Allow tests to be skipped

packages/asset-swapper/contracts/test/TestBase.sol

@@ -14,4 +14,35 @@ contract TestBase is
         arr = new uint256[](1);
         arr[0] = v;
     }
+
+    modifier requiresChainId(uint256 chainId)
+    {
+        if (chainId != _chainId())
+        {
+            emit log_string("skip: wrong chain id");
+            return;
+        }
+        _;
+    }
+
+    modifier requiresBlockNumberGte(uint256 blockNumber)
+    {
+        if (block.number < blockNumber)
+        {
+            emit log_string("skip: block.number < blockNumber");
+            return;
+        }
+        _;
+    }
+
+    function _chainId()
+        internal
+        returns (uint256 id)
+    {
+        uint256 id;
+        assembly {
+            id := chainid()
+        }
+        return id;
+    }
 }

packages/asset-swapper/contracts/test/UniswapV2Sampler.t.sol

@@ -16,13 +16,17 @@ contract UniswapV2SamplerTest is
 
     function testUniswapV2Sell()
         public
+        requiresChainId(1)
+        requiresBlockNumberGte(14000000)
     {
         address router = 0xf164fC0Ec4E93095b804a4795bBe1e041497b92a;
         address weth = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
         address usdc = 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48;
+
         address[] memory path = new address[](2);
         path[0] = weth;
         path[1] = usdc;
+
         uint256[] memory values = sampler.sampleSellsFromUniswapV2Global(
             router,
             path