Create React Component

This command helps you create well-structured, reusable React components for Tevm-based applications, with proper TypeScript typing and integration with Ethereum functionality.

🎯 Purpose & Scope

What this command does NOT do:

•Modify existing components
•Create non-React files
•Generate components without proper TypeScript types

When to REJECT:

•Component name is invalid or missing
•Request is to modify existing component (use edit instead)
•Request is for non-React component creation

🔄 Workflow

ultrathink: you'd perform the following steps

Step 1: Gather Requirements

•Ask user to describe the component
•Clarify component purpose and functionality
•Determine props structure and validation needs
•Identify blockchain interactions required
•Understand state management approach

Step 2: Create Component Structure

•Create component directory with proper structure
•Generate TypeScript component file with proper typing
•Implement Tevm-specific functionality
•Add JSDoc documentation

Step 3: Create Tests

•Generate test file with comprehensive coverage
•Mock Tevm client interactions
•Test component rendering and behavior
•Verify props and callbacks

Step 4: Reporting

Output Format:

code

[✅/❌] Command: create-component $ARGUMENTS

## Summary
- Component created: [name]
- Files generated: [count]
- TypeScript types: [defined]
- Tests: [created]

## Actions Taken
1. Created component file at [path]
2. Generated test file at [path]
3. Created index.ts for re-exports
4. [Created CSS module] (if needed)

## Next Steps
1. Review component implementation
2. Run tests to verify functionality
3. Import component in your application

Usage

bash

claude < .claude/create-component

Interactive Process

When you run this command, I will:

•First, ask you to describe the React component you want to create
•Rephrase your requirements in my own words to confirm understanding
•
Ask clarifying questions about:
- •Component purpose and functionality
- •Props structure and validation needs
- •Blockchain interactions required
- •State management approach
- •UI/UX considerations
- •Testing requirements
•Identify potential edge cases or performance considerations
•Create complete component files based on your feedback

Input Requirements

Before running this command, it helps to prepare:

•The name of your component
•The purpose of the component (UI element, data display, form, etc.)
•Any Tevm/blockchain functionality it needs to interact with
•Props the component should accept
•Where the component will be used

Process

I'll help you create a React component that follows best practices by:

•Analyzing your requirements to determine the appropriate component structure
•Creating properly typed component files with TypeScript
•Implementing Tevm-specific functionality (contract interactions, state reading, etc.)
•Adding proper documentation with JSDoc comments
•Creating tests for the component

Component Guide

Step 1: Define Component Structure

React components in Tevm applications typically follow this structure:

code

components/
  └── ComponentName/
      ├── ComponentName.tsx          # Main component implementation
      ├── ComponentName.test.tsx     # Component tests
      ├── ComponentName.module.css   # Styling (if needed)
      └── index.ts                   # Re-export for cleaner imports

Step 2: Create the Component

Here's a template for a typical component:

tsx

// ComponentName.tsx
import { useState, useEffect } from 'react'
import type { FC } from 'react'
import { useMemoryClient } from 'tevm/memory-client'
import styles from './ComponentName.module.css'

/**
 * Props for the ComponentName component
 */
export interface ComponentNameProps {
  /** Description of prop1 */
  prop1: string
  /** Description of prop2, which is optional */
  prop2?: number
  /** Callback function */
  onChange?: (value: string) => void
}

/**
 * ComponentName - Brief description of what this component does
 *
 * Detailed description of the component's purpose, usage context,
 * and any important behaviors or limitations.
 *
 * @example
 * ```tsx
 * <ComponentName
 *   prop1="example"
 *   prop2={42}
 *   onChange={(value) => console.log(value)}
 * />
 * ```
 */
export const ComponentName: FC<ComponentNameProps> = ({
  prop1,
  prop2 = 0, // Default value for optional prop
  onChange,
}) => {
  const [state, setState] = useState('')
  const client = useMemoryClient()

  useEffect(() => {
    // Example effect to interact with Tevm
    const fetchData = async () => {
      try {
        // Example contract interaction
        const result = await client.getBalance({
          address: prop1,
        })

        setState(result.toString())
        onChange?.(result.toString())
      } catch (error) {
        console.error('Error in ComponentName:', error)
      }
    }

    fetchData()
  }, [prop1, client, onChange])

  return (
    <div className={styles.container}>
      <h2>{prop1}</h2>
      {prop2 > 0 && <p>Value: {prop2}</p>}
      <p>Balance: {state}</p>
    </div>
  )
}

Step 3: Create the Tests

tsx

// ComponentName.test.tsx
import { render, screen, waitFor } from '@testing-library/react'
import { ComponentName } from './ComponentName'
import { MemoryClientProvider, createMemoryClient } from 'tevm/memory-client'

