Blocks move when a project is reloaded

[martinwork]

Describe the bug

Arising from support ticket https://support.microbit.org/helpdesk/tickets/82439 (private)

After creating a project with blocks neatly aligned, the blocks move in an apparently unpredictable way when the project is reloaded.

The movement seems to vary - does it depend on which block was moved last?

The moving blocks move across more on each reload.

I don't know if functions are essential - but the example in the ticket has functions.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://makecode.microbit.org/_hLc2Ve1zYbEz
2. Position blocks as below
3. Visit Home and reload the project
4. See error

Expected behavior
Blocks don't change position.

Screenshots
Before reload

After reload

micro:bit version (please complete the following information):
not hardware related

Desktop (please complete the following information):

• OS: [e.g. iOS] Windows 10
• Browser [e.g. chrome, safari] Chrome
• Version [e.g. 22] 128

[martinwork]

Related to this, though not a regression, I don't think... Should I create a separate issue?

Create a new project

Reload it - border is smaller

===========================

Sometimes there's no border...

becomes

==========================

Or a border on one side...

becomes

[riknoll]

i've run into this; seems like the blockly xml loader now likes to bump blocks when parsing the xml file which causes these little nudges to happen.

the behavior in your second comment, however, is how it's always been iirc. we've always adjusted the workspace to align everything to the top-left when loading a project

[martinwork]

Thanks @riknoll I suppose users want to lay out blocks in neat columns and rows and not have that undone with overlapping blocks when the project is reloaded.

The second part is not new, but I noticed it again while looking at the first thing and thought it might be related. I had two thoughts:

• the border of a new project and a reloaded project should be the same width
• no border on either or both sides doesn't look right

[riknoll]

i agree that the nudging behavior is something we should fix, but i believe that we made the aligning to the top-left change in response to feedback from user testing. people were getting "lost" when they opened large projects iirc

[martinwork]

OK, I don't feel strongly about the the border behaviour, which has clearly stood the test of time!

[martinwork]

@riknoll But I don't understand why this issue about blocks moving on reload was removed from the hotfix milestone. Was that a mistake because I've confused the issue?

[Vegz78]

@riknoll But I don't understand why this issue about blocks moving on reload was removed from the hotfix milestone. Was that a mistake because I've confused the issue?

I concur! Something is rotten in the new state of Denmark!

Especially when reloading back to block based code from text based ("JavaScript"), the code reappears as if it has been randomly drawn from a tombola...:

1. Finished project:
   

2. Reloaded from .hex file:
   

3. Returning from the "JavaScript" editor (tombola-effect, comments hidden and also added two variable declarations in grey blocks...):
   

Related?: #5959

[martinwork]

Also reported in support ticket https://support.microbit.org/helpdesk/tickets/83796 (private) that, paraphrasing, when the page is reloaded, blocks move around and often end up overlapping.