[types] Add some tests for equality of pairs

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);
+}