| 1 | function incrementListIndex(current, dir, opt) {
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| 2 | const len = opt.choices.realLength;
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| 3 | const shouldLoop = 'loop' in opt ? Boolean(opt.loop) : true;
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| 4 | if (dir === 'up') {
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| 5 | if (current > 0) {
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| 6 | return current - 1;
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| 7 | }
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| 8 | return shouldLoop ? len - 1 : current;
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| 9 | }
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| 10 | if (dir === 'down') {
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| 11 | if (current < len - 1) {
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| 12 | return current + 1;
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| 13 | }
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| 14 | return shouldLoop ? 0 : current;
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| 15 | }
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| 16 | throw new Error('dir must be up or down');
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| 17 | }
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| 18 |
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| 19 | module.exports = incrementListIndex;
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