papers/lux-distributed-systems-testing/sections/05-layer-4-end-to-end-tests.tex

\section{Layer 4: End-to-End Tests}


E2E tests run the full system (multiple node processes, real networking, real storage)
and verify user-visible behavior.

\subsection{Playwright for Web/API E2E}

\begin{lstlisting}[language=TypeScript,caption={Playwright E2E test for transaction submission}]
import { test, expect } from '@playwright/test';

test('submit transaction and verify inclusion', async ({ request }) => {
  // Submit a transfer transaction
  const txHash = await submitTransaction(request, {
    from: testAccount1,
    to: testAccount2,
    value: '1000000000000000000', // 1 LUX
  });

  // Wait for block inclusion
  const receipt = await waitForReceipt(request, txHash, {
    timeout: 30000,
  });
  expect(receipt.status).toBe(1);
  expect(receipt.blockNumber).toBeGreaterThan(0);

  // Verify balance change
  const balance = await getBalance(request, testAccount2);
  expect(BigInt(balance)).toBeGreaterThanOrEqual(
    BigInt('1000000000000000000')
  );
});
\end{lstlisting}

\subsection{Network E2E Tests}

Our network E2E tests use the Lux CLI to spin up local networks and verify:
\begin{itemize}[nosep]
  \item Chain bootstrapping and block production.
  \item Cross-chain messaging (Teleport).
  \item Validator addition/removal during operation.
  \item Node restart and state recovery.
\end{itemize}

\begin{lstlisting}[language=bash,caption={E2E test via Lux CLI}]
# Start a local 5-node network
lux network start --nodes 5

# Wait for chain to produce blocks
lux network health --wait 30s

# Submit transactions
lux transaction send --amount 1 --to 0x1234...

# Verify finality
lux chain status --chain C

# Stop network
lux network stop
\end{lstlisting}

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