fix: Prevent assertion skip on 0 expected value

Expecting 0 value would make the conditional fail with a falsey value.
Adding additional else case to ensure the return value is undefined as
an extra check in case the assertions are not being run.

This correctly validates msg.value does indeed have the value passed to
callcode(), just not the same one as msg.value of the parent caller.

tests/e2e-evm/test/callcode.test.ts

@@ -152,8 +152,8 @@ describe("CallCode", () => {
         }),
         // msg.sender is the caller contract
         wantSender: (ctx) => ctx.lowLevelCaller.address,
-        // msg.value is not preserved via callcode
-        wantValue: 0n,
+        // msg.value is still 100 since the value is passed to callcode()
+        wantValue: 100n,
       },
       {
         name: "callcode with storage",
@@ -195,7 +195,7 @@ describe("CallCode", () => {
         const res = await publicClient.call(txData);
 
         // Check the return value for the msg.sender and msg.value if applicable
-        if (tc.wantSender && tc.wantValue) {
+        if (tc.wantSender) {
           if (!res.data) {
             // Fail this way as a type guard to ensure res.data is not undefined
             expect.fail("no data returned");
@@ -213,6 +213,8 @@ describe("CallCode", () => {
           // getAddress to ensure both are checksum encoded
           expect(getAddress(returnAddress)).to.equal(getAddress(expectedSender), "unexpected msg.sender");
           expect(returnValue).to.equal(tc.wantValue, "unexpected msg.value");
+        } else {
+          expect(res.data).to.be.undefined;
         }
 
         const txHash = await walletClient.sendTransaction(txData);
@@ -235,6 +237,7 @@ describe("CallCode", () => {
           expect(storageValue).to.equal(expectedStorage, "unexpected storage value");
         }
 
+        // Verify balance with the added value
         const balance = await publicClient.getBalance({ address: txData.to });
         const expectedBalance = startingBalance + (txData.value ?? 0n);
         expect(balance).to.equal(expectedBalance, "unexpected balance");