/// <reference path="./jasmine-matchers.d.ts" />

export const addMatchers = () => jasmine.addMatchers({
  toHaveText, toHaveCssClass
});

/**
 * `toHaveText()` adapted from https://angular.io/guide/testing
 */
function toHaveText(): jasmine.CustomMatcher {
  return {
    compare(
      actual: any,
      expectedText: string,
      expectationFailOutput?: any
    ): jasmine.CustomMatcherResult {
      const actualText = elementText(actual);
      const pass = actualText.indexOf(expectedText) > -1;
      const message = pass ? '' : composeMessage();
      return { pass, message };

      function composeMessage() {
        const a =
          actualText.length < 100
            ? actualText
            : actualText.substr(0, 100) + '...';
        const efo = expectationFailOutput ? ` '${expectationFailOutput}'` : '';
        return `Expected element to have text content '${expectedText}' instead of '${a}'${efo}`;
      }
    }
  };
}

function elementText(n: any): string {
  if (n instanceof Array) {
    return n.map(elementText).join('');
  }

  if (n.nodeType === Node.COMMENT_NODE) {
    return '';
  }

  if (n.nodeType === Node.ELEMENT_NODE && n.hasChildNodes()) {
    return elementText(Array.prototype.slice.call(n.childNodes));
  }

  if (n.nativeElement) {
    n = n.nativeElement;
  }

  return n.textContent;
}

/**
 * adapted from https://github.com/ng-bootstrap/ng-bootstrap/blob/master/src/test/matchers.ts
 */
function toHaveCssClass(util, customEqualityTests) {
  return { compare: buildError(false), negativeCompare: buildError(true) };

  function buildError(isNot: boolean) {
    return function(actual: HTMLElement, className: string) {
      return {
        pass: actual.classList.contains(className) === !isNot,
        message: `Expected ${actual.outerHTML} ${
          isNot ? 'not ' : ''
        }to contain the CSS class "${className}"`
      };
    };
  }
}