Added tests, and some more helpers

packages/cw0/src/macros.rs

@@ -15,20 +15,80 @@ macro_rules! ensure {
     };
 }
 
-/// Returns a generic error. In general, use ensure! with a specific ContractError variant,
-/// but some places we don't have one. This can make quick error messages in such cases.
-/// Uses .into() so that it can return StdError or any Error type with From<StdError> implemented.
+/// Opposite of ensure. If the condition (first argument) is true,
+/// then return the second argument wrapped in Err(x).
 ///
-///   ensure_generic!(id > 0, "Bad ID");
-/// is the same as
-///   if !(id > 0) {
-///     return Err(StdError::generic_err("Bad ID").into);
+///   fail_if!(!permissions.delegate, ContractError::DelegatePerm {});
+///  is the same as
+///   if !permissions.delegate {
+///     return Err(ContractError::DelegatePerm {});
 ///   }
 #[macro_export]
-macro_rules! ensure_generic {
+macro_rules! fail_if {
     ($cond:expr, $e:expr) => {
-        if !($cond) {
-            return Err(cosmwasm_std::StdError::generic_err($e).into());
+        if ($cond) {
+            return Err($e);
+        }
+    };
+}
+
+/// Quick check for a guard. Like assert_eq!, but rather than panic,
+/// it returns the second argument wrapped in Err(x).
+///
+///   ensure_eq!(info.sender, cfg.admin, ContractError::Unauthorized {});
+///  is the same as
+///   if info.sender != cfg.admin {
+///     return Err(ContractError::Unauthorized {});
+///   }
+#[macro_export]
+macro_rules! ensure_eq {
+    ($a:expr, $b:expr, $e:expr) => {
+        if $a != $b {
+            return Err($e);
         }
     };
 }
+
+#[cfg(test)]
+mod test {
+    use cosmwasm_std::StdError;
+
+    #[test]
+    fn ensure_works() {
+        let check = |a, b| {
+            ensure!(a == b, StdError::generic_err("foobar"));
+            Ok(())
+        };
+
+        let err = check(5, 6).unwrap_err();
+        assert!(matches!(err, StdError::GenericErr { .. }));
+
+        check(5, 5).unwrap();
+    }
+
+    #[test]
+    fn fail_if_works() {
+        let check = |a, b| {
+            fail_if!(a == b, StdError::generic_err("failure"));
+            Ok(())
+        };
+
+        let err = check(5, 5).unwrap_err();
+        assert!(matches!(err, StdError::GenericErr { .. }));
+
+        check(5, 6).unwrap();
+    }
+
+    #[test]
+    fn ensure_eq_works() {
+        let check = |a, b| {
+            ensure_eq!(a, b, StdError::generic_err("foobar"));
+            Ok(())
+        };
+
+        let err = check("123", "456").unwrap_err();
+        assert!(matches!(err, StdError::GenericErr { .. }));
+
+        check("123", "123").unwrap();
+    }
+}