Validate Change

Validate Change

Validate proposed code changes against codebase patterns before committing. Catches pattern violations, constraint breaches, and inconsistencies early.

Overview

Before committing code, validate it matches your codebase conventions:

┌─────────────────────────────────────────────────────────────────┐
│                    VALIDATION RESULT                             │
├─────────────────────────────────────────────────────────────────┤
│                                                                  │
│  File: src/api/users.ts                                          │
│  Status: ⚠️ WARNINGS (2)                                         │
│                                                                  │
│  Compliance Score: 78/100                                        │
│                                                                  │
│  ✅ PASSED                                                       │
│  • REST Controller Pattern                                       │
│  • Error Handling Pattern                                        │
│  • Logging Pattern                                               │
│                                                                  │
│  ⚠️ WARNINGS                                                     │
│  • Response envelope missing meta.requestId                      │
│  • Missing rate limiting middleware                              │
│                                                                  │
│  💡 SUGGESTIONS                                                  │
│  • Add requestId to response meta for tracing                    │
│  • Consider adding @RateLimit decorator                          │
│                                                                  │
└─────────────────────────────────────────────────────────────────┘

---

MCP Tools

drift_validate_change

Validate complete file content:

drift_validate_change({
  file: "src/api/users.ts",
  content: `
    @Controller('/api/users')
    export class UsersController {
      @Get('/:id')
      async getUser(@Param('id') id: string) {
        const user = await this.userService.findById(id);
        return { data: user };
      }
    }
  `,
  strictMode: false
})

Or validate a diff:

drift_validate_change({
  file: "src/api/users.ts",
  diff: `
--- a/src/api/users.ts
+++ b/src/api/users.ts
@@ -10,6 +10,10 @@ export class UsersController {
+  @Post('/')
+  async createUser(@Body() dto: CreateUserDto) {
+    return this.userService.create(dto);
+  }
  `,
  strictMode: true
})

Response:

{
  "summary": "⚠️ Code has 2 warning(s) (78% compliance)",
  "data": {
    "summary": "⚠️ Code has 2 warning(s) (78% compliance)",
    "file": "src/api/users.ts",
    "overallScore": 78,
    "status": "warn",
    "violations": [
      {
        "patternId": "api-response-envelope",
        "patternName": "Response Envelope Pattern",
        "severity": "warning",
        "message": "Response envelope missing meta.requestId",
        "line": 8,
        "suggestion": "Add requestId: req.id to meta object",
        "confidence": 0.85
      },
      {
        "patternId": "semantic-sensitive-data",
        "patternName": "Sensitive Data Access",
        "severity": "info",
        "message": "Accessing sensitive fields: password_hash",
        "line": 12,
        "suggestion": "Ensure proper authorization and audit logging for sensitive data access",
        "confidence": 0.9
      }
    ],
    "compliance": [
      {
        "patternId": "api-rest-controller",
        "patternName": "REST Controller Pattern",
        "status": "compliant",
        "score": 100,
        "details": "1/1 semantic checks passed"
      },
      {
        "patternId": "error-handling-try-catch",
        "patternName": "Error Handling Pattern",
        "status": "compliant",
        "score": 100,
        "details": "1/1 semantic checks passed"
      }
    ],
    "semanticValidation": {
      "functions": {
        "total": 0,
        "withErrorHandling": 0,
        "async": 0,
        "exported": 0
      },
      "dataAccess": {
        "total": 2,
        "rawSql": 0,
        "sensitiveFields": 1
      },
      "imports": {
        "total": 0,
        "external": 0
      }
    },
    "suggestions": [
      "Review sensitive data access for proper authorization",
      "Add requestId: req.id to meta object"
    ],
    "stats": {
      "patternsChecked": 4,
      "compliant": 2,
      "violations": 0,
      "warnings": 2
    }
  },
  "hints": {
    "nextActions": [
      "Review violations and apply suggested fixes",
      "Use drift_suggest_changes for detailed fix suggestions",
      "Use drift_code_examples to see correct implementations"
    ],
    "relatedTools": ["drift_suggest_changes", "drift_code_examples", "drift_pattern_get"]
  }
}

drift_prevalidate

Quick validation before writing code (lighter weight):

drift_prevalidate({
  code: `
    async function createUser(data: CreateUserDto) {
      return await prisma.user.create({ data });
    }
  `,
  targetFile: "src/services/user.ts",
  kind: "function"
})

Kind Options:

Kind	Description
function	Single function
class	Class definition
component	React/Vue component
test	Test file
full-file	Complete file

Response:

{
  "summary": "Code looks good! Score: 85/100. Matches expected patterns.",
  "data": {
    "valid": true,
    "score": 85,
    "violations": [],
    "expectedPatterns": ["data-access-prisma", "async-await", "dto-patterns"],
    "suggestions": [
      "Wrap async operations in try/catch"
    ]
  },
  "hints": {
    "nextActions": [
      "Code is ready to write",
      "Use drift_imports to add correct imports"
    ],
    "relatedTools": ["drift_code_examples", "drift_imports", "drift_similar"]
  }
}

---

CLI Commands

Validate Staged Files

drift check --staged

Validates all staged files before commit.

