diff --git a/src/formatting.rs b/src/formatting.rs
index c1853da..bb67376 100644
--- a/src/formatting.rs
+++ b/src/formatting.rs
@@ -81,49 +81,57 @@ pub fn get_significant_digits(n: &Float) -> usize {
 #[cfg(test)]
 mod tests {
     use super::*;
-    const MAX_DIGITS: usize = 10;
     fn eval(s: &str) -> Float {
         crate::nodes::eval(s).unwrap()
     }
+    macro_rules! assert_pretty_eval {
+        ($both:expr) => {
+            assert_pretty_eval!($both, $both, "should be the same as the input")
+        };
+        ($left:expr, $(|)? $( $pattern:pat_param )|+ $( if $guard: expr )? $(,)?) => {
+            std::assert_matches!(pretty_eval($left, 10).as_deref(), Ok($( $pattern )|+) $( if $guard )?)
+            // assert_pretty_eval!($left, $( $pattern )|+ $( if $guard )?, "")
+        };
+        ($left:expr, $(|)? $( $pattern:pat_param )|+ $( if $guard: expr )?, $($arg:tt)+) => {
+            std::assert_matches!(pretty_eval($left, 10).as_deref(), Ok($( $pattern )|+) $( if $guard )?, $($arg)+)
+        };
+    }
 
     #[test]
     fn character_readdition() {
-        assert_eq!(pretty_eval(" = 11", MAX_DIGITS).unwrap(), " = 11");
-        assert_eq!(pretty_eval(" &= 11", MAX_DIGITS).unwrap(), " &= 11");
-        assert_eq!(pretty_eval(" & 11", MAX_DIGITS).unwrap(), " & 11");
-        assert_eq!(pretty_eval(" & 11 \\", MAX_DIGITS).unwrap(), " & 11 \\");
+        assert_pretty_eval!(" = 11");
+        assert_pretty_eval!(" &= 11");
+        assert_pretty_eval!(" & 11");
+        assert_pretty_eval!(" & 11 \\");
     }
 
     #[test]
     fn basic_output_up_to_999() {
-        assert_eq!(pretty_eval("1", MAX_DIGITS).unwrap(), "1");
-        assert_eq!(pretty_eval("10", MAX_DIGITS).unwrap(), "10");
-        assert_eq!(pretty_eval("100", MAX_DIGITS).unwrap(), "100");
-        assert_eq!(pretty_eval("999", MAX_DIGITS).unwrap(), "999");
-        assert_eq!(pretty_eval("1000", MAX_DIGITS).unwrap(), "1 * 10^3");
+        assert_pretty_eval!("1");
+        assert_pretty_eval!("10");
+        assert_pretty_eval!("100");
+        assert_pretty_eval!("999");
+        assert_pretty_eval!("1000", "1 * 10^3");
 
-        assert_eq!(pretty_eval("11.111111", MAX_DIGITS).unwrap(), "11.111111");
+        assert_pretty_eval!("11.111111");
     }
 
     #[test]
     fn plus_minus() {
-        assert_eq!(
-            pretty_eval("y & = plus.minus sqrt(15.5) \\", MAX_DIGITS).unwrap(),
+        assert_pretty_eval!(
+            "y & = plus.minus sqrt(15.5) \\",
             "y & = plus.minus 3.937003937 \\"
         );
     }
 
     #[test]
     fn minus() {
-        assert_eq!(pretty_eval("-11", MAX_DIGITS).unwrap(), "-11");
+        assert_pretty_eval!("-11");
     }
 
     #[test]
     fn complex_prefix() {
-        assert_eq!(
-            pretty_eval("plus.minus 5 & = 5", MAX_DIGITS).unwrap(),
-            "plus.minus 5 & = 5"
-        );
+        assert_pretty_eval!("plus.minus 5 & = 5");
     }
 
     #[test]