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date format validation
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| const testone = require('@fedeghe/testone'); | |
| const validDate = value => { | |
| const plainValue = value.replace(/[^\d]/g, ' '); | |
| const elements = plainValue.split(/\s/).map(i => parseInt(i, 10)); | |
| // must find month < 13 | |
| const foundMonth = elements.findIndex(e => e > 0 && e < 13); | |
| if (foundMonth < 0) return false; | |
| // must find another value in [1,31] | |
| const foundDate = elements.findIndex( | |
| (e,i) => i != foundMonth && e > 0 && e < 32 | |
| ); | |
| if (foundDate < 0) return false; | |
| // finally must find a YYYY | |
| const foundYear = elements.findIndex(e => e >= 1e3 && e < 1e4); | |
| if (foundYear < 0) return false; | |
| // still the date could be invalid (non leap e.g.) 2011-02-31 | |
| const d = new Date(plainValue), | |
| t = d.setHours(0); | |
| d.setMinutes(0); | |
| d.setSeconds(0); | |
| d.setMilliseconds(0); | |
| return d.getFullYear() === elements[foundYear] && | |
| d.getMonth()+1 === elements[foundMonth] && | |
| d.getDate() === elements[foundDate]; | |
| }; | |
| testone([ | |
| { in: ['2020-12-12'], out: true}, | |
| { in: ['2020-12-31'], out: true}, | |
| { in: ['2023-01-01'], out: true}, | |
| // | |
| { in: ['2020-12-32'], out: false}, | |
| { in: ['2020-13-13'], out: false}, | |
| { in: ['2020-13-13'], out: false}, | |
| { in: ['2020-00-13'], out: false}, | |
| { in: ['999-12-13'], out: false}, | |
| { in: ['10000-12-13'], out: false}, | |
| { in: ['0-12-13'], out: false}, | |
| ], validDate).then(res => { | |
| console.log({validDate: res.passing}) | |
| }) | |
| const validFormat = (format, allowedSep, els = ['YYYY', 'MM', 'DD']) => { | |
| const hasEls = els.every(el => format.includes(el)), | |
| sep = format.replace(/\w/g, '').split(''); | |
| let sepOk = true; | |
| if (allowedSep) sep.forEach(s => { | |
| sepOk &&= allowedSep.includes(s); | |
| }); | |
| return sepOk && sep.length === els.length-1 && | |
| !!hasEls; | |
| }; | |
| testone([ | |
| { in: ['YYYY-MM-DD'], out: true}, | |
| { in: ['YYYY-MM-DD', ['-']], out: true}, | |
| { in: ['MM-DD', ['-'], ['MM', 'DD']], out: true}, | |
| { in: ['YYYY/DD', ['/'], ['YYYY', 'DD']], out: true}, | |
| // | |
| { in: ['YYYY-MM-DD', [';']], out: false}, | |
| { in: ['2020-13-13'], out: false}, | |
| { in: ['MM/DD', ['-'], ['MM', 'DD']], out: false}, | |
| ], validFormat).then(res => { | |
| console.log({validFormat: res.passing}) | |
| }); | |
| function isValidDate(dateString, format, separators, placeholders) { | |
| // Escape special characters in a string for use in a regex | |
| function escapeRegex(str) { | |
| return str.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&'); | |
| } | |
| // Create a regex pattern to match the date format | |
| let separatorPattern = separators.map(escapeRegex).join('|'); | |
| let placeholderPattern = placeholders.map(escapeRegex).join('|'); | |
| // Split the format into components | |
| let formatComponents = format.split(new RegExp(`(${separatorPattern}|${placeholderPattern})`)); | |
| // Build the regex pattern based on the format components | |
| let regexPattern = formatComponents.map(component => { | |
| switch (component) { | |
| case 'DD': | |
| return '(\\d{2})'; | |
| case 'MM': | |
| return '(\\d{2})'; | |
| case 'YYYY': | |
| return '(\\d{4})'; | |
| case 'YY': | |
| return '(\\d{2})'; | |
| default: | |
| return escapeRegex(component); | |
| } | |
| }).join(''); | |
| let dateRegex = new RegExp(`^${regexPattern}$`); | |
| let match = dateString.match(dateRegex); | |
| if (!match) { | |
| return false; | |
| } | |
| // Extract the date components from the match | |
| let dateComponents = {}; | |
| let formatIndex = 1; | |
| formatComponents.forEach(component => { | |
| if (component === 'DD' || component === 'MM' || component === 'YYYY' || component === 'YY') { | |
| dateComponents[component] = match[formatIndex++]; | |
| } | |
| }); | |
| let day = parseInt(dateComponents['DD'], 10); | |
| let month = parseInt(dateComponents['MM'], 10) - 1; // Months are zero-indexed in JavaScript Date | |
| let year = parseInt(dateComponents['YYYY'] || `20${dateComponents['YY']}`, 10); | |
| // Validate the date by creating a Date object and checking its components | |
| let date = new Date(year, month, day); | |
| return date.getFullYear() === year && date.getMonth() === month && date.getDate() === day; | |
| } | |
| // Example usage: | |
| let dateString = "12-05-2024"; | |
| let format = "DD-MM-YYYY"; | |
| let separators = ['-', '/']; | |
| let placeholders = [' ']; | |
| console.log(isValidDate(dateString, format, separators, placeholders)); // Output: true | |
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