These files originate from the following repositories:

- https://github.com/RaspberryPiFoundation/pygal.js
- https://github.com/RaspberryPiFoundation/sense_hat
- https://github.com/raspberryPiFoundation/turtle

They were created as part of the python-execution-prototypes project:

https://github.com/RaspberryPiFoundation/python-execution-prototypes

https://github.com/RaspberryPiFoundation/python-execution-prototypes/blob/gh-pages/pyodide/webworker.js

Previously, I thought we needed to set these HTTP headers for the web
worker to enable SharedArrayBuffer usage, but we actually need to set
them for requests to the top-level web page. Therefore, ensure the
crossorigin attribute is added to script/link tags for cross-origin
resources.

The worker and its dependencies (pygal / _internal_sense_hat) use ES6
so we need to make sure this is transpiled as part of the standard
webpack build so that it works with all browsers.

…rams

https://pyodide.org/en/stable/usage/api/js-api.html#pyodide.FS

In the future, we could open this up to support other file types
(not just .py, .txt and .csv) and we could allow users to create files
with Python and then save the result to a component in the project, e.g.
to display an image of the Mandelbrot set.

I originally tried implementing this with redux by dispatching an event
containing the ‘content’ object but this isn’t always serialisable, e.g.
for turtle it is a JavaScript Map object. Redux prints a warning if the
object isn’t serialisable. Therefore, instead, use a channel pattern
that allows the sub-component (VisualOutput) to subscribe to the
handleVisual method calls and update its DOM.

https://github.com/RaspberryPiFoundation/python-execution-prototypes/tree/c07359a044023082f56da4d92c32774a7bf01009

Most of this code was copied from PythonRunner.js and then adapted to
implement the handleInput function and set the stdinBuffer array. See
this commit for more information:

RaspberryPiFoundation/python-execution-prototypes@42a7001

Previously, if you ran the following program in the editor using Pyodide
there was no way to cleanly exit:

```python
import sys

for line in sys.stdin:
    print(line)
```

This wasn’t an issue before because Skulpt only supported the input()
function which scans to the end of the line and does not look for EOF
when the standard input is closed.

To support this, add the ability to press control-d which sets the first
element in the stdinBuffer to -1. This signals to the worker that stdin
is closed, which it signals to Pyodide by returning 0 from read(buffer).

These keys are used for copying and undoing on Windows.

…nner.jsx

Previously, we had to manually add ?show_visual_output=true to the URL
to show the pane. We now set showVisual to true when the first
handleVisual message is received and use a ‘showing’ state variable on
the visual objects to determine whether we have already rendered the
visual to avoid re-renders.

Jest doesn’t support Web Workers and was erroring because the
importScripts function isn’t available. Best practice seems to be to
mock the module and returned canned responses. Currently, we don’t have
Jest tests for the experimental PyodideRunner.js so an empty
implementation is sufficient but we could change this later.

https://stackoverflow.com/questions/42567535#answer-62436219

These ternaries were copied over from PythonRunner.