add option to ensure directory for dest file exists (#79)

- mkdir:true ensures the directory exists using fs.mkdir with the recursive option
- mkdir:false does not check for the existence of the directory (default)

README.md

@@ -58,10 +58,11 @@ The options are:
 * `fd`: a file descriptor, something that is returned by `fs.open` or
    `fs.openSync`.
 * `dest`: a string that is a path to a file to be written to (mode controlled by the `append` option).
-* `minLength`: the minimum lenght of the internal buffer that is
+* `minLength`: the minimum length of the internal buffer that is
   required to be full before flushing.
 * `sync`: perform writes synchronously (similar to `console.log`).
-* `append`: appends writes to dest file instead of truncating it (default `true`)
+* `append`: appends writes to dest file instead of truncating it (default `true`).
+* `mkdir`: ensure directory for dest file exists when `true` (default `false`).
 
 For `sync:false`  a `SonicBoom` instance will emit the `'ready'` event when a file descriptor is available. 
 For `sync:true` this is not relevant because the `'ready'` event will be fired when the `SonicBoom` instance is created, before it can be subscribed to. 

index.js

@@ -3,6 +3,7 @@
 const fs = require('fs')
 const EventEmitter = require('events')
 const inherits = require('util').inherits
+const path = require('path')
 
 const BUSY_WRITE_TIMEOUT = 100
 
@@ -64,16 +65,23 @@ function openFile (file, sonic) {
     }
   }
 
+  const mode = sonic.append ? 'a' : 'w'
   if (sonic.sync) {
     try {
-      const fd = fs.openSync(file, sonic.append ? 'a' : 'w')
+      if (sonic.mkdir) fs.mkdirSync(path.dirname(file), { recursive: true })
+      const fd = fs.openSync(file, mode)
       fileOpened(null, fd)
     } catch (err) {
       fileOpened(err)
       throw err
     }
+  } else if (sonic.mkdir) {
+    fs.mkdir(path.dirname(file), { recursive: true }, (err) => {
+      if (err) return fileOpened(err)
+      fs.open(file, mode, fileOpened)
+    })
   } else {
-    fs.open(file, sonic.append ? 'a' : 'w', fileOpened)
+    fs.open(file, mode, fileOpened)
   }
 }
 
@@ -82,7 +90,7 @@ function SonicBoom (opts) {
     return new SonicBoom(opts)
   }
 
-  let { fd, dest, minLength, sync, append = true } = opts || {}
+  let { fd, dest, minLength, sync, append = true, mkdir } = opts || {}
 
   fd = fd || dest
 
@@ -95,10 +103,10 @@ function SonicBoom (opts) {
   this._asyncDrainScheduled = false
   this.file = null
   this.destroyed = false
+  this.minLength = minLength || 0
   this.sync = sync || false
   this.append = append || false
-
-  this.minLength = minLength || 0
+  this.mkdir = mkdir || false
 
   if (typeof fd === 'number') {
     this.fd = fd

test.js

@@ -275,6 +275,35 @@ function buildTests (test, sync) {
     })
   })
 
+  test('mkdir', (t) => {
+    t.plan(4)
+
+    const dest = path.join(file(), 'out.log')
+    const stream = new SonicBoom({ dest, mkdir: true, sync })
+
+    stream.on('ready', () => {
+      t.pass('ready emitted')
+    })
+
+    t.ok(stream.write('hello world\n'))
+
+    stream.flush()
+
+    stream.on('drain', () => {
+      fs.readFile(dest, 'utf8', (err, data) => {
+        t.error(err)
+        t.equal(data, 'hello world\n')
+        stream.end()
+        // put file where teardown can access it
+        const { dir, base } = path.parse(dest)
+        const tmpDir = dir + '~'
+        fs.renameSync(dir, tmpDir)
+        fs.renameSync(path.join(tmpDir, base), dir)
+        fs.rmdirSync(tmpDir)
+      })
+    })
+  })
+
   test('flush', (t) => {
     t.plan(5)
 

types/index.d.ts

@@ -12,6 +12,7 @@ export type SonicBoomOpts = {
     minLength?: number
     sync?: boolean
     append?: boolean
+    mkdir?: boolean
 }
 
 export class SonicBoom extends EventEmitter {

types/index.test-d.ts

@@ -29,6 +29,6 @@ sonic.end();
 
 sonic.destroy();
 
-const extraSonic = new SonicBoom({fd: 1, minLength: 0, sync: true, append: true});
+const extraSonic = new SonicBoom({fd: 1, minLength: 0, sync: true, append: true, mkdir: true});
 
 extraSonic.write('extra sonic\n');