[types] Add some tests for equality of pairs

types/src/pair.rs

@@ -7,7 +7,7 @@ use std::fmt;
 use super::*;
 use object::Object;
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 pub struct Pair {
     pub car: Obj,
     pub cdr: Obj
@@ -72,4 +72,11 @@ impl PartialEq<Obj> for Pair {
 #[cfg(test)]
 mod tests {
     use super::Pair;
+
+    #[test]
+    fn empty_pairs_are_equal() {
+        let a = Pair::empty();
+        let b = Pair::empty();
+        assert_eq!(a, b);
+    }
 }

types/tests/equality_value.rs

@@ -0,0 +1,16 @@
+/* types/tests/equality_value.rs
+ * Eryn Wells <eryn@erynwells.me>
+ */
+
+//! Tests of value-based equality for various types herein.
+
+extern crate sibiltypes;
+
+use sibiltypes::{Obj, Pair, Sym};
+
+#[test]
+fn pairs_with_one_similar_symbol_are_equal() {
+    let pa = Pair::with_car(Obj::new(Sym::with_str("ab")));
+    let pb = Pair::with_car(Obj::new(Sym::with_str("ab")));
+    assert_eq!(pa, pb);
+}