Script name can change when a file fails to load

[microbit-rosslowe]

When a module (with the "magic comment") is dragged & dropped into the editor it is added to the filesystem and doesn't replace the user's code in the editor, as expected. However, the script name will change to the name of the loaded file:

Additionally, when using older versions of the editor (e.g. https://python.microbit.org/v/1.0), trying to load an invalid hex file (e.g. from the newer version of the editor) will not load (as expected), but the script name will still change.

Completion criteria - if a user attempts to upload a file and it doesn't replace the main editor code, it also shouldn't change the script name.

[PropGit]

This same behavior (script name changing) also occurs if the module (with "magic comment") is dragged & dropped onto the file management (Load button) dialog's drop target.

[microbit-carlos]

Commit e765ea2 from the filesystem branch removed the setName() calls before processing the python or hex files, so that it only sets the Script Name editor when it confirms the file should be loaded.
Commit 094189b produced when merging the 83-remove-script-description branch (PR #98) had a conflict with this change and the lines were added again

We should create a new commit on top of the beta-integration branch to remove these lines:

PythonEditor/python-main.js

Line 609 in aacf1fc

setName(f.name.replace('.py', ''));

PythonEditor/python-main.js

Line 615 in aacf1fc

setName(f.name.replace('.hex', ''));

PythonEditor/python-main.js

Line 801 in aacf1fc

setName(file.name.replace('.py', ''));

PythonEditor/python-main.js

Line 807 in aacf1fc

setName(file.name.replace('.hex', ''));

@microbit-rosslowe Could you create a branch from beta-integration with this fix and submit a PR against the beta-integration branch (instead of master)?
It'd be great if you could also update the puppeteer tests to check for this condition as part of this task.

[microbit-rosslowe]

When this change is made:

• default script name is 'microbit'
• file is loaded with the "magic comment" and appears in filesystem. Script name doesn't change
• file is loaded without the "magic comment" and replaces the main script. Script name does change, but not to the uploaded file name but to main(.py)

@microbit-carlos is this the expected behaviour? I think it makes sense that any loaded file is called main.py as this is how it appears in the filesystem, but having a default name of 'microbit' seems a little confusing.

[PropGit]

@microbit-rosslowe and @microbit-carlos - This probably warrants starting another dedicated issue for discussion, but for what it's worth now, here are my thoughts:

• the default name that appears when the editor site is first loaded (or refreshed) in the browser can be anything: microbit, example, sample, whatever you decide
• if the user's script must be main.py in the file system because that's what's required by the micro:bit for proper operation, it's fine to download/flash it as main.py
• if the user Load's or drags/drops a user script into the editor, I suggest the Script Name should naturally become the name of that file, but appear in the micro:bit file system as main.py if the above point is true

The reason for the last point is:

• It's natural for the user to expect to see their newly-loaded file's name appear in the Script Name field
• When they click the Save button, it makes more sense for the browser to store it as a similar name to the original the user loaded
• Ultimately, it may later be possible for the site to Save scripts in a better, more filesystem aware fashion (Chrome Apps can- and Google is merging Chrome App features into PWA features to sway developers in that direction, so file system management may one day be possible too) - and using the user's loaded Script Name allows for a natural progression in that matter

[microbit-carlos]

Right, we need to fix that.

If the user loads a file named foo.py then the "script name" should be foo. Internally the filesystem would rename the file to main.py but this is invisible to the user, the "script name" and filenames on the user computer should be the same. This is also important so that the downloaded hex file keeps the name foo.hex, otherwise we lose hat information.

[microbit-rosslowe]

I think the issue is here:

PythonEditor/python-main.js

Line 356 in aacf1fc

filename = isModule ? filename : 'main.py';

Fix in #119

Dragging & dropping into editor, into the grey box, and by the 'or pick a file' option:

• Dropping filename.py without magic comment should replace name with "filename"
• Dropping filename.py with magic comment should not replace name; filename.py should appear in filesystem
• Dropping filename.hex should load the file and replace the filename with "filename"
• Adding invalid files (empty file, bad hex files) should not replace filename

[microbit-carlos]

This fix has been implemented in two PRs:

• Fix script name change on file load #119 to the beta-integration branch that fixes an older merge conflict.
• Script name change on file load (fs) #124 to the filesystem branch that sets the right name on the Script Name input (instead of main).

[PropGit]

Thanks @microbit-carlos

[microbit-carlos]

PRs have been merged into their respective branches. When beta is deployed again this fix will be included.

[microbit-carlos]

Fix has been deployed to https://python.microbit.org/v/beta, thanks @PropGit and @microbit-rosslowe.