wkr-util/esm/validators/validateMustExist.js

Utility library for wkr project.

import {curry, compose, map, get, toInt, isObject, values} from '@cullylarson/f'
import {messageObj, simpleValidationResult} from '@cullylarson/validate'
import {query} from '@cullylarson/mysql'

export default curry((pool, tableName, paramNameToColumnName, value, params) => {
    // if columnInfo is an array, the first item is the column name, the second item
    // is SQL that should be used as the value or value placeholder. It must include a question mark which will be replaced by the value.
    const buildCondition = (columnInfo, value) => {
        const columnName = Array.isArray(columnInfo) ? columnInfo[0] : columnInfo
        const valuePlaceholder = Array.isArray(columnInfo) ? columnInfo[1] : '?'

        return [
            `${columnName} = ${valuePlaceholder}`, // the condition query
            value, // the value to fill in for the '?'
        ]
    }

    const whereInfo = isObject(paramNameToColumnName) && !Array.isArray(paramNameToColumnName)
        ? compose(
            values,
            map((columnInfo, paramName) => buildCondition(columnInfo, params[paramName])),
        )(paramNameToColumnName)
        : [buildCondition(paramNameToColumnName, value)]

    // nothing to check
    if(!whereInfo.length) return simpleValidationResult()

    const where = whereInfo.map(get(0, '')).join(' AND ')
    const whereValues = whereInfo.map(get(1, ''))

    return query(pool, `SELECT COUNT(*) as count FROM ${tableName} WHERE ${where}`, whereValues)
        .then(get(['results', 0, 'count'], 0))
        .then(toInt(0))
        .then(count => {
            return count === 0
                ? simpleValidationResult(messageObj('not-found', 'The entry could not be found.'))
                : simpleValidationResult()
        })
})