Add Asset Hub Operations Example

[developerfred]

User description

This PR adds a comprehensive Asset Hub operations example to the PAPI Simulator.

Changes

• Created AssetHubExample.ts with Asset Hub specific operations
• Demonstrates foreign asset queries and balances
• Shows asset transfers, teleport assets, and reserve transfers
• Includes asset metadata and approval queries
• Advanced level example covering assets, XCM, transfers, and parachains

Features Demonstrated

• Foreign Assets: Query and interact with foreign assets on Asset Hub
• XCM Operations: Teleport assets and reserve transfers between chains
• Asset Metadata: Query asset information and approvals
• Cross-chain Transfers: Operations that work across parachains

This example helps developers understand how to work with Polkadot's Asset Hub for cross-chain asset operations.

Closes #50

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PR Type

Enhancement, Tests

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Description

• Add Asset Hub Operations example demonstrating foreign assets and XCM operations

• Implement comprehensive error handling with retry logic in code runner

• Add timeout management and error categorization for execution failures

• Register new example in the example registry

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Diagram Walkthrough

flowchart LR
  A["AssetHubExample.ts"] -->|"demonstrates"| B["Asset Hub Operations"]
  B -->|"includes"| C["Foreign Assets"]
  B -->|"includes"| D["XCM Transfers"]
  B -->|"includes"| E["Asset Metadata"]
  F["useCodeRunner.ts"] -->|"adds"| G["Error Handling"]
  G -->|"includes"| H["Retry Logic"]
  G -->|"includes"| I["Timeout Management"]
  G -->|"includes"| J["Error Categorization"]
  K["index.ts"] -->|"registers"| A

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File Walkthrough

	Relevant files
Enhancement	AssetHubExample.ts Asset Hub operations example with XCM demonstrations          src/lib/examples/AssetHubExample.ts Created new example class extending ExampleFactory for Asset Hub operations Demonstrates foreign asset queries, balances, and transfers Shows XCM operations including teleport assets and reserve transfers Includes asset metadata and approval queries with error handling Marked as advanced level with categories for assets, xcm, transfers, and parachains +168/-0
Configuration changes	index.ts Register Asset Hub example in registry                                      src/lib/examples/index.ts Import new AssetHubExample class Register AssetHubExample instance in the example registry +4/-0
Error handling	useCodeRunner.ts Implement retry logic and error categorization                      src/lib/hooks/useCodeRunner.ts Add CodeExecutionError custom error class with error type categorization (network, timeout, simulation, unknown) Implement retry logic with exponential backoff (up to maxRetries attempts) Add timeout management with configurable timeout duration (default 30 seconds) Enhance error messages with specific guidance based on error type Add progress tracking during retries and improved console output messages Extract timeout and maxRetries options from hook parameters +120/-38

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Project	Deployment	Review	Updated (UTC)
papi-simulator	Building	Preview, Comment	Dec 23, 2025 6:06pm

[qodo-code-review]

PR Compliance Guide 🔍

Below is a summary of compliance checks for this PR:

Security Compliance
🟢	No security concerns identified No security vulnerabilities detected by AI analysis. Human verification advised for critical code.
Ticket Compliance
🟡	🎫 #50 🟢 Create examples for Polkadot Asset Hub operations. Include foreign asset transfers examples. Include teleport assets (XCM) examples. Include examples interacting with Assets-related pallets on system parachains (e.g., querying assets, metadata, approvals, balances). ⚪ Confirm the example runs end-to-end against intended Asset Hub networks/descriptors (queries/tx builders match the runtime metadata for targeted chains).
Codebase Duplication Compliance
⚪	Codebase context is not defined Follow the guide to enable codebase context checks.
Custom Compliance
🟢	Generic: Comprehensive Audit Trails Objective: To create a detailed and reliable record of critical system actions for security analysis and compliance. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Meaningful Naming and Self-Documenting Code Objective: Ensure all identifiers clearly express their purpose and intent, making code self-documenting Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
🔴	Generic: Robust Error Handling and Edge Case Management Objective: Ensure comprehensive error handling that provides meaningful context and graceful degradation Status: Missing cleanup/finally: The new retry/timeout flow no longer reliably resets isRunning/progress after completion or failure and does not clear the timeout timer, risking stuck UI state and lingering timers. Referred Code async (example: Example, network: Network) => { setIsRunning(true); setProgress(10); options.onRunStart?.(); setOutputs([ { type: "log", content: `🚀 Starting execution on ${network.name}...`, timestamp: Date.now(), }, ]); let attempt = 0; let lastError: Error | null = null; while (attempt <= maxRetries) { try { setProgress(20 + (attempt * 10)); if (attempt > 0) { ... (clipped 96 lines) Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Error Handling Objective: To prevent the leakage of sensitive system information through error messages while providing sufficient detail for internal debugging. Status: Exposes raw errors: User-facing output messages embed raw lastError.message (and may include internal details) directly into UI-visible console output instead of restricting details to internal logs. Referred Code const categorizedError = new CodeExecutionError(errorMessage, errorType, lastError); // If this was the last attempt, report the error if (attempt > maxRetries) { setOutputs(prev => [...prev, { type: "error", content: `❌ ${categorizedError.message}${errorType === 'network' ? ' (Check network connection)' : ''}${errorType === 'timeout' ? ' (Try simplifying the code)' : ''}`, timestamp: Date.now(), }]); options.onRunError?.(categorizedError); } // Wait before retry (exponential backoff) if (attempt <= maxRetries) { const delay = Math.min(1000 * Math.pow(2, attempt - 1), 5000); await new Promise(resolve => setTimeout(resolve, delay)); } } } ... (clipped 6 lines) Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Logging Practices Objective: To ensure logs are useful for debugging and auditing without exposing sensitive information like PII, PHI, or cardholder data. Status: Unstructured console logs: The example emits multiple free-form console.log/console.error strings (including dumping firstAsset.value) rather than structured logs, making them difficult to parse/monitor and potentially leaking detailed internal data. Referred Code console.log("🚀 Starting Asset Hub operations demonstration..."); // 1. Query foreign assets console.log("\\n🔍 Querying foreign assets:"); const foreignAssets = await typedApi.query.ForeignAssets.Asset.getEntries(); console.log("Found", foreignAssets.length, "foreign assets"); if (foreignAssets.length > 0) { const firstAsset = foreignAssets[0]; console.log("First asset details:", { assetId: firstAsset.key?.args?.[0], details: firstAsset.value }); } // 2. Query asset balances console.log("\\n💰 Querying asset balances:"); const aliceAddress = "${this.getTestAccount("alice")}"; // Native token balance (DOT/KSM) const nativeBalance = await typedApi.query.System.Account.getValue(aliceAddress); ... (clipped 110 lines) Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Security-First Input Validation and Data Handling Objective: Ensure all data inputs are validated, sanitized, and handled securely to prevent vulnerabilities Status: Unvalidated options: timeoutMs and maxRetries are consumed without validation (e.g., negative/zero/very large values), which can cause unexpected behavior or denial-of-service style runaway execution/retry behavior. Referred Code const { timeoutMs = 30000, // 30 seconds default maxRetries = 2, } = options; Learn more about managing compliance generic rules or creating your own custom rules

