Add test suite

src/main.rs

@@ -128,3 +128,30 @@ fn main() {
     let mut prog = Program::from_string(contents);
     prog.run();
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn make_program(contents: &str) -> Program {
+        Program::from_string(contents.to_string())
+    }
+
+    #[test]
+    fn test_math() {
+        assert_eq!(eval::do_math("2-2".to_string(), '+'), 4);
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_undefined_opcode() {
+        make_program("Hello\nWorld!").run();
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_undefined_variable() {
+        make_program("p$v").run();
+    }
+
+}