tests: for significant digits

src/main.rs

@@ -62,3 +62,14 @@ pub fn get_significant_digits(n: &Float) -> usize {
 
     significant_digits
 }
+
+#[test]
+fn test_get_significant_digits() {
+    let many_zeros = parse_and_calc("14.00643 + 1.00784 * 4 + 35.446 + 15.9994 * 4");
+    assert_eq!(many_zeros.to_f64(), 117.48139);
+    let many_nines = parse_and_calc("12.0096 + 15.9994 * 2");
+    assert_eq!(many_nines.to_f64(), 44.0084);
+
+    assert_eq!(get_significant_digits(&many_zeros), 8);
+    assert_eq!(get_significant_digits(&many_nines), 6);
+}