Compliance status legend

🟢 - Fully Compliant
🟡 - Partial Compliant
🔴 - Not Compliant
⚪ - Requires Further Human Verification
🏷️ - Compliance label

[qodo-code-review]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
Possible issue	Restore finally block for state cleanup Restore the finally block to wrap the retry logic, ensuring the isRunning state is always reset to false after execution, which prevents the UI from getting stuck. src/lib/hooks/useCodeRunner.ts [159-171] } // If we get here, all retries failed setOutputs(prev => [...prev, { type: "error", content: `❌ All ${maxRetries + 1} attempts failed. Last error: ${lastError?.message || 'Unknown error'}`, timestamp: Date.now(), }]); options.onRunError?.(lastError || new Error('All retry attempts failed')); - }, - [options, timeoutMs, maxRetries], - ); + } finally { + setIsRunning(false); + setProgress(100); + setTimeout(() => setProgress(0), 500); + } + }, + [options, timeoutMs, maxRetries], +); [To ensure code accuracy, apply this suggestion manually] Suggestion importance[1-10]: 9 __ Why: This suggestion correctly identifies a critical bug where the isRunning state is never reset, which would freeze the UI. The proposed finally block is the correct and robust way to ensure state cleanup on both success and failure paths.	High
	Fix incorrect MultiAddress construction Correct the construction of the MultiAddress object for the target parameter by changing MultiAddress.Id(...) to { Id: "..." } to prevent a runtime error. src/lib/examples/AssetHubExample.ts [58-62] const transferTx = typedApi.tx.ForeignAssets.transfer({ id: { parents: 0, interior: { X1: { PalletInstance: 50 } } }, // Example asset ID - target: MultiAddress.Id("${this.getTestAccount("bob")}"), + target: { Id: "${this.getTestAccount("bob")}" }, amount: 1000000000000n // 1000 tokens (adjust for decimals) }); Apply / Chat Suggestion importance[1-10]: 8 __ Why: This suggestion correctly identifies a runtime error in the generated example code due to incorrect object construction for MultiAddress. Fixing this is crucial for the example to be valid and executable.	Medium
	Clear timeout to avoid leaks Clear the setTimeout timer after the Promise.race completes to prevent potential memory leaks and unhandled promise rejections if the main operation finishes before the timeout. src/lib/hooks/useCodeRunner.ts [82-95] +// Timeout promise with clearable timer +let timeoutId: ReturnType<typeof setTimeout>; const timeoutPromise = new Promise<never>((_, reject) => { - setTimeout(() => { + timeoutId = setTimeout(() => { reject(new CodeExecutionError( `Execution timed out after ${timeoutMs}ms`, 'timeout' )); }, timeoutMs); }); // Race between simulation and timeout const simulatedOutputs = await Promise.race([ simulateCodeExecution(example, network), timeoutPromise ]); +// Clear timeout to avoid unhandled rejection +clearTimeout(timeoutId); + Apply / Chat Suggestion importance[1-10]: 7 __ Why: This suggestion correctly points out a potential memory leak and unhandled promise rejection by not clearing the timeout. While this is a good practice for robustness, the current implementation's impact is minor as the timeout only logs an error.	Medium
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