What causes "Unknown display type: ${String(type satisfies never)}" in actualbudget/actual?

Log the offending action.type to find which dispatch site sends the unknown action.

Unknown display type: ${String(type satisfies never)}

Error message

Unknown display type: ${String(type satisfies never)}

What it means

templateReducer is the top-level reducer for the budget goals template editor state. Its default branch throws this when an action's discriminator is not one of the handled action types (e.g. 'set-template', 'update-template', change-type actions). The `type satisfies never` assertion means TypeScript guarantees exhaustiveness over the Action union, so a runtime hit means an action with an unrecognized `type` was dispatched — typically a typo, an action from another reducer, or a stale serialized action.

Source

Thrown at packages/desktop-client/src/components/budget/goals/reducer.ts:364

  action: Action,
): ReducerState => {
  const type = action.type;
  switch (type) {
    case 'set-type':
      return {
        ...state,
        ...changeType(state, action.payload),
      };
    case 'set-template':
      return {
        ...state,
        ...getInitialState(action.payload),
      };
    case 'update-template':
      return mapTemplateTypesForUpdate(state, action.payload);
    default:
      // Make sure we're not missing any cases
      throw new Error(`Unknown display type: ${String(type satisfies never)}`);
  }
};

View on GitHub (pinned to d4334cb6e6)

Solutions

Log the offending action.type to find which dispatch site sends the unknown action.
Fix the dispatch site to use a valid action type from the Action union in ./actions.
If a new action was added, add a case for it in templateReducer.
Type the dispatcher with React's Dispatch<Action> so TypeScript rejects unknown action types at compile time.

Example fix

// before
dispatch({ type: 'update-templates' as never });
// after
dispatch({ type: 'update-template', payload: template });

Defensive patterns

Strategy: type-guard

Validate before calling

const ACTION_TYPES = new Set(['set-template','update-template','change-type' /* ...all union members */]);
if (!ACTION_TYPES.has(action.type)) return state; // ignore unknown actions

Type guard

function isGoalsAction(a: { type: string }): a is Action {
  return GOALS_ACTION_TYPES.has(a.type);
}

Try / catch

try {
  dispatch(action);
} catch (err) {
  logger.error('Bad action for templateReducer', action, err);
}

Prevention

Type useReducer with Dispatch<Action> from ./actions so unknown action literals fail compilation.
Never use `as any`/`as never` when dispatching; let TypeScript check action shapes.
Add new action types to the Action union and reducer cases together.
In tests, iterate every member of the Action union against the reducer to prove exhaustiveness.

When it happens

Trigger: Dispatching an action to templateReducer whose `type` literal is not part of the goals/actions Action union — e.g. calling dispatch with a hand-written object `{ type: 'update-templates' }`, wiring the wrong reducer to a dispatcher, or dispatching actions from a different feature into this reducer.

Common situations: Refactoring action type strings without updating all dispatch sites; copy-pasting a reducer and dispatching foreign actions at it; custom integrations or tests dispatching malformed actions.

Related errors

AI-assisted analysis of actualbudget/actual@d4334cb6e6 (2026-08-29). Data as JSON: /api/errors/b1a4bf1588c2c731. Report an issue: GitHub.