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Integration Testing

The dApp template includes an IntegrationTests/ project for end-to-end testing against the full Aspire stack. Unlike the fast unit tests that use an embedded DevChain, integration tests connect to a running AppHost over HTTP — testing the real network stack, service discovery, and indexer processing.

Prerequisites​

The AppHost must be running:

dotnet run --project AppHost

Wait until all services show healthy in the Aspire dashboard before running tests.

Run the Tests​

dotnet test IntegrationTests/

By default, the tests connect to http://localhost:8545. If the DevChain is on a different port (Aspire assigns dynamic ports), set the DEVCHAIN_URL environment variable:

DEVCHAIN_URL=http://localhost:12345 dotnet test IntegrationTests/

What the Template Tests​

The template ships with three E2E tests:

1. DevChain Health Check​

Verifies the DevChain is running and responding to JSON-RPC:

var web3 = new Web3(rpcUrl);
var blockNumber = await web3.Eth.Blocks.GetBlockNumber.SendRequestAsync();
Assert.True(blockNumber.Value >= 0);

2. Deploy and Query​

Deploys MyToken to the live DevChain and verifies the contract state:

var deployment = new MyTokenDeployment
{
    Name = "E2EToken",
    Symbol = "E2E",
    InitialSupply = Web3.Convert.ToWei(1_000_000)
};

var receipt = await MyTokenService.DeployContractAndWaitForReceiptAsync(web3, deployment);
var tokenService = new MyTokenService(web3, receipt.ContractAddress);

var name = await tokenService.NameQueryAsync();
Assert.Equal("E2EToken", name);

3. Transfer with Indexing​

Deploys a token, transfers tokens, then waits for the Indexer to process the transaction. This tests the full pipeline — DevChain → Indexer → PostgreSQL:

var transferReceipt = await tokenService.TransferRequestAndWaitForReceiptAsync(
    DevChainAccounts.Account3.Address,
    Web3.Convert.ToWei(100));

// Wait for indexer to process
await Task.Delay(3000);

// Query the chain to verify
var balance = await tokenService.BalanceOfQueryAsync(DevChainAccounts.Account3.Address);
Assert.Equal(Web3.Convert.ToWei(100), balance);

The Task.Delay(3000) gives the Indexer time to pick up and process the new block. In production tests, you'd poll a health endpoint or database query instead.

Writing Your Own Integration Tests​

Integration tests are best for scenarios that span multiple services:

  • Contract deploys visible in Explorer — deploy, wait for indexing, query the Explorer's API
  • Token transfers indexed correctly — transfer tokens, verify the Indexer wrote them to PostgreSQL
  • Load generator creates expected transactions — verify transaction count increases over time
  • ABI auto-discovery works — deploy a contract from the Foundry project, verify the Explorer resolves the ABI

When to Use Integration Tests vs Unit Tests​

AspectC# Unit Tests (Tests/)Integration Tests (IntegrationTests/)
RequiresNothing (in-process)Running AppHost + Docker
SpeedSecondsMinutes (startup + processing)
TestsContract logic via typed servicesFull pipeline across services
NetworkIn-process, no HTTPReal HTTP, real ports
Use forTDD loop, fast feedbackCI pipeline, deployment verification

Use unit tests during development (fast feedback), integration tests before merging or deploying (full confidence).

Next Steps​

With both testing tiers covered, move on to building the user-facing dApp: