mev-beta/docs/planning/10_LOW-002_Testing_Infrastructure_Plan.md

# LOW-002: Testing Infrastructure - Detailed Fix Plan

**Issue ID:** LOW-002  
**Category:** Quality  
**Priority:** Low  
**Status:** Not Started  
**Generated:** October 9, 2025  
**Estimate:** 8-10 hours  

## Overview
This plan expands the testing infrastructure to include comprehensive fuzzing tests, property-based testing for mathematical operations, an integration security test suite, and performance regression tests for security features. The goal is to improve test coverage and catch potential issues before they reach production.

## Current Implementation Issues
- Limited fuzzing test coverage for critical components
- Lack of property-based testing for mathematical operations
- Missing integration security test suite
- No performance regression tests for security features

## Implementation Tasks

### 1. Expand Fuzzing Test Coverage for All Critical Components
**Task ID:** LOW-002.1  
**Time Estimate:** 2.5 hours  
**Dependencies:** None

Implement comprehensive fuzzing tests for critical system components:
- Identify critical functions that process untrusted input
- Create fuzzing functions using Go's new fuzzing framework
- Focus on parsing, validation, and calculation functions
- Set up fuzzing in CI pipeline with appropriate timeout values

```go
// Example fuzzing test for transaction parsing
func FuzzParseTransaction(f *testing.F) {
    // Add interesting seeds
    f.Add([]byte{}) // Empty input
    f.Add([]byte{0x01, 0x02, 0x03})
    f.Add([]byte{0xf8, 0x6c, 0x80, 0x85}) // Potential transaction header
	
    f.Fuzz(func(t *testing.T, data []byte) {
        // Test should not panic with any input
        _, err := ParseTransaction(data)
        if err != nil {
            // Log errors only if they represent new bugs, not expected validation failures
            if !isExpectedError(err) {
                t.Errorf("Unexpected error: %v", err)
            }
        }
    })
}

// Example fuzzing for ABI decoding
func FuzzABIDecode(f *testing.F) {
    f.Add([]byte{}, "uint256")
    f.Add([]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01}, "uint256")
	
    f.Fuzz(func(t *testing.T, data []byte, typeName string) {
        // Test ABI decoding with various inputs
        abiType, err := NewType(typeName, "", nil)
        if err != nil {
            return  // Skip invalid type names
        }
        
        _, err = Unpack(abiType, data)
        if err != nil {
            // Log errors only if they represent invalid behavior, not validation failures
            if !isExpectedValidationError(err) {
                t.Errorf("Unexpected error in ABI decoding: %v", err)
            }
        }
    })
}

// Helper function to determine if an error is expected
func isExpectedError(err error) bool {
    // Define which errors are expected during fuzzing
    expected := []string{
        "invalid input",
        "insufficient data",
        "validation failed",
    }
    
    errStr := err.Error()
    for _, exp := range expected {
        if strings.Contains(strings.ToLower(errStr), exp) {
            return true
        }
    }
    return false
}
```

### 2. Add Property-Based Testing for Mathematical Operations
**Task ID:** LOW-002.2  
**Time Estimate:** 2 hours  
**Dependencies:** None

Implement property-based testing for mathematical operations in the codebase:
- Test mathematical properties like commutativity, associativity
- Verify precision and accuracy of calculations
- Test edge cases and boundary conditions
- Use tools like `gopter` for property-based testing

```go
// Example property-based test for mathematical operations (using gopter-like approach)
func TestMathProperties(t *testing.T) {
    // Test property: a + b = b + a (commutativity)
    prop := proptest.ForAll(
        func(nums [2]*big.Int) bool {
            // Test with uint256 values to stay within range
            a := new(uint256.Int).SetBytes(nums[0].Bytes())
            b := new(uint256.Int).SetBytes(nums[1].Bytes())
            
            sumAB := new(uint256.Int).Add(a, b)
            sumBA := new(uint256.Int).Add(b, a)
            
            return sumAB.Eq(sumBA)
        },
        proptest.GenSlice(proptest.GenBigNat),
    )
    
    if err := prop.Testing(t); err != nil {
        t.Errorf("Commutativity property failed: %v", err)
    }
}

// Example for multiplicative identity
func TestMultiplicativeIdentity(t *testing.T) {
    prop := proptest.ForAll(
        func(num *big.Int) bool {
            a := new(uint256.Int).SetBytes(num.Bytes())
            one := uint256.NewInt(1)
            result := new(uint256.Int).Mul(a, one)
            
            return result.Eq(a)
        },
        proptest.GenBigNat,
    )
    
    if err := prop.Testing(t); err != nil {
        t.Errorf("Multiplicative identity property failed: %v", err)
    }
}

// Property test for arbitrage calculations
func TestArbitrageCalculationProperties(t *testing.T) {
    prop := proptest.ForAll(
        func(amount *big.Int, rate *big.Float) bool {
            // Test that arbitrage calculation is consistent
            // Convert to appropriate types
            inputAmount := new(uint256.Int).SetBytes(amount.Bytes())
            
            // Ensure rate is in reasonable range
            if rate.Cmp(big.NewFloat(0.000001)) < 0 || rate.Cmp(big.NewFloat(1000000)) > 0 {
                return true  // Skip unreasonable rates
            }
            
            // Perform arbitrage calculation
            output, err := CalculateArbitrageReturn(inputAmount, rate)
            if err != nil {
                return true  // Expected error for invalid inputs
            }
            
            // Property: output should be positive when input and rate are positive
            return output.Sign() >= 0
        },
        proptest.GenBigNat,
        proptest.GenBigFloat,
    )
    
    if err := prop.Testing(t); err != nil {
        t.Errorf("Arbitrage calculation property failed: %v", err)
    }
}
```

