Merge pull request #106 from tusharmath/override-meta-params

feat(DownloadFromMTDFile): add support for overriding meta that is be…
tusharmath · Jul 9, 2016 · 414e04c · 414e04c
2 parents 445c429 + 407e6da
commit 414e04c
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Showing 3 changed files with 22 additions and 3 deletions.
diff --git a/README.md b/README.md
@@ -49,7 +49,7 @@ $ mtd --help
 ## Functions
 
 * [CreateMTDFile(options)](#CreateMTDFile) ⇒ <code>[Observable](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/observable.md)</code>
-* [DownloadFromMTDFile(mtdPath)](#DownloadFromMTDFile) ⇒ <code>[Observable](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/observable.md)</code>
+* [DownloadFromMTDFile(mtdPath, [meta])](#DownloadFromMTDFile) ⇒ <code>[Observable](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/observable.md)</code>
 * [FinalizeDownload(params)](#FinalizeDownload) ⇒ <code>[Observable](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/observable.md)</code>
 * [Completion(meta$)](#Completion) ⇒ <code>[Observable](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/observable.md)</code>
 
@@ -187,7 +187,7 @@ information regarding the download appended to the end.
 
 <a name="DownloadFromMTDFile"></a>
 
-## DownloadFromMTDFile(mtdPath) ⇒ <code>[Observable](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/observable.md)</code>
+## DownloadFromMTDFile(mtdPath, [meta]) ⇒ <code>[Observable](https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/observable.md)</code>
 Reads a `.mtd` file and resumes the download from the last successfully saved
 byte.
 
@@ -203,6 +203,7 @@ byte.
 | Param | Type | Description |
 | --- | --- | --- |
 | mtdPath | <code>String</code> | Relative path to the `.mtd` file. |
+| [meta] | <code>Object</code> | Optional meta data to override the one that's being loaded from the `.mtd` file. |
 
 <a name="FinalizeDownload"></a>
 

diff --git a/src/DownloadFromMTDFile.js b/src/DownloadFromMTDFile.js
@@ -27,6 +27,8 @@ import {
  * byte.
  * @function
  * @param {String} mtdPath - Relative path to the `.mtd` file.
+ * @param {Object} [meta] - Optional meta data to override the one that's being
+ * loaded from the `.mtd` file.
  * @return {external:Observable}
  * A {@link https://github.com/tusharmath/muxer multiplexed stream} containing ~
  * - `metaWritten$` - Meta data buffer stream.
@@ -36,7 +38,7 @@ import {
  * - `fdR$` - File Descriptor in `r+` mode.
  * - `meta$` - Download meta information.
  */
-export const DownloadFromMTDFile = R.curry(({FILE, HTTP}, mtdPath) => {
+export const DownloadFromMTDFile = R.curryN(2, ({FILE, HTTP}, mtdPath, _meta) => {
   /**
    * Open file to read+append
    */
@@ -52,6 +54,7 @@ export const DownloadFromMTDFile = R.curry(({FILE, HTTP}, mtdPath) => {
    */
   const metaPosition$ = MetaPosition$({size$})
   const meta$ = ReadJSON$({FILE, fd$, position$: metaPosition$})
+    .map(meta => R.merge(meta, _meta))
 
   /**
    * Make a HTTP request for each thread

diff --git a/test/test.DownloadFromMTDFile.js b/test/test.DownloadFromMTDFile.js
@@ -146,3 +146,18 @@ test('requestCount', t => {
   sh.startScheduler(() => DownloadFromMTDFile(params, './home/file.mtd'))
   t.is(params.HTTP.request.callCount, 3)
 })
+
+test('override meta data', t => {
+  const sh = new TestScheduler()
+  const params = createParams(sh, {
+    url: '/a/b/c',
+    threads: [[0, 10]],
+    offsets: [5]
+  })
+  sh.startScheduler(() => DownloadFromMTDFile(params, './home/file.mtd', {url: '/p/q/r'}))
+  t.is(params.HTTP.request.callCount, 1)
+  t.true(params.HTTP.request.calledWith({
+    url: '/p/q/r',
+    headers: {range: 'bytes=5-10'}
+  }))
+})