| name | fluent-validation-inline-messages |
| description | Refactor FluentValidation validators to use inline WithMessage strings instead of WithErrorCode + shared error-code constants. Use when asked to remove error codes, inline validation messages, or clean up validators that reference ApiValidationErrorCodes. |
FluentValidation — Inline Messages
When to Use
- Asked to "remove error codes" or "use inline messages" on a FluentValidation validator
- A validator uses
WithErrorCode(ApiValidationErrorCodes.*) followed by WithMessage(ApiValidationErrorCodes.*)
- Migrating away from shared error-code constants to plain descriptive messages
Rules
- Remove every
.WithErrorCode(...) call — do not replace, just delete the line.
- Replace
.WithMessage(ApiValidationErrorCodes.*) with a plain English string describing the rule.
- Remove the
using Unified.Common.Validation; import if ApiValidationErrorCodes is no longer referenced.
- Keep
.When(...) clauses and all other validation logic unchanged.
- End every message with a period for consistency.
Message Conventions
| Rule | Message pattern |
|---|
NotEmpty / NotNull | "{PropertyName} is required." |
MaximumLength(n) | "{PropertyName} must not exceed {n} characters." |
Must(...) date format | "{PropertyName} must be in yyyy-MM-dd format." |
Must(...) cross-field | Describe the business rule, e.g. "ExpiryDate must be on or after EffectiveDate." |
Before / After Example
Before:
using Unified.Common.Validation;
RuleFor(x => x.PositionTypeCode)
.NotEmpty()
.WithErrorCode(ApiValidationErrorCodes.Required)
.WithMessage(ApiValidationErrorCodes.Required)
.MaximumLength(50)
.WithErrorCode(ApiValidationErrorCodes.TooLong)
.WithMessage(ApiValidationErrorCodes.TooLong);
After:
RuleFor(x => x.PositionTypeCode)
.NotEmpty()
.WithMessage("PositionTypeCode is required.")
.MaximumLength(50)
.WithMessage("PositionTypeCode must not exceed 50 characters.");
Checklist
