Invalid Character error from JSON.parse() when string read from a file

Question

Metro style HTML & javascript app

I created a folder named 'data' at the root of my project. I added a javascript file named x.js using Add | New Item from the Solution Explorer. Within that file I have the following:

[
]

(yes, there is a CRLF between the two brackets)

I use something similar to the following to read and parse the file as json:

Windows.Storage.PathIO.readTextAsync("ms-appx:///data/conference.js", Windows.Storage.Streams.UnicodeEncoding.utf8)
.then(function(s){var o = JSON.parse(s);});

This throws an Invalid Character exception from the JSON.parse(). If I .trim() the string before parsing then there is no error:

var o = JSON.parse(s.trim());

Could PathIO.readTextAsync() be returning the Byte Order Mark?

TIA

-Mike

Answer 1

Mike,

The issue is the CR/LF and that there is no JSON data inside there.  Doing the trim removes the LF.

That said, we should probably handle this better.  I filed a bug on this.

Thanks for finding this!

-Jeff

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Jeff Sanders (MSFT)

Answer 2

PS,

It is in conjunction with the BOM.  You can work around this by opening the file and removing the BOM.

1. Right click on your file
2. Open with
3. Choose: Souce Code (Text) Editor With Encoding
4. For encoding choose: US-ASCII - COdepage 20127

-Jeff

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Jeff Sanders (MSFT)