Merge pull request #1149 from log4js-node/migrate-daysToKeep-to-numBa…

…ckups

chore(deps): migrated from daysToKeep to numBackups due to streamroller@^3.0.0

docs/dateFile.md

@@ -15,7 +15,7 @@ Any other configuration parameters will be passed to the underlying [streamrolle
 * `flags` - `string` (default 'a')
 * `compress` - `boolean` (default false) - compress the backup files during rolling (backup files will have `.gz` extension)
 * `alwaysIncludePattern` - `boolean` (default false) - include the pattern in the name of the current log file as well as the backups.
-* `daysToKeep` - `integer` (default 0) - if this value is greater than zero, then files older than that many days will be deleted during log rolling.
+* `numBackups` - `integer` (default 0) - if this value is greater than zero, then files older than that many days will be deleted during log rolling.
 * `keepFileExt` - `boolean` (default false) - preserve the file extension when rotating log files (`file.log` becomes `file.2017-05-30.log` instead of `file.log.2017-05-30`).
 
 The `pattern` is used to determine when the current log file should be renamed and a new log file created. For example, with a filename of 'cheese.log', and the default pattern of `.yyyy-MM-dd` - on startup this will result in a file called `cheese.log` being created and written to until the next write after midnight. When this happens, `cheese.log` will be renamed to `cheese.log.2017-04-30` and a new `cheese.log` file created. The appender uses the [date-format](https://github.com/nomiddlename/date-format) library to parse the `pattern`, and any of the valid formats can be used. Also note that there is no timer controlling the log rolling - changes in the pattern are determined on every log write. If no writes occur, then no log rolling will happen. If your application logs infrequently this could result in no log file being written for a particular time period.

examples/date-file-rolling.js

@@ -5,7 +5,7 @@ const log4js = require('../lib/log4js');
 log4js.configure({
   appenders: {
     file: {
-      type: 'dateFile', filename: 'thing.log', daysToKeep: 3, pattern: '.mm'
+      type: 'dateFile', filename: 'thing.log', numBackups: 3, pattern: '.mm'
     }
   },
   categories: {

types/log4js.d.ts

@@ -189,7 +189,7 @@ export interface DateFileAppender {
   // keep the file extension when rotating logs
   keepFileExt?: boolean;
   // if this value is greater than zero, then files older than that many days will be deleted during log rolling.(default 0)
-  daysToKeep?: number;
+  numBackups?: number;
 }
 
 export interface LogLevelFilterAppender {