Fix hotswapping modules (No longer working in 0.12)

[cloutiertyler]

No description provided.

[bfops]

I will try to repro this; I doubt I am the right person to actually fix the issue.

[bfops]

A minimal test of hotswapping has worked for me:

1. spacetime init --lang rust my_new_project
2. spacetime publish -s local test-project
3. Run in another terminal: spacetime subscribe -s local test-project 'select * from person'
4. spacetime call -s local test-project add Person1
5. Change a log message -> spacetime publish -s local test-project
6. spacetime call -s local test-project add Person2
7. Observe the log message from before and after the hotswap via spacetime logs -s local test-project
8. Observe that the subscribe saw both rows

[bfops]

Reassigning to keep investigating. We have a repro using clockworklabs/SpacetimeDBCircleGame#2; specifically, by switching the food count and trying to re-publish the module.. but it's unclear why it's failing, and attempting a more minimal repro does not work.

[bfops]

This is the smallest repro I could come up with.

Module code:

use spacetimedb::{ReducerContext, SpacetimeType, Table};

#[spacetimedb::table(name = entity, public)]
pub struct Entity {
    pub position: Vector2,
}

#[derive(SpacetimeType, Debug, Clone, Copy)]
pub struct Vector2 {
    pub x: f32,
    pub y: f32,
}

#[spacetimedb::reducer]
pub fn spawn_food(ctx: &ReducerContext) -> Result<(), String> {
    let count = ctx.db.entity().count();
    if count < 600 as u64 {
        ctx.db.entity().try_insert(Entity {
            position: Vector2 { x: 0.0, y: 0.0 },
        })?;
    }
    Ok(())
}

And repro process:

echo "Publishing.."
spacetime publish -s local circle-test --delete-data --yes

echo "Updating count.."
sed -i'' 's/\<600\>/6000/' src/lib.rs

echo "Republishing.."
spacetime publish -s local circle-test

echo "Reverting count.."
sed -i'' 's/\<6000\>/600/' src/lib.rs

[cloutiertyler]

This ended up being a schema issue which is fixed now in: #1813