conductor/SLICE5.md

Slice 5: Validation and Error Handling

Status

Not started

Roadmap Alignment

This slice owns Validation and Error Handling in ROADMAP.md and the canonical-model/frontend-hardening portions of the older Step 25. Page onLoad execution and the schema/runtime component mismatch are already resolved and must not return as pending audit findings.

Objective

Reject invalid project definitions consistently and explain editor, persistence, and Preview failures clearly without losing user work.

Dependencies

• Canonical schema and backend validator
• Slice 1 component contracts and Slice 2 visual configuration model
• Slice 3 and 4 structured security errors for final integration

In Scope

• Validation on every persistence path
• Cross-reference and semantic validation
• Editor and Preview diagnostics
• Structured backend errors and safe recovery

Out of Scope

• AI remediation, arbitrary transforms, and enterprise audit workflows

Tasks

• Inventory validation behavior across JSON Apply, create/update, load, and Preview.
• Centralize backend schema validation and reuse it on every save path.
• Reject invalid documents without partial persistence updates.
• Add supported schema-version checks.
• Validate duplicate IDs/names and dangling action, component, variable, event, and binding references.
• Validate component-specific properties and binding target compatibility.
• Standardize backend error codes and response shapes.
• Surface errors in visual configuration screens and the JSON Editor.
• Add Preview loading, empty, upstream-error, mapping-error, and recovery states.
• Preserve unsaved edits when validation or network operations fail.
• Reconcile examples with canonical binding behavior.
• Reconcile free-form binding triggers with runtime-supported triggers.
• Unify or explicitly document path-parameter interpolation.
• Resolve, remove, document, or defer modeled-but-unexecuted fields such as Binding.transform, ComponentEvent.inputMap, and component-level bindings.
• Strengthen project.settings TypeScript typing to match the schema.
• Decide whether backend-supported project deletion requires a v0.1.0 UI control.
• Review deletion confirmations, keyboard accessibility, disabled/hidden component behavior, and Inspector/runtime agreement.
• Add malformed, semantic, version, and recovery regression tests.
• Update state and validation documentation.

Acceptance Criteria

• No create or update path persists an invalid canonical document.
• Errors identify actionable paths and messages.
• Visual Editor, JSON Editor, backend, and Preview agree on supported shapes.
• Runtime failures are visible without corrupting project or runtime state.
• Valid examples continue to round-trip.

Validation

• Frontend and backend TypeScript checks pass.
• Validator unit and route tests pass.
• Valid examples pass and invalid examples fail as expected.
• Save/load rollback and manual error scenarios pass.

Risks and Open Questions

• JSON Schema cannot express all semantic rules.
• Severity must distinguish blocking errors from warnings.
• Pre-stable 0.x documents need a compatibility policy.

Progress Log

No work recorded yet.

Handoff

• Last completed: Slice plan created.
• Next action: Build a validation matrix for every entry point and error class.
• Known blockers: Define unsupported schema-version behavior.