text: /* eslint no-shadow: 0 */
  
  const test = require("tap").test;
  const ss = require("../");
  
  test("interquartile range (iqr)", function (t) {
      // Data and results from
      // [Wikipedia](http://en.wikipedia.org/wiki/Quantile#Quantiles_of_a_population)
      t.test("can get proper iqr of an even-length list", function (t) {
          const even = [3, 6, 7, 8, 8, 10, 13, 15, 16, 20];
          t.equal(
              ss.quantile(even, 0.75) - ss.quantile(even, 0.25),
              ss.iqr(even)
          );
          t.end();
      });
  
      t.test("can get proper iqr of an odd-length list", function (t) {
          const odd = [3, 6, 7, 8, 8, 9, 10, 13, 15, 16, 20];
          t.equal(ss.quantile(odd, 0.75) - ss.quantile(odd, 0.25), ss.iqr(odd));
          t.end();
      });
  
      t.test("an iqr of a zero-length list cannot be calculated", function (t) {
          t.throws(function () {
              ss.iqr([]);
          });
          t.end();
      });
      t.end();
  });
  