39 lines
842 B
JavaScript
39 lines
842 B
JavaScript
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'use strict';
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const tabsToSpaces = require('convert-to-spaces');
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const generateLineNumbers = (line, around) => {
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const lineNumbers = [];
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const min = line - around;
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const max = line + around;
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for (let lineNumber = min; lineNumber <= max; lineNumber++) {
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lineNumbers.push(lineNumber);
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}
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return lineNumbers;
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};
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module.exports = (source, line, options) => {
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if (typeof source !== 'string') {
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throw new TypeError('Source code is missing.');
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}
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if (!line || line < 1) {
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throw new TypeError('Line number must start from `1`.');
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}
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source = tabsToSpaces(source).split('\n');
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if (line > source.length) {
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return null;
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}
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options = Object.assign({around: 3}, options);
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return generateLineNumbers(line, options.around)
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.filter(line => source[line - 1] !== undefined)
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.map(line => ({line, value: source[line - 1]}));
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};
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