URL parsing bug (?) causes "does not appear to be a Shiny application" error

[jaeddy]

I'm attempting to run shinycannon locally on Mac OS Mojave (10.14.4) — if relevant, my Java version is 1.8.0_121, and Shiny version is 1.3.2.

The error indicates that the local URL "does not appear to be a Shiny application" (it definitely is, normally hosted on shinyapps.io).

$ shinycannon --debug-log --overwrite-output recording.log http://127.0.0.1:3573
[Fatal Error] :964:100: Attribute name "selected" associated with an element type "option" must be followed by the ' = ' character.
2019-07-17 10:23:24.391 ERROR [thread00] - Target URL http://127.0.0.1:3573 does not appear to be a Shiny application.

It seems like the error is related to shinyJsNode, but the pattern it appears to be checking for is in the app source:

<script src="shared/shiny.min.js"></script>

I think there might be a failure with parsing the HTML somewhere before this check, given the message:

[Fatal Error] :964:100: Attribute name "selected" associated with an element type "option" must be followed by the ' = ' character.

Here's the line in question — produced without modification by the Shiny selectInput() function (and as far as I can tell, totally valid HTML):

<option value="Immune Cell Proportion - Common Lymphoid and Myeloid Cell Derivative Class" selected>Immune Cell Proportion - Common Lymphoid and Myeloid Cell Derivative Class</option>

If I had to guess, the error is happening here — but there's no trace associated with the error (and I don't know Kotlin).

[alandipert]

Hi, thanks for the report, your diagnosis seems right to me. I'm thinking maybe the best fix is to not parse the HTML, but just search for shiny.js or shiny.min.js in the HTML string.

[alandipert]

@jaeddy When you have an opportunity please try with the latest shinycannon. This should be fixed. Thanks again for the report 👍

[jaeddy]

Thanks! I'll check it out. 🙂