rojo/.cursor/plans/live_syncback_float_precision_1be79350.plan.md

name	overview	todos	isProject
Live syncback fixes	Fix five issues: lost Workspace attributes, spurious ClockTime, Rojo_Ref_CurrentCamera leak, and float precision noise via f32 truncation.	id content status fix-attributes-encoding Add explicit Attributes/Tags encoding to encodeService.lua (mirroring encodeInstance.lua) completed id content status fix-clocktime Filter non-serializable properties server-side in build_dom_from_chunks using the Rust reflection DB completed id content status fix-currentcamera-ref Stop Rojo_Ref_CurrentCamera from leaking: filter deferred_referents after camera destruction in syncback_loop completed id content status fix-float-rounding Truncate all float values to f32 in UnresolvedValue::from_variant for rbxl parity completed	false

Live Syncback Fixes

Issue 1: Workspace Attributes/Properties Lost

Root cause: encodeService.lua iterates classDescriptor.properties but the Luau RbxDom database may not list Attributes and Tags as enumerable properties. encodeInstance.lua has explicit encodeAttributes() / encodeTags() helpers using instance:GetAttributes() / instance:GetTags() directly.

Fix: Add explicit Attributes and Tags encoding to [plugin/src/ChangeBatcher/encodeService.lua](plugin/src/ChangeBatcher/encodeService.lua) after the property loop. Add if propertyName == "Attributes" or propertyName == "Tags" then continue end to the main loop to avoid double-encoding.

Issue 2: Lighting.ClockTime Appearing

Root cause: Luau DB marks ClockTime as serializable; Rust DB marks it as DoesNotSerialize. Plugin sends it, CLI syncback filters it.

Fix: In [src/cli/serve.rs](src/cli/serve.rs) build_dom_from_chunks, filter each plugin-sent property through should_property_serialize from the Rust reflection DB before applying it to the builder.

Issue 3: Rojo_Ref_CurrentCamera Leaking (pre-existing bug)

Root cause: collect_referents captures Workspace.CurrentCamera -> Camera ref before camera is destroyed. link_referents writes Rojo_Ref_CurrentCamera without checking target still exists.

Fix: In [src/syncback/mod.rs](src/syncback/mod.rs), after camera destruction (line 222), filter deferred_referents.path_links to remove entries whose target ref no longer exists.

Issue 4: Float Precision

Root cause: Live syncback sends Float64 from Lua; rbxl stores Float32. Tiny diffs cause properties to fail default comparison.

Fix: In [src/resolution.rs](src/resolution.rs) UnresolvedValue::from_variant, truncate ALL float values to f32 precision. This is the single chokepoint for json5 writes:

• Float32(n) (line 67): already f32, n as f64 is fine (no change needed)
• Float64(n) (line 68): change to (n as f32) as f64 to truncate
• Vector2 (line 82): (vector.x as f32) as f64 etc
• Vector3 (line 85): same
• CFrame (lines 90-103): all 12 components
• Color3 (line 88): already f32, fine
• UDim/UDim2: fall through to FullyQualified -- add a round_variant helper that truncates float components to f32 before wrapping

Helper:

fn truncate_to_f32(v: f64) -> f64 {
    (v as f32) as f64
}

Deferred: Matching Parity

Matching differences between live and CLI syncback are likely downstream of the above fixes (extra properties inflating scores, missing attributes, float diffs). Revisit after these four fixes land. If matching is still off, consider reusing the previously-served tree instead of creating a fresh ServeSession::new_oneshot in run_live_syncback.