Slate v2 Core React Proof Ralph Plan

Supporting plan. For current queue and roadmap truth, see master-roadmap.md.

Goal

Ship the first honest proof slice for Slate v2:

• .tmp/slate-v2/packages/slate-v2
• .tmp/slate-v2/support/slate-v2-react-proof

The slice must prove the snapshot/store/replacement contract can support selector-first React 19.2+ reads without effect mirroring.

Locked Constraints

• no real DOM editing surface
• no history package
• no migration or compatibility work
• no broad bug-family payoff
• keep core data-model-first
• keep operations first-class externally
• stop if the harness still needs effect mirroring or mutable-editor reads

Execution Plan

Phase 1: Repo Grounding

Status: completed

• inspect .tmp/slate-v2 workspace/build/test constraints
• inspect whether support/slate-v2-react-proof can stay private and non-workspace
• identify the smallest package and command surface needed for the spike

Phase 2: Core Slice Definition

Status: completed

• freeze the first implementation seam:
  • createEditor
  • editor.apply
  • Editor.withTransaction
  • getSnapshot
  • subscribe
  • explicit replacement seam
• freeze the smallest transform subset needed to prove those seams

Phase 3: Implement packages/slate-v2

Status: completed

• scaffold package
• implement provisional snapshot store and transaction runner
• implement explicit replacement
• implement enough op lowering and transforms for the proof subset
• add targeted unit/integration tests

Phase 4: Implement React Proof Harness

Status: completed

• scaffold support/slate-v2-react-proof
• wire React 19.2+
• add selector-first useSyncExternalStore reads
• prove no effect mirroring
• add targeted tests

Phase 5: Verification And Review

Status: completed

• targeted package build
• targeted package typecheck
• targeted tests
• proof harness verification
• architect review
• deslop pass
• regression re-verification

Delegation Lanes

• implementation lane: local main thread unless a bounded parallel worker slice becomes obvious
• evidence/regression lane: separate agent after core and harness exist
• architect sign-off lane: separate agent after verification is green

Known Failure Conditions

• React proof requires effect mirroring
• React proof requires reading mutable in-flight editor state
• explicit replacement cannot preserve coherent snapshot semantics
• provisional package boundaries force React 19.2 assumptions into the existing workspace

Progress Log

2026-04-02

• created Ralph context snapshot
• created durable execution plan
• reading current .tmp/slate-v2 constraints and proof artifacts before code changes
• implemented packages/slate-v2 with a minimal transaction/snapshot core
• added the isolated support/slate-v2-react-proof React 19.2+ harness
• wired root Slate build, TypeScript references, and Mocha test discovery for slate-v2
• green so far:
  • fnm exec --using 22 yarn tsc --project packages/slate-v2/tsconfig.json --noEmit
  • fnm exec --using 22 yarn mocha --require ./config/babel/register.cjs ./packages/slate-v2/test/**/*.ts
  • npm run typecheck in support/slate-v2-react-proof
  • npm test in support/slate-v2-react-proof
  • fnm exec --using 22 yarn build:rollup
  • fnm exec --using 22 yarn lint:eslint
  • fnm exec --using 22 yarn lint:prettier
  • rg -n "useEffect\\(" src in support/slate-v2-react-proof returns no matches
• waiting on architect verification before the deslop pass
• architect feedback found two real contract holes, then one React proof gap, and those blockers were fixed instead of argued away
• architect approval obtained on the settled proof seam
• deslop pass removed the dead createEmptyIndex helper and unused Root type import
• post-deslop regression re-verification is green:
  • fnm exec --using 22 yarn tsc --project packages/slate-v2/tsconfig.json --noEmit
  • fnm exec --using 22 yarn mocha --require ./config/babel/register.cjs ./packages/slate-v2/test/**/*.ts
  • npm run typecheck in support/slate-v2-react-proof
  • npm test in support/slate-v2-react-proof
  • rg -n "useEffect\\(" src in support/slate-v2-react-proof returns no matches
  • fnm exec --using 22 yarn build:rollup
  • fnm exec --using 22 yarn lint:eslint
  • fnm exec --using 22 yarn lint:prettier