test: get round data

Signed-off-by: Reinis Martinsons <reinis@umaproject.org>

test/mocks/MockSourceAdapter.sol

@@ -41,7 +41,7 @@ abstract contract MockSourceAdapter is DiamondRootOval {
     }
 
     function getSourceDataAtRound(uint256 roundId) public view virtual override returns (int256, uint256) {
-        if (roundId == 0 || rounds.length <= roundId) return (0, 0);
+        if (roundId == 0 || rounds.length < roundId) return (0, 0);
         RoundData memory roundData = rounds[roundId - 1];
         return (roundData.answer, roundData.timestamp);
     }

test/unit/Oval.ChainlinkDestinationAdapter.sol

@@ -77,4 +77,31 @@ contract OvalChainlinkDestinationAdapter is CommonTest {
         oval.unlockLatestValue();
         verifyOvalMatchesOval();
     }
+
+    function testReturnUninitializedRoundData() public {
+        // Advance time to within the lock window and update the source.
+        uint256 beforeLockWindow = block.timestamp + oval.lockWindow() - 1;
+        vm.warp(beforeLockWindow);
+        publishRoundData(newAnswer, beforeLockWindow);
+
+        // Before updating, uninitialized values would be returned.
+        (int256 latestAnswer, uint256 latestTimestamp) = oval.internalDataAtRound(latestPublishedRound);
+        assertTrue(latestAnswer == 0 && latestTimestamp == 0);
+    }
+
+    function testReturnUnlockedRoundData() public {
+        // Advance time to within the lock window and update the source.
+        uint256 beforeLockWindow = block.timestamp + oval.lockWindow() - 1;
+        vm.warp(beforeLockWindow);
+        publishRoundData(newAnswer, beforeLockWindow);
+
+        // Unlock new round values.
+        vm.prank(permissionedUnlocker);
+        oval.unlockLatestValue();
+        verifyOvalMatchesOval();
+
+        // After unlock we should return the new values.
+        (int256 latestAnswer, uint256 latestTimestamp) = oval.internalDataAtRound(latestPublishedRound);
+        assertTrue(latestAnswer == newAnswer && latestTimestamp == beforeLockWindow);
+    }
 }