// Mock the Tevm client
jest.mock('tevm/memory-client', () => {
  const actual = jest.requireActual('tevm/memory-client')
  return {
    ...actual,
    useMemoryClient: () => ({
      getBalance: jest.fn().mockResolvedValue(BigInt(1000000000000000000))
    })
  }
})

describe('ComponentName', () => {
  const client = createMemoryClient()

  it('renders with required props', async () => {
    render(
      <MemoryClientProvider client={client}>
        <ComponentName prop1="0x123..." />
      </MemoryClientProvider>
    )

    expect(screen.getByText('0x123...')).toBeInTheDocument()

    await waitFor(() => {
      expect(screen.getByText('Balance: 1000000000000000000')).toBeInTheDocument()
    })
  })

  it('calls onChange when data is loaded', async () => {
    const onChange = jest.fn()

    render(
      <MemoryClientProvider client={client}>
        <ComponentName
          prop1="0x123..."
          onChange={onChange}
        />
      </MemoryClientProvider>
    )

    await waitFor(() => {
      expect(onChange).toHaveBeenCalledWith('1000000000000000000')
    })
  })
})

Step 4: Create the Index File

// index.ts
export * from './ComponentName'

Step 5: Create CSS Module (if needed)

css

/* ComponentName.module.css */
.container {
  padding: 1rem;
  border: 1px solid #eaeaea;
  border-radius: 0.5rem;
  margin-bottom: 1rem;
}

Advanced Integration Patterns

Contract Interaction Component

For components that interact with specific contracts:

tsx

import { useContract } from '../hooks/useContract'
import { MyContractAbi } from '../contracts/MyContract'

export const ContractComponent: FC<{ address: string }> = ({ address }) => {
  const contract = useContract({
    address,
    abi: MyContractAbi,
  })

  const [data, setData] = useState(null)

  useEffect(() => {
    const fetchData = async () => {
      const result = await contract.read.myMethod()
      setData(result)
    }

    fetchData()
  }, [contract])

  const handleAction = async () => {
    await contract.write.performAction()
  }

  return (
    <div>
      <p>Data: {data?.toString()}</p>
      <button onClick={handleAction}>Perform Action</button>
    </div>
  )
}

Block Data Component

For components that display block or transaction data:

tsx

import { useBlock } from '../hooks/useBlock'

export const BlockInfo: FC<{ blockNumber?: bigint }> = ({ blockNumber }) => {
  const { data, loading, error } = useBlock({ blockNumber })

  if (loading) return <p>Loading...</p>
  if (error) return <p>Error: {error.message}</p>

  return (
    <div>
      <h3>Block {data.number.toString()}</h3>
      <p>Timestamp: {new Date(Number(data.timestamp) * 1000).toLocaleString()}</p>
      <p>Gas Used: {data.gasUsed.toString()}</p>
    </div>
  )
}

Output Format

For your component, I'll provide:

•All necessary files with complete implementations
•Explanations of key design decisions
•Integration guidance for your specific use case
•Testing strategy recommendations

Examples

Example 1: Balance Display Component

A simple component that displays an account's balance:

tsx

export const BalanceDisplay: FC<{ address: string }> = ({ address }) => {
  const client = useMemoryClient()
  const [balance, setBalance] = useState<bigint>(BigInt(0))

  useEffect(() => {
    const getBalance = async () => {
      const result = await client.getBalance({ address })
      setBalance(result)
    }

    getBalance()
  }, [address, client])

  return (
    <div>
      <p>Address: {address}</p>
      <p>Balance: {formatEther(balance)} ETH</p>
    </div>
  )
}

Example 2: Transaction Form Component

A form component for submitting transactions:

tsx

export const TransactionForm: FC<{ onSubmit?: (txHash: string) => void }> = ({ onSubmit }) => {
  const client = useMemoryClient()
  const [to, setTo] = useState('')
  const [value, setValue] = useState('')
  const [sending, setSending] = useState(false)

  const handleSubmit = async (e: FormEvent) => {
    e.preventDefault()
    if (!to) return

    try {
      setSending(true)
      const txHash = await client.sendTransaction({
        to,
        value: parseEther(value || '0'),
      })

      onSubmit?.(txHash)
    } catch (error) {
      console.error('Transaction error:', error)
    } finally {
      setSending(false)
    }
  }

  return (
    <form onSubmit={handleSubmit}>
      <div>
        <label htmlFor="to">To Address:</label>
        <input
          id="to"
          value={to}
          onChange={(e) => setTo(e.target.value)}
          placeholder="0x..."
          required
        />
      </div>

      <div>
        <label htmlFor="value">Amount (ETH):</label>
        <input
          id="value"
          type="number"
          step="0.001"
          value={value}
          onChange={(e) => setValue(e.target.value)}
          placeholder="0.0"
        />
      </div>

      <button type="submit" disabled={sending}>
        {sending ? 'Sending...' : 'Send Transaction'}
      </button>
    </form>
  )
}

Evaluation Criteria

A successful component should:

•Follow React best practices (proper hooks usage, memoization when needed)
•Be fully typed with TypeScript
•Include comprehensive JSDoc comments
•Handle loading, error, and empty states
•Be properly tested
•Follow project styling conventions
•Be accessible (semantic HTML, ARIA attributes when needed)

What type of component would you like to create today?