98 lines
2.8 KiB
JavaScript
98 lines
2.8 KiB
JavaScript
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'use strict';
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var test = require('tape');
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var reduce = require('..');
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var createItem = function createTestItem() {
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return {
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a: 'a1',
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b: 'b1',
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c: 'c1'
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};
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};
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test('reduce calls each iterator', function (t) {
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var item = createItem();
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var timesCalled = 0;
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var accumulator = { key: '' };
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var expectedKeys = ['a', 'b', 'c'];
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var expectedValues = ['a1', 'b1', 'c1'];
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var expectedAccumulatorKeys = ['', 'a1', 'a1b1', 'a1b1c1'];
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var calledArguments = [];
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var slice = Array.prototype.slice;
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var iterator = function (acc, value, key, list) {
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var expectedKey = expectedKeys[timesCalled];
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var expectedValue = expectedValues[timesCalled];
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var expectedAccumulatorKey = expectedAccumulatorKeys[timesCalled];
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calledArguments.push(slice.apply(arguments));
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t.equal(value, expectedValue, 'value ' + value + ' does not match ' + expectedValue);
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t.equal(key, expectedKey, 'key ' + key + ' does not match ' + expectedKey);
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t.equal(list, item, 'list arg is not correct');
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t.equal(acc.key, expectedAccumulatorKey, 'accumulator key ' + acc.key + ' does not match ' + expectedAccumulatorKey);
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timesCalled += 1;
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acc.key += value;
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return acc;
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};
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var result = reduce(item, iterator, accumulator);
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t.equal(timesCalled, 3, 'iterator was not called thrice');
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t.deepEqual(result, { key: 'a1b1c1' }, 'result is incorrect');
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t.deepEqual(calledArguments[0], [{
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key: 'a1b1c1'
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}, 'a1', 'a', item], 'iterator called with wrong arguments');
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t.deepEqual(calledArguments[1], [{
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key: 'a1b1c1'
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}, 'b1', 'b', item], 'iterator called with wrong arguments');
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t.deepEqual(calledArguments[2], [{
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key: 'a1b1c1'
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}, 'c1', 'c', item], 'iterator called with wrong arguments');
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t.deepEqual(result, {
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key: 'a1b1c1'
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});
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t.end();
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});
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test('reduce calls iterator with correct this value', function (t) {
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var item = createItem();
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var thisValue = {};
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var iterator = function () {
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// eslint-disable-next-line no-invalid-this
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t.equal(this, thisValue, 'this value is incorrect');
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};
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reduce(item, iterator, thisValue, {});
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t.end();
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});
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test('reduce reduces with first value if no initialValue', function (t) {
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var list = [1, 2];
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var iterator = function (sum, v) {
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return sum + v;
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};
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var result = reduce(list, iterator);
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t.equal(result, 3, 'result is incorrect');
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t.end();
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});
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test('reduce throws a TypeError when an invalid iterator is provided', function (t) {
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t['throws'](function () { reduce([1, 2]); }, TypeError, 'requires a function');
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t.end();
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});
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test('reduce has a length of 2, mimicking spec', function (t) {
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t.equal(reduce.length, 2, 'reduce has a length of 2');
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t.end();
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});
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