workaround typedarray subarray bug that breaks content-type detection in some cases

Author: nfriedly

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+### v0.25.1
+* Workaround for browser bug that was breaking automatic content-type detection in certain cases
+
 ### v0.25.0
 * Fixed bug with recognizeStream failing to auto-detect content-type
 * RecognizeStream no longer sets any default options

speech-to-text/recognize-stream.js

@@ -407,7 +407,9 @@ RecognizeStream.prototype.promise = require('./to-promise');
 
 
 RecognizeStream.getContentType = function(buffer) {
-  return contentType(buffer.slice(0, 4).toString());
+  // the substr really shouldn't be necessary, but there's a bug somewhere that can cause buffer.slice(0,4) to return
+  // the entire contents of the buffer, so it's a failsafe to catch that
+  return contentType(buffer.slice(0, 4).toString().substr(0,4));
 };