@giro3d/giro3d/utils/tsutils.js

A JS/WebGL framework for 3D geospatial data visualization

/*
 * Copyright (c) 2015-2018, IGN France.
 * Copyright (c) 2018-2026, Giro3D team.
 * SPDX-License-Identifier: MIT
 */

export const nameof = name => name;

/**
 * Extracts the property from the object, throwing an error if it is undefined.
 *
 * @throws if obj.prop is undefined.
 */
export function defined(obj, prop) {
  const val = obj[prop];
  if (val === undefined) {
    throw new Error(`missing '${prop}' parameter`);
  }
  return val;
}

/**
 * Returns the non-nullish value or throws an exception if the object is nullish.
 * @param obj - The object to evaluate for nullishness.
 * @param msg - The optional error message.
 * @returns The {@link NonNullable} equivalent of the input value.
 */
export function nonNull(obj, msg) {
  if (obj == null) {
    throw new Error(msg ?? 'non-null assertion failed');
  }
  return obj;
}

/**
 * Returns the non-nullish and non-empty value or throws an exception if the object is nullish or
 * an empty array.
 * @param obj - The object to evaluate for nullishness or emptyness.
 * @param msg - The optional error message.
 * @returns The {@link NonNullable} equivalent of the input value.
 */
export function nonEmpty(obj, msg) {
  if (obj == null) {
    throw new Error(msg ?? 'non-null assertion failed');
  }
  if (obj.length === 0) {
    throw new Error(msg ?? 'array is empty');
  }
  return obj;
}
export function isIterable(obj) {
  if (obj == null) {
    return false;
  }
  // @ts-expect-error expression is of any type
  return typeof obj[Symbol.iterator] === 'function';
}

/**
 * Applies the callback to the input if it is a single object, or on its items if it is an iterator.
 */
export function map(input, callback) {
  if (isIterable(input)) {
    for (const item of input) {
      callback(item);
    }
  } else {
    callback(input);
  }
}