Simplify Express.js Validation: Sync Joi and Mongoose Schemas

usages.js

const viewModelProps = {
  title: { type: String, isRequired: true, minLength: 5,  unique: true, index: true },
  category: { type: String, isRequired: true },
}

// in mongoose 
const videoSchema = new mongoose.Schema({
  ...generateSchema(true, viewModelProps),
  duration: {
    type: Number,
    min: 0,
  }});

const Video = mongoose.model('Video', videoSchema);

// in joi
const schema = Joi.object().keys({
  _id: Joi.string().optional(),
  ...generateSchema(false, viewModelProps),
});

validation-helper.js

const isJoiString = (options = {}) => {
 const { minLength = 1, maxLength = 50, required = true } = options;

 let schemaProp = Joi.string().min(minLength).max(maxLength);
 if (required) {
  schemaProp = schemaProp.required();
 }
 return schemaProp;
};

const isMongoString = (options = {}) => {
  const {
    minLength = 1,
    maxLength = 100,
    required = true,
    trim = true,
    ...otherOptions
  } = options;

  return {
    type: String,
    required,
    trim,
    minLength,
    maxLength,
    ...otherOptions,
  };
};

const isString = (isDbSchema, options = {}) => {
 if (isDbSchema) {
  return isMongoString(options);
 } else {
  return isJoiString(options);
 }
};

const generateSchema = (isDb, props) => {
  Object.keys(props).forEach((key) => {
    const propertyOptions = props[key];
    if (propertyOptions.type.name === 'String') {
      schema[key] = isString(isDb, propertyOptions);
    } else {
      // Handle unsupported types - you might want to throw an error here
      throw new Error(`Unsupported type: ${propertyOptions.type}`);
    }
  });
};