Write tests for eval.

1 files changed, 89 insertions, 1 deletions

diff --git a/src/eval.rs b/src/eval.rs
index b08bf81..dce9d68 100644
--- a/src/eval.rs
+++ b/src/eval.rs
@@ -1,6 +1,6 @@
 use std::fmt::{Display, Formatter};
 
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum Num {
     Int(i128),
     Float(f64),
@@ -211,3 +211,91 @@ impl Display for Num {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn pow_positive_int() {
+        assert_eq!(int(2).pow(int(16)), int(65536));
+    }
+
+    #[test]
+    fn pow_negative_int() {
+        assert_eq!(int(2).pow(int(-3)), float(0.125));
+    }
+
+    #[test]
+    fn pow_float() {
+        assert_eq!(int(4).pow(float(0.5)), float(2.));
+    }
+
+    #[test]
+    fn pow_overflow() {
+        assert_eq!(int(2).pow(int(1 << 126)), float(f64::INFINITY));
+    }
+
+    #[test]
+    fn pow_underflow() {
+        assert_eq!(int(2).pow(int(-(1 << 126))), float(0.));
+    }
+
+    #[test]
+    fn modulo_pos() {
+        assert_eq!(int(5).modulo(int(3)), int(2));
+    }
+
+    #[test]
+    fn modulo_pos_neg() {
+        assert_eq!(int(5).modulo(int(-3)), int(-1));
+    }
+
+    #[test]
+    fn modulo_neg_pos() {
+        assert_eq!(int(-5).modulo(int(3)), int(1));
+    }
+
+    #[test]
+    fn modulo_neg() {
+        assert_eq!(int(-5).modulo(int(-3)), int(-2));
+    }
+
+    #[test]
+    fn modulo_float_pos() {
+        assert_eq!(float(5.).modulo(int(3)), float(2.));
+    }
+
+    #[test]
+    fn modulo_float_pos_neg() {
+        assert_eq!(float(5.).modulo(int(-3)), float(-1.));
+    }
+
+    #[test]
+    fn modulo_float_neg_pos() {
+        assert_eq!(float(-5.).modulo(int(3)), float(1.));
+    }
+
+    #[test]
+    fn modulo_float_neg() {
+        assert_eq!(float(-5.).modulo(int(-3)), float(-2.));
+    }
+
+    #[test]
+    fn sqrt() {
+        for n in 0..65536 {
+            assert_eq!(
+                int(n * n).sqrt(),
+                int(n),
+                "int({}).sqrt() is not equal to {}",
+                n * n,
+                n
+            );
+        }
+    }
+
+    #[test]
+    fn sqrt_big() {
+        assert_eq!(int(1 << 126).sqrt(), int(1 << 63));
+    }
+}