### 3. Implement Integration Security Test Suite
**Task ID:** LOW-002.3  
**Time Estimate:** 2 hours  
**Dependencies:** LOW-002.1, LOW-002.2

Create a comprehensive integration security test suite:
- Test security controls in integrated system components
- Simulate security attack scenarios
- Test authentication and authorization across components
- Verify that security measures work together properly

```go
// Example integration security test suite
func TestIntegrationSecuritySuite(t *testing.T) {
    // Setup test environment with mocked dependencies
    testEnv := setupSecureTestEnvironment(t)
    defer testEnv.Teardown()

    tests := []struct {
        name        string
        setup       func(*TestEnvironment)
        runTest     func(*testing.T, *TestEnvironment)
        expectError bool
    }{
        {
            name: "transaction_signing_with_invalid_key",
            setup: func(env *TestEnvironment) {
                env.MockKeyManager.AddInvalidKey("malicious_key_id")
            },
            runTest: func(t *testing.T, env *TestEnvironment) {
                _, err := env.TransactionSigner.SignWithKey("malicious_key_id", env.TestTransaction)
                assert.Error(t, err)
            },
            expectError: true,
        },
        {
            name: "double_sign_prevention",
            setup: func(env *TestEnvironment) {
                env.TransactionStore.Clear()
            },
            runTest: func(t *testing.T, env *TestEnvironment) {
                // First signing should succeed
                _, err1 := env.TransactionSigner.SignWithKey("test_key", env.TestTransaction)
                require.NoError(t, err1)
                
                // Second signing with same nonce should fail
                _, err2 := env.TransactionSigner.SignWithKey("test_key", env.TestTransaction)
                assert.Error(t, err2)
            },
            expectError: true,
        },
        {
            name: "rate_limiting_integration",
            setup: func(env *TestEnvironment) {
                env.RateLimiter.SetLimit("test_user", 1, time.Second)
            },
            runTest: func(t *testing.T, env *TestEnvironment) {
                // First request should succeed
                success1 := env.RateLimiter.Allow("test_user")
                assert.True(t, success1)
                
                // Second request should fail
                success2 := env.RateLimiter.Allow("test_user")
                assert.False(t, success2)
            },
            expectError: false,
        },
    }

    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            tt.setup(testEnv)
            tt.runTest(t, testEnv)
        })
    }
}

// Security scenario testing
func TestSecurityScenarios(t *testing.T) {
    testEnv := setupSecureTestEnvironment(t)
    defer testEnv.Teardown()

    scenarios := []struct {
        name        string
        description string
        execute     func() error
    }{
        {
            name:        "replay_attack_prevention",
            description: "Verify transactions cannot be replayed",
            execute: func() error {
                // Create and sign a transaction
                tx := testEnv.CreateTestTransaction()
                signedTx, err := testEnv.Signer.SignTx(tx, testEnv.TestKey)
                if err != nil {
                    return err
                }
                
                // Submit transaction twice - second should fail
                err1 := testEnv.SubmitTransaction(signedTx)
                if err1 != nil {
                    return fmt.Errorf("first transaction failed: %w", err1)
                }
                
                err2 := testEnv.SubmitTransaction(signedTx)  // Replay attempt
                if err2 == nil {
                    return fmt.Errorf("replay attack succeeded - second transaction was accepted")
                }
                
                return nil
            },
        },
        {
            name:        "malicious_contract_interaction",
            description: "Verify protection against malicious contract calls",
            execute: func() error {
                // Create transaction with potentially malicious data
                maliciousData := createMaliciousContractCall()
                
                // Attempt to process - should be rejected by validation
                err := testEnv.ProcessContractCall(maliciousData)
                if err == nil {
                    return fmt.Errorf("malicious contract call was not rejected")
                }
                
                return nil
            },
        },
    }

    for _, scenario := range scenarios {
        t.Run(scenario.name, func(t *testing.T) {
            if err := scenario.execute(); err != nil {
                t.Errorf("%s failed: %v", scenario.description, err)
            }
        })
    }
}
```

### 4. Create Performance Regression Tests for Security Features
**Task ID:** LOW-002.4  
**Time Estimate:** 1.5 hours  
**Dependencies:** LOW-002.1, LOW-002.2, LOW-002.3

