feat: verify that vault = 0 => vaultConversionSample = 1

Author: MathisGD

src/ChainlinkOracle.sol

@@ -55,6 +55,8 @@ contract ChainlinkOracle is IOracle {
         // The vault parameter is used for ERC4626 tokens, to price its shares.
         // It is used to price `VAULT_CONVERSION_SAMPLE` of the vault shares, so it requires dividing by that number,
         // hence the division by `VAULT_CONVERSION_SAMPLE` in the `SCALE_FACTOR` definition.
+        // Verify that vault = 0 => vaultConversionSample = 1.
+        require(address(vault) != address(0) || vaultConversionSample == 1);
         VAULT = vault;
         VAULT_CONVERSION_SAMPLE = vaultConversionSample;
         BASE_FEED_1 = baseFeed1;

test/ChainlinkOracleTest.sol

@@ -131,4 +131,10 @@ contract ChainlinkOracleTest is Test {
         uint256 deviation = 0.5 ether;
         assertApproxEqRel(oracle.price(), expectedPrice, deviation);
     }
+
+    function testConstructorVaultZeroNonOneSample(uint256 vaultConversionSample) public {
+        vm.assume(vaultConversionSample != 1);
+        vm.expectRevert();
+        new ChainlinkOracle(vaultZero, daiEthFeed, feedZero, usdcEthFeed, feedZero, vaultConversionSample, 18, 6);
+    }
 }