@waiting/log/dist/lib/localstorage.js

Lightweight logging for browser

import { isLocalStorageKey, isLogLevelToPrune, isTimeToPrune, validateStoragePrefix } from './util'
/**
 * Save message into LocalStorage
 *
 * @returns key of LocalStorage item, blank if 'silent'
 */
export function localSave(level, data, prefix, maxLen) {
    /* istanbul ignore else */
    if (level === 'silent') {
        return ''
    }
    const time = new Date().toISOString()
    const key = `${prefix}-${level}-${time}`

    save(key, data, maxLen)
    return key
}
function save(key, data, maxLen) {
    let cont = data

    /* istanbul ignore else */
    if (typeof data === 'string' && data.length > maxLen) {
        cont = data.slice(0, maxLen) + ' ...'
    }
    const content = JSON.stringify(cont)

    /* istanbul ignore else */
    if (typeof localStorage === 'object') {
        try {
            localStorage.setItem(encodeURIComponent(key), content)
        }
        catch (ex) {
            console.error(ex)
        }
    }
}
/**
 * Remove expiry logs in LocalStorage.
 * If level omit prune all leves
 *
 * @param storagePrefix
 * @param pruneTime - delte logs in LocalStorage before this Time
 * @param logLevel
 */
export function pruneLogs(storagePrefix, pruneTime, pruneLogLevel) {
    /* istanbul ignore next */
    if (typeof localStorage !== 'object') {
        return
    }
    validateStoragePrefix(storagePrefix)
    const count = localStorage.length

    /* istanbul ignore next */
    if (!count) {
        return
    }
    const encodeKeys = new Array(count)

    // Caution: retrieve keys before delte!!
    // tslint:disable-next-line:prefer-for-of
    for (let i = 0; i < count; i++) {
        // format: <prefix>-<level>-<ISOString>
        // eg: logs-debug-2018-09-02T12:22:22.775Z
        const encodeKey = localStorage.key(i)

        /* istanbul ignore if */
        if (!encodeKey) {
            continue
        }
        else {
            encodeKeys[i] = encodeKey
        }
    }
    // tslint:disable-next-line:prefer-for-of
    for (let i = 0; i < count; i++) {
        const encodeKey = encodeKeys[i]
        const key = decodeURIComponent(encodeKey)

        /* istanbul ignore else */
        if (!isLocalStorageKey(key, storagePrefix)) {
            continue
        }
        const arr = key.split('-')
        const logLevel = arr[1]
        const time = arr.slice(2).join('-')

        /* istanbul ignore else */
        if (!isLogLevelToPrune(logLevel, pruneLogLevel)) {
            continue
        }
        /* istanbul ignore else */
        if (!isTimeToPrune(time, pruneTime)) {
            continue
        }
        localStorage.removeItem(encodeKey)
    }
}