Validate Specific Files

drift check src/api/users.ts src/services/user.ts

Strict Mode

drift check --staged --fail-on warning

Fails on any warning (not just errors).

---

Validation Modes

Standard Mode

drift_validate_change({
  file: "src/api/users.ts",
  content: code,
  strictMode: false  // Default
})

• Errors block merge
• Warnings are advisory
• Suggestions are informational

Strict Mode

drift_validate_change({
  file: "src/api/users.ts",
  content: code,
  strictMode: true
})

• Errors block merge
• Warnings block merge
• Used for main/release branches

---

What Gets Validated

1. Pattern Compliance

Does the code follow established patterns?

{
  "compliance": [
    { 
      "patternId": "api-rest-controller",
      "patternName": "REST Controller Pattern",
      "status": "compliant",
      "score": 100,
      "details": "1/1 semantic checks passed"
    }
  ],
  "violations": [
    { 
      "patternId": "error-handling",
      "patternName": "Error Handling Pattern",
      "severity": "warning",
      "message": "Missing try-catch",
      "suggestion": "Add try/catch or use Result<T> pattern"
    }
  ]
}

2. Semantic Validation

Analyzes data access patterns and security concerns:

{
  "semanticValidation": {
    "functions": { "total": 3, "withErrorHandling": 2, "async": 3, "exported": 2 },
    "dataAccess": { "total": 2, "rawSql": 0, "sensitiveFields": 1 },
    "imports": { "total": 5, "external": 3 }
  }
}

3. Security Checks

Are there security concerns?

{
  "violations": [
    {
      "patternId": "semantic-raw-sql",
      "patternName": "Raw SQL Detection",
      "severity": "warning",
      "message": "Raw SQL query detected accessing \"users\"",
      "line": 23,
      "suggestion": "Use parameterized queries or ORM methods to prevent SQL injection"
    }
  ]
}

---

Integration Workflows

Pre-Commit Hook

# .husky/pre-commit
drift check --staged --fail-on error

CI Pipeline

# GitHub Actions
- name: Validate Changes
  run: drift check --ci --format github

AI Agent Workflow

// 1. Generate code
const generatedCode = await generateCode(prompt);

// 2. Validate before writing
const validation = await drift_validate_change({
  file: targetFile,
  content: generatedCode
});

// 3. If issues, get suggestions
if (validation.data.status !== 'passed') {
  const suggestions = await drift_suggest_changes({
    target: targetFile,
    issue: 'pattern-violation'
  });
  
  // 4. Apply suggestions and re-validate
}

// 5. Write validated code

---

Compliance Scoring

Score Calculation

The overall score combines pattern compliance and semantic validation:

Factor	Weight
Pattern compliance	50%
Semantic validation (no raw SQL, etc.)	50%

Penalties are applied for:

• Raw SQL queries: -20 points
• Sensitive data access without protection: -10 points
• Pattern violations: varies by severity

Score Interpretation

Score	Status	Action
90-100	pass	Good to merge
70-89	warn	Review warnings
50-69	warn	Address issues
<50	fail	Significant rework needed

---

Best Practices

1. Validate Early

// Validate before writing to file
const validation = await drift_prevalidate({
  code: generatedCode,
  targetFile: "src/api/users.ts",
  kind: "function"
});

if (!validation.data.valid) {
  // Fix issues before writing
}

2. Use Appropriate Mode

// Feature branches: standard mode
drift_validate_change({ strictMode: false })

// Main branch: strict mode
drift_validate_change({ strictMode: true })

3. Address Warnings

Even if validation passes, address warnings:

if (validation.data.warnings.length > 0) {
  const suggestions = await drift_suggest_changes({
    target: file,
    issue: 'pattern-violation'
  });
}

4. Run Tests After Validation

// After validation passes
const tests = await drift_test_topology({
  action: 'affected',
  files: [file]
});

// Run affected tests

---

Next Steps

• Quality Gates — CI/CD integration
• Suggest Changes — Get fix suggestions
• Git Hooks — Pre-commit setup