odin-js-fundamentals-part-4/node_modules/object.groupby/test/tests.js

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2024-01-05 19:30:21 +00:00
'use strict';
var inspect = require('object-inspect');
var forEach = require('for-each');
var v = require('es-value-fixtures');
module.exports = function (groupBy, t) {
t.test('callback function', function (st) {
forEach(v.nonFunctions, function (nonFunction) {
st['throws'](
function () { groupBy([], nonFunction); },
TypeError,
inspect(nonFunction) + ' is not a function'
);
});
st.end();
});
t.test('grouping', function (st) {
st.deepEqual(
groupBy([], function () { return 'a'; }),
{ __proto__: null },
'an empty array produces an empty object'
);
var arr = [0, -0, 1, 2, 3, 4, 5, NaN, Infinity, -Infinity];
var parity = function (x) {
if (x !== x) {
return void undefined;
}
if (!isFinite(x)) {
return '∞';
}
return x % 2 === 0 ? 'even' : 'odd';
};
var grouped = {
__proto__: null,
even: [0, -0, 2, 4],
odd: [1, 3, 5],
undefined: [NaN],
'∞': [Infinity, -Infinity]
};
st.deepEqual(
groupBy(arr, parity),
grouped,
inspect(arr) + ' group by parity groups to ' + inspect(grouped)
);
st.deepEqual(
groupBy(arr, function (x, i) {
st.equal(this, undefined, 'receiver is as expected'); // eslint-disable-line no-invalid-this
st.equal(x, arr[i], 'second argument ' + i + ' is ' + inspect(arr[i]));
return 42;
}),
{ __proto__: null, 42: arr },
'thisArg and callback arguments are as expected'
);
st.end();
});
};