evaluate(false, RoundingMode.HALF_UP);
-        assertEquals(0, result1.compareTo(new BigDecimal("12.41666667")));
+        BigDecimal result1 = expr.evaluate(false, 8, RoundingMode.HALF_UP);
+        assertEquals(result1, new BigDecimal("12.41666667"));
 
-        BigDecimal result2 = expr.evaluate(true, RoundingMode.HALF_UP);
-        assertEquals(0, result2.compareTo(new BigDecimal("12.33333333")));
+        BigDecimal result2 = expr.evaluate(true, 8, RoundingMode.HALF_UP);
+        assertEquals(result2, new BigDecimal("12.33333333"));
+    }
+
+    @Test
+    public void stripTrailingZeroes() {
+        Expression expr = new Expression();
+        expr.numbers.add(new BigDecimal("1"));
+        expr.operators.add(Expression.Operator.DIVIDE);
+        expr.numbers.add(new BigDecimal("8"));
+
+        BigDecimal result = expr.evaluate(false, 8, RoundingMode.HALF_UP);
+        assertEquals(result, new BigDecimal("0.125"));
     }
 
 }