conductor/SLICE5.md

Slice 5: Validation and Error Handling

Status

Not started

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.
• 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.