add file option to write to fs

Author: joehand

README.md

@@ -19,22 +19,46 @@ var DatJSON = require('dat-json')
 
 var datjson = DatJSON(archive)
 
+datjson.create({title: 'a dat', description: 'exciting'}, function (err) {
+  if (err) throw err
+})
+
+datjson.read(function (err, data) {
+  console.log(data)
+})
+```
+
+Write to a `dat.json` on the file system also:
+
+```js
+var DatJSON = require('dat-json')
+
+var datjson = DatJSON(archive, {file: path.join(dat.path, 'dat.json')})
+
 datjson.create({title: 'a dat', description: 'exciting'}, function (err) {
   if (err) throw err
 })
 ```
 
+**TODO: replace file option with hyperdrive indexing**
+
 ## API
 
-### `var datjson = DatJSON(archive)`
+### `var datjson = DatJSON(archive, [opts])`
+
+create a new datJson db
+
+Options:
+
+* `opts.file` - dat.json file path, updates will be written to file system and archive
 
 #### `datjson.create([data], cb)`
 
-Create a new `dat.json` file in the archive with the default keys (`name`, `url`, `title`, `description`). Pass in any additional data to add on initial create.
+Create a new `dat.json` file in the archive with the default keys (`url`, `title`, `description`). Pass in any additional data to add on initial create.
 
 #### `datjson.write(key, val, cb)` or `datjson.write(data, cb)`
 
-Write a single `key` and `value` or an object, `data`, to the `dat.json` file.
+Write a single `key` and `value` or an object, `data`, to the `dat.json` file. Use `file` option above to also update the file on the file system.
 
 #### `datjson.delete(key, cb)`
 

index.js

@@ -3,8 +3,12 @@ var stringKey = require('dat-encoding').toStr
 var xtend = require('xtend')
 var toiletdb = require('toiletdb')
 
-module.exports = function (archive) {
+module.exports = function (archive, opts) {
+  if (!opts) opts = {}
+
   var db = toiletdb({name: '/dat.json', fs: archive})
+  var fileDb = opts.file ? toiletdb(opts.file) : null
+
   var that = {
     read: function (cb) {
       archive.stat('/dat.json', function (err, stat) {
@@ -16,7 +20,15 @@ module.exports = function (archive) {
       if (!archive.writable) return cb(new Error('Archive not writable'))
       if (typeof key === 'object') return writeAll(key, val) // assume val = cb
       // TODO: validate things
-      db.write(key, val, cb)
+      if (!fileDb) return db.write(key, val, cb)
+
+      // write to file then archive
+      // TODO: use hyperdrive indexing false option, need to talk to mafintosh about
+      //   https://botbot.me/freenode/dat/2017-05-12/?msg=85554242&page=3
+      fileDb.write(key, val, function (err) {
+        if (err) return cb(err)
+        db.write(key, val, cb)
+      })
     },
     delete: db.delete,
     create: function (data, cb) {

test/index.js

@@ -1,3 +1,5 @@
+var fs = require('fs')
+var path = require('path')
 var test = require('tape')
 var hyperdrive = require('hyperdrive')
 var ram = require('random-access-memory')
@@ -45,3 +47,39 @@ test('Write dat.json to archive', function (t) {
     })
   })
 })
+
+test('Write dat.json to file and archive', function (t) {
+  var archive = hyperdrive(ram)
+  var file = path.join(__dirname, 'dat.json')
+  archive.ready(function () {
+    var datjson = datJSON(archive, {file: file})
+    datjson.create(function (err) {
+      t.error(err, 'no error')
+      datjson.write({specialVal: 'cat'}, checkFile)
+
+      function checkFile (err) {
+        t.error(err, 'no error')
+        fs.readFile(file, 'utf-8', function (err, data) {
+          data = JSON.parse(data)
+          t.error(err, 'fs no error')
+          t.ok(data, 'fs has metadata')
+          t.same(data.url, `dat://${archive.key.toString('hex')}`, 'fs url ok')
+          t.same(data.specialVal, 'cat', 'fs has special value')
+          fs.unlinkSync(file)
+          checkRead()
+        })
+      }
+
+      function checkRead (err) {
+        t.error(err, 'no error')
+        datjson.read(function (err, data) {
+          t.error(err, 'no error')
+          t.ok(data, 'has metadata')
+          t.same(data.url, `dat://${archive.key.toString('hex')}`, 'url ok')
+          t.same(data.specialVal, 'cat', 'has special value')
+          t.end()
+        })
+      }
+    })
+  })
+})