Add support for minimumLevel (#233)

* Add support for minimumLevel

* Update Readme.md

Co-authored-by: Matteo Collina <matteo.collina@gmail.com>

Readme.md

@@ -69,6 +69,7 @@ node app.js | pino-pretty
   Default: `level`.
 - `--levelLabel` (`-b`): Output the log level using the specified label.
   Default: `levelLabel`.
+- `--minimumLevel` (`-L`): Hide messages below the specified log level. Accepts a number, `trace`, `debug`, `info`, `warn`, `error`, or `fatal`. If any more filtering is required, consider using [`jq`](https://stedolan.github.io/jq/).
 - `--messageFormat` (`-o`): Format output of message, e.g. `{levelLabel} - {pid} - url:{request.url}` will output message: `INFO - 1123 - url:localhost:3000/test`
   Default: `false`
 - `--timestampKey` (`-a`): Define the key that contains the log timestamp.

bin.js

@@ -35,14 +35,14 @@ args
   .option(['f', 'crlf'], 'Append CRLF instead of LF to formatted lines')
   .option(['e', 'errorProps'], 'Comma separated list of properties on error objects to show (`*` for all properties) (defaults to ``)')
   .option(['l', 'levelFirst'], 'Display the log level as the first output field')
+  .option(['L', 'minimumLevel'], 'Hide messages below the specified log level')
   .option(['k', 'errorLikeObjectKeys'], 'Define which keys contain error objects (`-k err,error`) (defaults to `err,error`)')
   .option(['m', 'messageKey'], 'Highlight the message under the specified key', CONSTANTS.MESSAGE_KEY)
   .option('levelKey', 'Detect the log level under the specified key', CONSTANTS.LEVEL_KEY)
   .option(['b', 'levelLabel'], 'Output the log level using the specified label', CONSTANTS.LEVEL_LABEL)
   .option(['o', 'messageFormat'], 'Format output of message')
   .option(['a', 'timestampKey'], 'Display the timestamp from the specified key', CONSTANTS.TIMESTAMP_KEY)
   .option(['t', 'translateTime'], 'Display epoch timestamps as UTC ISO format or according to an optional format string (default ISO 8601)')
-  .option(['s', 'search'], 'Specify a search pattern according to jmespath')
   .option(['i', 'ignore'], 'Ignore one or several keys: (`-i time,hostname`)')
   .option(['H', 'hideObject'], 'Hide objects from output (but not error object)')
   .option(['S', 'singleLine'], 'Print all non-error objects on a single line')
@@ -57,7 +57,7 @@ args
   .example('cat log | pino-pretty -t', 'To convert Epoch timestamps to ISO timestamps use the -t option')
   .example('cat log | pino-pretty -t "SYS:yyyy-mm-dd HH:MM:ss"', 'To convert Epoch timestamps to local timezone format use the -t option with "SYS:" prefixed format string')
   .example('cat log | pino-pretty -l', 'To flip level and time/date in standard output use the -l option')
-  .example('cat log | pino-pretty -s "msg == \'hello world\'"', 'Only prints messages with msg equals to \'hello world\'')
+  .example('cat log | pino-pretty -L info', 'Only prints messages with a minimum log level of info')
   .example('cat log | pino-pretty -i pid,hostname', 'Prettify logs but don\'t print pid and hostname')
   .example('cat log | pino-pretty --config=/path/to/config.json', 'Loads options from a config file')
 
@@ -67,13 +67,15 @@ let opts = args.parse(process.argv, {
   mri: {
     default: {
       messageKey: DEFAULT_VALUE,
+      minimumLevel: DEFAULT_VALUE,
       levelKey: DEFAULT_VALUE,
       timestampKey: DEFAULT_VALUE
     },
     // NOTE: The following key-value pairs values should be in sync with the
     //       short version values defined in each `args.option([value, key], ...)`
     alias: {
       messageKey: 'm',
+      minimumLevel: 'L',
       timestampKey: 'a'
     }
   }

index.js

@@ -8,7 +8,7 @@ const sonic = require('sonic-boom')
 const sjs = require('secure-json-parse')
 
 const colors = require('./lib/colors')
-const { ERROR_LIKE_KEYS, MESSAGE_KEY, TIMESTAMP_KEY } = require('./lib/constants')
+const { ERROR_LIKE_KEYS, MESSAGE_KEY, TIMESTAMP_KEY, LEVEL_KEY, LEVEL_NAMES } = require('./lib/constants')
 const {
   isObject,
   prettifyErrorLog,
@@ -52,6 +52,7 @@ function prettyFactory (options) {
   const messageKey = opts.messageKey
   const levelKey = opts.levelKey
   const levelLabel = opts.levelLabel
+  const minimumLevel = opts.minimumLevel
   const messageFormat = opts.messageFormat
   const timestampKey = opts.timestampKey
   const errorLikeObjectKeys = opts.errorLikeObjectKeys
@@ -77,6 +78,12 @@ function prettyFactory (options) {
       log = inputData
     }
 
+    if (minimumLevel) {
+      const minimum = LEVEL_NAMES[minimumLevel] || Number(minimumLevel)
+      const level = log[levelKey === undefined ? LEVEL_KEY : levelKey]
+      if (level < minimum) return
+    }
+
     const prettifiedMessage = prettifyMessage({ log, messageKey, colorizer, messageFormat, levelLabel })
 
     if (ignoreKeys) {

test/basic.test.js

@@ -443,6 +443,53 @@ test('basic prettifier tests', (t) => {
     log.info('foo')
   })
 
+  t.test('filter some lines based on minimumLevel', (t) => {
+    t.plan(3)
+    const pretty = prettyFactory({ minimumLevel: 'info' })
+    const expected = [
+      undefined,
+      undefined,
+      `[${epoch}] INFO (${pid} on ${hostname}): baz\n`
+    ]
+    const log = pino({}, new Writable({
+      write (chunk, enc, cb) {
+        const formatted = pretty(chunk.toString())
+        t.equal(
+          formatted,
+          expected.shift()
+        )
+        cb()
+      }
+    }))
+    log.info({ msg: 'foo', level: 10 })
+    log.info({ msg: 'bar', level: 20 })
+    // only this line will be formatted
+    log.info({ msg: 'baz', level: 30 })
+  })
+
+  t.test('filter lines based on minimumLevel using custom levels and level key', (t) => {
+    t.plan(3)
+    const pretty = prettyFactory({ minimumLevel: 20, levelKey: 'bar' })
+    const expected = [
+      undefined,
+      `[${epoch}] DEBUG (${pid} on ${hostname}): bar\n`,
+      `[${epoch}] INFO (${pid} on ${hostname}): baz\n`
+    ]
+    const log = pino({}, new Writable({
+      write (chunk, enc, cb) {
+        const formatted = pretty(chunk.toString())
+        t.equal(
+          formatted,
+          expected.shift()
+        )
+        cb()
+      }
+    }))
+    log.info({ msg: 'foo', bar: 10 })
+    log.info({ msg: 'bar', bar: 20 })
+    log.info({ msg: 'baz', bar: 30 })
+  })
+
   t.test('formats a line with an undefined field', (t) => {
     t.plan(1)
     const pretty = prettyFactory()