State Management

Ensure correct state management and prevent unnecessary "known after apply" values.

UseStateForUnknown for Computed Attributes

Always add UseStateForUnknown() plan modifier to stable computed attributes (IDs, creation timestamps). This prevents unnecessary "(known after apply)" in plans for values that don't change after creation.

Do NOT use it on attributes that change on every update (e.g., last_modified).

State Consistency Rules

• Create: Set ALL attributes in state after the API call, including computed values from the response
• Read (resource): Refresh ALL attributes from the API response. Handle not-found with resp.State.RemoveResource(ctx) to remove the resource from state gracefully
• Read (data source): Refresh ALL attributes from the API response. Handle not-found with resp.Diagnostics.AddError() — data sources MUST return an error when the item is not found (never use RemoveResource in a data source)
• Update: Set complete state from the API response, not just changed fields
• Delete: Do NOT call resp.State.Set() -- the framework removes state automatically

Anti-Patterns

• Setting partial state (only some attributes) -- causes state drift
• Missing UseStateForUnknown() on IDs -- causes unnecessary plan diffs
• Calling resp.State.Set() in Delete -- not needed, state is removed automatically
• Not handling "not found" in Read -- stale resources in state
• Using RemoveResource in a data source Read -- data sources must return an error diagnostic when the item is not found

See Resources for complete CRUD implementations. See Plan Modifiers for UseStateForUnknown details.