Prettier

When to Use

Use this skill when:

• After creating or modifying ANY TypeScript file
• After generating code with Aurora CLI
• Before creating a git commit
• When fixing code style inconsistencies
• After implementing handlers, services, guards, interceptors
• After writing tests

CRITICAL: Format code IMMEDIATELY after editing, not at the end of session

Critical Patterns

⚠️ MANDATORY: Format After Every Edit

Rule: Format IMMEDIATELY after modifying each file

# After editing/creating a single file
npm run format -- path/to/file.ts

# After modifying multiple files
npm run format -- path/to/file1.ts path/to/file2.ts

# Format entire directory
npm run format -- src/@app/tesla/model/**/*.ts

Workflow:

1. ✅ Read/edit file
2. ✅ IMMEDIATELY run prettier on that file
3. ✅ Verify no formatting errors
4. ✅ Move to next file

❌ NEVER:

• Skip formatting
• Format "later" or "at the end"
• Leave unformatted code
• Ignore prettier errors

Commands

Format Single File

npm run format -- <file-path>

# Example
npm run format -- src/@app/tesla/model/application/create/tesla-create-model.handler.ts

Format Multiple Files

npm run format -- <file1> <file2> <file3>

# Example
npm run format -- src/@app/tesla/model/application/create/*.ts

Format Specific Directory

npm run format -- <directory>/**/*.ts

# Example - Format all TypeScript files in module
npm run format -- src/@app/tesla/model/**/*.ts

Check Formatting (Without Writing)

npm run format:check -- <file-path>

# Useful for CI/CD or verification
npm run format:check -- src/@app/tesla/model/**/*.ts

Usage Patterns

Pattern 1: After Editing Handler

// 1. Edit the file
/* #region AI-generated code */
async execute(command: CreateTeslaModelCommand): Promise<void> {
    if (command.payload.price <= 0) {
        throw new InvalidPriceException();
    }
    await this.service.main(command.payload, command.cQMetadata);
}
/* #endregion */

// 2. IMMEDIATELY format
npm run format -- src/@app/tesla/model/application/create/tesla-create-model.handler.ts

Pattern 2: After Creating New File

# 1. Create exception file
# 2. Write content
# 3. IMMEDIATELY format
npm run format -- src/@app/tesla/model/domain/exceptions/tesla-invalid-price.exception.ts

Pattern 3: After Aurora CLI Regeneration

# 1. Regenerate module
aurora load back module -n=tesla/model -t

# 2. Format ALL generated files
npm run format -- src/@app/tesla/model/**/*.ts
npm run format -- src/@api/tesla/model/**/*.ts

Pattern 4: Before Git Commit

# 1. Check which files were modified
git status

# 2. Format all modified files
npm run format -- src/@app/tesla/model/application/create/tesla-create-model.handler.ts \
                  src/@app/tesla/model/domain/exceptions/tesla-invalid-price.exception.ts

# 3. Verify formatting succeeded
# 4. Create commit
git add .
git commit -m "feat(tesla/model): add price validation"

Integration with Other Skills

From aurora-development

After implementing business logic:

1. Edit handler/service/guard
2. Use **prettier** skill to format immediately
3. Continue to next file

From aurora-cli

After regenerating code:

1. Run aurora load command
2. Use **prettier** skill to format all generated files
3. Verify no errors

From jest-nestjs

After writing tests:

1. Write test file
2. Use **prettier** skill to format test file
3. Run tests

From conventional-commits

Before creating commit:

1. Format all modified files with **prettier** skill
2. Verify git diff shows only logical changes (not formatting)
3. Create conventional commit

Configuration

Prettier configuration is in project root:

# Configuration file (check this for project rules)
.prettierrc

# Ignore patterns
.prettierignore

Common Aurora/NestJS Configuration:

{
  "singleQuote": true,
  "trailingComma": "all",
  "tabWidth": 4,
  "semi": true,
  "printWidth": 120,
  "arrowParens": "avoid"
}

DO NOT modify prettier config without team approval.

Troubleshooting

Error: "No files matching pattern"

# Check file path is correct
ls -la src/@app/tesla/model/application/create/

# Use absolute path if needed
npm run format -- $(pwd)/src/@app/tesla/model/application/create/tesla-create-model.handler.ts

Error: "Parsing error"

# File has syntax errors - fix them first
# Check for:
# - Missing closing braces
# - Missing semicolons
# - Incomplete statements

Pre-commit Hook Fails

# Format all staged files
npm run format -- $(git diff --cached --name-only --diff-filter=ACM | grep '\.ts$')

# Or format all modified files
npm run format -- $(git diff --name-only --diff-filter=ACM | grep '\.ts$')

Quick Reference

Best Practices

✅ DO

• Format immediately after editing
• Format one file at a time during development
• Verify formatting succeeded (no errors)
• Check git diff after formatting (should show only logical changes)
• Include formatted files in commits
• Run format:check in CI/CD

❌ DON'T

• Wait until end of session to format
• Skip formatting "unimportant" files
• Ignore prettier errors
• Modify .prettierrc without approval
• Commit unformatted code
• Disable prettier in IDE

Editor Integration (Optional but Recommended)

VS Code

// .vscode/settings.json
{
  "editor.formatOnSave": true,
  "editor.defaultFormatter": "esbenp.prettier-vscode",
  "[typescript]": {
    "editor.defaultFormatter": "esbenp.prettier-vscode"
  }
}

Benefits:

• ✅ Automatic formatting on save
• ✅ Less manual npm commands
• ✅ Consistent style while coding
• ✅ Faster workflow

Still run npm run format to be sure!

Remember

• 🚨 Format IMMEDIATELY after editing each file
• 🚨 Never skip formatting
• 🚨 Verify formatting succeeded
• ✅ Formatting is part of the coding process, not an afterthought
• ✅ Consistent formatting = fewer merge conflicts
• ✅ Pre-commit hooks will enforce formatting

Integration:

• Other skills reference this skill for formatting
• This skill is invoked AFTER file modifications
• This skill is invoked BEFORE git commits