generating-validation-rule

What this skill does

## When to Use This Skill

Use this skill when you need to:
- Create validation rules to enforce data quality
- Prevent invalid records from being saved
- Generate validation rule metadata with formulas
- Add business logic validation to objects
- Troubleshoot deployment errors related to validation rules

## Specification

# ValidationRule Metadata Specification

### 📋 Overview
Validation Rules are declarative metadata components used to enforce data quality and business logic in Salesforce. They evaluate a formula expression when a record is saved and prevent the save operation if the expression returns TRUE.

### 🎯 Purpose
-Enforce business rules at the data layer
-Prevent invalid or incomplete records from being saved
-Display meaningful error messages to guide users

### ⚙️ Required Properties

#### Core Validation Rule Properties

- **fullName**
    - The unique API name of the validation rule
    - Must start with a letter
        - Can contain letters, numbers, and underscores
    - Cannot end with an underscore
    - Cannot contain consecutive underscores
    - Cannot exceed 40 character.

- **active**
  -Indicates whether the validation rule is enabled
  true → Rule is enforced
  false → Rule is inactive

- **errorConditionFormula**
- The logical formula that evaluates record data
- Must return TRUE or FALSE
- If TRUE, the validation rule triggers an error

- **errorMessage**
    - The message displayed to the user when validation fails
- Maximum length: 255 characters

### Specific Function Guidelines
- TEXT - TEXT() function MUST NOT be used with Text fields, to fix this you can just remove the TEXT() function.
- CASE - In salesforce CASE() function, last parameter is the default value. Admins often miss to provide this and number of parameters to CASE() function are always even.
- VALUE - VALUE() function should only be used with Text fields. If a number is being used as a parameter to the VALUE() function, remove the VALUE() function.
- DAY - DAY() function should only be used with Date fields. If a Datetime field is being used as a parameter to the DAY() function, convert it into a Date first.
- MONTH - MONTH() function should only be used with Date fields. If a Datetime field is being used as a parameter to the MONTH() function, convert it into a Date first.
- DATEVALUE - DATEVALUE() function should only be used with DateTime fields. If a Date is being used as a parameter to the DATEVALUE() function, remove the DATEVALUE() function.
- ISPICKVAL - If checking equality of a picklist type field, the function ISPICKVAL() MUST be used.
- ISCHANGE - Use ISCHANGE() function to check the value of a record has changed.

### Critical Rules
1. Formula XML Handling(MOST COMMON ERROR)
    - ANY errorConditionFormula containing XML tags MUST be inside a CDATA section in the metadata XML.

2. Interpretation of "Update" Instructions. When receiving instructions to modify a formula, distinguish between a replacement and an addition:
    - "Update the formula to [Action]": Completely replace the existing formula logic with the new requirement.
    - "Update the formula to also [Action]": Keep the existing logic and append the new requirement (usually by wrapping the logic in an AND() or OR() function).

3. File Format Requirement
    - Validation rule files MUST always use the `.validationRule-meta.xml` extension.