@nzz/q-server/plugins/core/rendering-info/size-helpers.js

**Maintainer**: [Franco Gervasi](https://github.com/fgervasi)

const Joi = require("../../../helper/custom-joi.js");
const Boom = require("@hapi/boom");

// size, width and height are optional
// if a width or height array is defined the following restrictions apply:
// the array consists of either one (equality or one-sided limitation) or two objects (for a range)
// the respective object has to have a value and a comparison sign,
// if no unit is defined the default value 'px' is assumed.
const sizeValidationObject = {
  width: Joi.array()
    .items(
      Joi.object({
        value: Joi.number().required(),
        comparison: Joi.string()
          .regex(/^(<|>|=){1}$/)
          .required(),
        unit: Joi.string()
          .regex(/^(px|mm)?$/)
          .optional()
      }).required()
    )
    .max(2)
    .optional(),
  height: Joi.array()
    .items(
      Joi.object({
        value: Joi.number().required(),
        comparison: Joi.string()
          .regex(/^(<|>|=){1}$/)
          .required(),
        unit: Joi.string().optional()
      })
    )
    .max(2)
    .optional()
};

function validateDimension(dimension) {
  if (dimension.length === 2) {
    // first, we sort the dimensions
    // this makes it easier for the plausibility checks later on
    dimension = dimension.sort((a, b) => {
      return a.value - b.value;
    });

    const dimensionA = dimension[0];
    const dimensionB = dimension[1];
    if (dimensionA.unit === undefined) {
      dimensionA.unit = "px";
    }
    if (dimensionB.unit === undefined) {
      dimensionB.unit = "px";
    }
    if (dimensionA.unit !== dimensionB.unit) {
      throw Boom.badData("Units are not the same for the given range.");
    }

    // go on with some plausability checks
    const comparisonA = dimensionA.comparison;
    const comparisonB = dimensionB.comparison;
    if (
      comparisonA === comparisonB || // if the same comparison is the same 2 times, it makes no sense
      comparisonA === "=" || // if we have = comparison, it makes no sense to have multiple width definitions
      comparisonB === "=" || // if we have = comparison, it makes no sense to have multiple width definitions
      (comparisonA === "<" && dimensionA.value < dimensionB.value) ||
      (comparisonB === ">" && dimensionB.value > dimensionA.value)
    ) {
      throw Boom.badData(
        "The combination of values and comparison signs does not result in a meaningful range."
      );
    }
  }
  return true;
}

function validateSize(size) {
  if (size.width) {
    try {
      validateDimension(size.width);
    } catch (err) {
      throw err;
    }
  }
  if (size.height) {
    try {
      validateDimension(size.height);
    } catch (err) {
      throw err;
    }
  }
}

module.exports = {
  sizeValidationObject: sizeValidationObject,
  validateDimension: validateDimension,
  validateSize: validateSize
};