@txmo-dev/midas-validation

TypeScript mirror of Midas.Validation — reusable validation rules and helpers for the Midas HMS ecosystem.

Includes built-in rules for Ghana phone numbers, NHIS IDs, email addresses, PHI field masking, and data subject rights types.

Installation

npm install @txmo-dev/midas-validation

Usage

Functional style (lightweight)

import { validate, Rules } from '@txmo-dev/midas-validation';

const result = validate(formData, {
  phone: [Rules.notEmpty, Rules.ghanaPhone],
  email: [Rules.email],
  nhisId: [Rules.nhisId],
  dateOfBirth: [Rules.notFutureDate],
});

if (!result.isValid) {
  console.log(result.errors);
  // [{ field: 'phone', messages: ['phone must be a valid Ghana phone number'] }]
}

Throw on failure

import { validateOrThrow } from '@txmo-dev/midas-validation';

validateOrThrow(formData, {
  phone: [Rules.notEmpty, Rules.ghanaPhone],
});
// Throws MidasValidationError if invalid

Class-based validator (mirrors C# MidasValidator<T>)

import { MidasValidator } from '@txmo-dev/midas-validation';

class RegisterPatientValidator extends MidasValidator<RegisterPatientCommand> {
  constructor() {
    super();
    this.ruleFor('phone', (cmd) => cmd.phone, [this.ghanaPhone()]);
    this.ruleFor('nhisId', (cmd) => cmd.nhisId, [this.nhisId()]);
    this.ruleFor('email', (cmd) => cmd.email, [this.emailAddress()]);
    this.ruleFor('firstName', (cmd) => cmd.firstName, [this.notEmpty(), this.maxLength(100)]);
  }
}

const validator = new RegisterPatientValidator();
validator.validateOrThrow(command);

PHI masking

import { maskPhi, isPhiField, PHI_FIELDS } from '@txmo-dev/midas-validation';

maskPhi('John Mensah', 'firstName');   // 'J*** M***'
maskPhi('0241234567', 'phone');        // '024***567'
maskPhi('[email protected]', 'email'); // 'j***@***.com'
maskPhi('1990-03-15', 'dateOfBirth'); // '****-**-15'

isPhiField('nhisId');    // true
isPhiField('clinicId');  // false

API

Standalone rules

| Rule | Description | |------|-------------| | Rules.notEmpty(field, value) | Field must not be empty | | Rules.ghanaPhone(field, value) | Valid Ghana mobile number (0XXXXXXXXX) | | Rules.nhisId(field, value) | Valid NHIS ID (6–20 alphanumeric) | | Rules.email(field, value) | Valid email address | | Rules.notFutureDate(field, value) | Date must not be in the future |

Functions

| Function | Description | |----------|-------------| | validate(value, rules) | Validate an object against field rules | | validateOrThrow(value, rules) | Validate and throw MidasValidationError on failure |

PHI

| Export | Description | |--------|-------------| | PHI_FIELDS | Canonical list of PHI field names | | isPhiField(name) | Returns true if the field is PHI | | maskPhi(value, fieldType) | Mask a PHI value for safe display |

Classes

| Export | Description | |--------|-------------| | MidasValidator<T> | Abstract base validator with built-in rule helpers | | MidasValidationError | Error thrown by validateOrThrow |

Compliance

• HIPAA 45 CFR §164.514(b) — PHI field definitions
• Ghana NDPA 2023 — Data subject rights
• GDPR Art. 5 — Data minimisation (PHI masking)