Develop performance regression tests for security features:
- Benchmark security-related functions
- Track performance of validation and verification operations
- Establish performance baselines and alert on regressions
- Test performance under load for security operations

```go
// Benchmark security-critical functions
func BenchmarkTransactionValidation(b *testing.B) {
    tx := createTestTransaction()
    validator := NewTransactionValidator()
    
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        _ = validator.Validate(tx)
    }
}

func BenchmarkSignatureVerification(b *testing.B) {
    tx := createTestTransaction()
    signer, _ := NewTransactionSigner(testPrivateKey)
    signedTx, _ := signer.SignTx(tx, testPrivateKey)
    
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        valid, _ := VerifySignature(signedTx)
        if !valid {
            b.Fatal("Signature verification failed unexpectedly")
        }
    }
}

// Performance regression test with thresholds
func TestSecurityPerformanceRegression(t *testing.T) {
    // Load baseline performance data
    baselineData := loadPerformanceBaseline()
    
    tests := []struct {
        name       string
        benchmark  func() time.Duration
        threshold  time.Duration
    }{
        {
            name: "transaction_validation",
            benchmark: func() time.Duration {
                start := time.Now()
                tx := createTestTransaction()
                validator := NewTransactionValidator()
                _ = validator.Validate(tx)
                return time.Since(start)
            },
            threshold: baselineData.TransactionValidation + (10 * time.Millisecond), // 10ms tolerance
        },
        {
            name: "signature_verification",
            benchmark: func() time.Duration {
                start := time.Now()
                tx := createTestTransaction()
                signer, _ := NewTransactionSigner(testPrivateKey)
                signedTx, _ := signer.SignTx(tx, testPrivateKey)
                _ = VerifySignature(signedTx)
                return time.Since(start)
            },
            threshold: baselineData.SignatureVerification + (5 * time.Millisecond), // 5ms tolerance
        },
        {
            name: "input_validation",
            benchmark: func() time.Duration {
                start := time.Now()
                data := make([]byte, 1024)
                _ = validateInputData(data)
                return time.Since(start)
            },
            threshold: baselineData.InputValidation + (2 * time.Millisecond), // 2ms tolerance
        },
    }
    
    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            duration := tt.benchmark()
            
            if duration > tt.threshold {
                t.Errorf("%s performance regressed: took %v, threshold %v", 
                    tt.name, duration, tt.threshold)
            }
            
            // Log performance for monitoring
            t.Logf("%s took %v", tt.name, duration)
        })
    }
}

// Load test for security features
func TestSecurityUnderLoad(t *testing.T) {
    if testing.Short() {
        t.Skip("skipping load test in short mode")
    }
    
    numWorkers := 10
    numOperations := 1000
    var wg sync.WaitGroup
    
    // Start workers to perform security-sensitive operations
    for i := 0; i < numWorkers; i++ {
        wg.Add(1)
        go func(workerID int) {
            defer wg.Done()
            
            for j := 0; j < numOperations; j++ {
                // Perform some security-sensitive operation
                tx := createTestTransaction()
                validator := NewTransactionValidator()
                
                err := validator.Validate(tx)
                if err != nil {
                    t.Errorf("Worker %d, operation %d failed validation: %v", workerID, j, err)
                }
            }
        }(i)
    }
    
    wg.Wait()
    
    // Verify system performance under load
    assert.True(t, time.Since(startTime) < maxAcceptableTime,
        "Security operations took too long under load")
}
```

## Testing Infrastructure Setup

### Continuous Integration Integration
```yaml
# Example CI configuration for new tests
name: Security Testing
on: [push, pull_request]
jobs:
  fuzzing-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Setup Go
        uses: actions/setup-go@v3
        with:
          go-version: '1.21'
      - name: Run Fuzzing Tests
        run: |
          go test -fuzz=. -fuzztime=10s ./pkg/...
  
  property-based-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Setup Go
        uses: actions/setup-go@v3
        with:
          go-version: '1.21'
      - name: Run Property Tests
        run: |
          go test -tags=property ./test/property/...
  
  performance-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Setup Go
        uses: actions/setup-go@v3
        with:
          go-version: '1.21'
      - name: Run Performance Tests
        run: |
          go test -bench=. -benchmem ./pkg/security/...
```

## Testing Strategy
- Unit tests for each new testing approach
- Integration tests to verify testing infrastructure works properly
- Load testing to ensure tests don't cause system degradation
- Regular execution of expanded test suite

## Code Review Checklist
- [ ] Fuzzing tests added for critical input parsing functions
- [ ] Property-based tests implemented for mathematical operations
- [ ] Integration security test suite created and functional
- [ ] Performance regression tests established with baselines
- [ ] Tests are deterministic and reliable
- [ ] Test coverage metrics improved
- [ ] Performance impact of tests is acceptable

## Rollback Strategy
If the new testing infrastructure causes issues:
1. Temporarily disable new test types in CI
2. Revert to previous test suite while investigating
3. Address any performance issues with the new tests

## Success Metrics
- Significant increase in test coverage for security-critical code
- Zero crashes from fuzzing tests in production code paths
- Property-based tests validate mathematical invariants
- Security integration tests catch issues before deployment
- Performance regression tests prevent security feature slowdowns
- All new tests pass consistently in CI/CD pipeline