Support SonicBoom as a destination (#256)

Readme.md

@@ -207,6 +207,13 @@ The options accepted have keys corresponding to the options described in [CLI Ar
   ignore: 'pid,hostname', // --ignore
   hideObject: false, // --hideObject
   singleLine: false, // --singleLine
+
+  // The file or file descriptor (1 is stdout) to write to
+  destination: 1,
+
+  // Alternatively, pass a `sonic-boom` instance (allowing more flexibility):
+  // destination: new SonicBoom({ dest: 'a/file', mkdir: true })
+
   customPrettifiers: {}
 }
 ```

index.js

@@ -183,7 +183,18 @@ function build (opts = {}) {
       }
     })
 
-    const destination = sonic({ dest: opts.destination || 1, sync: false })
+    let destination
+
+    if (typeof opts.destination === 'object' && typeof opts.destination.write === 'function') {
+      destination = opts.destination
+    } else {
+      destination = sonic({
+        dest: opts.destination || 1,
+        append: opts.append,
+        mkdir: opts.mkdir,
+        sync: false
+      })
+    }
     /* istanbul ignore else */
     if (destination.fd === 1) {
       // We cannot close the output

test/basic.test.js

@@ -5,9 +5,17 @@ const os = require('os')
 const test = require('tap').test
 const pino = require('pino')
 const dateformat = require('dateformat')
+const path = require('path')
+const rimraf = require('rimraf')
+const { join } = require('path')
+const fs = require('fs')
 const pinoPretty = require('..')
+const SonicBoom = require('sonic-boom')
 const _prettyFactory = pinoPretty.prettyFactory
 
+// Disable pino warnings
+process.removeAllListeners('warning')
+
 function prettyFactory (opts) {
   if (!opts) {
     opts = { colorize: false }
@@ -748,5 +756,56 @@ test('basic prettifier tests', (t) => {
     t.doesNotThrow(pinoPretty)
   })
 
+  t.test('stream usage', async (t) => {
+    t.plan(1)
+    const tmpDir = path.join(__dirname, '.tmp_' + Date.now())
+    t.teardown(() => rimraf(tmpDir, noop))
+
+    const destination = join(tmpDir, 'output')
+
+    const pretty = pinoPretty({
+      singleLine: true,
+      colorize: false,
+      mkdir: true,
+      append: false,
+      destination: new SonicBoom({ dest: destination, async: false, mkdir: true, append: true }),
+      customPrettifiers: {
+        upper: val => val.toUpperCase(),
+        undef: () => undefined
+      }
+    })
+    const log = pino(pretty)
+    log.info({ msg: 'message', extra: { foo: 'bar', number: 42 }, upper: 'foobar', undef: 'this will not show up' })
+
+    await watchFileCreated(destination)
+
+    const formatted = fs.readFileSync(destination, 'utf8')
+
+    t.equal(formatted, `[${epoch}] INFO (${pid} on ${hostname}): message {"extra":{"foo":"bar","number":42},"upper":"FOOBAR"}\n`)
+  })
+
   t.end()
 })
+
+function watchFileCreated (filename) {
+  return new Promise((resolve, reject) => {
+    const TIMEOUT = 2000
+    const INTERVAL = 100
+    const threshold = TIMEOUT / INTERVAL
+    let counter = 0
+    const interval = setInterval(() => {
+      // On some CI runs file is created but not filled
+      if (fs.existsSync(filename) && fs.statSync(filename).size !== 0) {
+        clearInterval(interval)
+        resolve()
+      } else if (counter <= threshold) {
+        counter++
+      } else {
+        clearInterval(interval)
+        reject(new Error(`${filename} was not created.`))
+      }
+    }, INTERVAL)
+  })
+}
+
+function noop () {}