feuerwerk/tests/core/list-item-kind.test.ts

/**
 * What a list variable holds, chosen in the editor rather than only in a project file. Two things
 * matter: changing the item kind drags every value along (declared default, own value, overrides),
 * and a list of structs declares its item shape through the same field commands a struct does.
 */
import { describe, expect, it } from 'vitest';
import { SetOverrideCommand } from '../../src/core/commands/sceneObjectCommands';
import {
  AddStructFieldCommand,
  AddVariableCommand,
  RemoveStructFieldCommand,
  RenameStructFieldCommand,
  SetListItemsCommand,
} from '../../src/core/commands/variableCommands';
import { findAsset, objectHolders, type Project } from '../../src/core/model/Project';
import { makeBehavior, makeSpriteScene, place, roundTrip } from '../helpers';

const findObject = (project: Project, id: string) =>
  objectHolders(project)
    .flatMap((holder) => holder.objects)
    .find((o) => o.id === id);

const listDef = (project: Project, assetId: string, key: string) => {
  const asset = findAsset(project, assetId);
  const def = asset?.type === 'behavior' ? asset.variables.find((v) => v.key === key) : undefined;
  return def?.kind === 'list' ? def : undefined;
};

/** A behavior with a list variable `stops`, placed once with an override of its own. */
function withList() {
  const f = makeSpriteScene();
  const behavior = makeBehavior(f, 'B');
  f.stack.execute(new AddVariableCommand(behavior.id, 'stops', 'list'));
  const asset = findAsset(f.project, behavior.id)!;
  asset.props.stops = [1, 2];
  const object = place(f, behavior.id, { x: 0, y: 0 });
  f.stack.execute(new SetOverrideCommand(f.sceneId, object, 'stops', [3]));
  return { f, behaviorId: behavior.id, object };
}

describe('what a list variable holds', () => {
  it('starts on numbers, the one kind `+ Variable ▸ List` can pick', () => {
    const { f, behaviorId } = withList();
    expect(listDef(f.project, behaviorId, 'stops')?.items).toBe('number');
  });

  it('takes every value with it when the kind changes, and gives them back on undo', () => {
    const { f, behaviorId, object } = withList();
    f.stack.execute(new SetListItemsCommand(behaviorId, 'stops', 'text'));

    expect(listDef(f.project, behaviorId, 'stops')?.items).toBe('text');
    expect(findAsset(f.project, behaviorId)?.props.stops).toEqual(['1', '2']);
    expect(findObject(f.project, object)?.overrides.stops).toEqual(['3']);

    f.stack.undo();
    expect(listDef(f.project, behaviorId, 'stops')?.items).toBe('number');
    expect(findAsset(f.project, behaviorId)?.props.stops).toEqual([1, 2]);
    expect(findObject(f.project, object)?.overrides.stops).toEqual([3]);
  });

  /** Bare numbers have no shape, so they become the empty item rather than disappearing. */
  it('turns loose items into the empty shape when it becomes a list of structs', () => {
    const { f, behaviorId } = withList();
    f.stack.execute(new SetListItemsCommand(behaviorId, 'stops', 'struct'));
    expect(listDef(f.project, behaviorId, 'stops')?.fields).toEqual([]);
    expect(findAsset(f.project, behaviorId)?.props.stops).toEqual([{}, {}]);
  });

  it('refuses a change to the kind it already holds', () => {
    const { f, behaviorId } = withList();
    expect(() => f.stack.execute(new SetListItemsCommand(behaviorId, 'stops', 'number'))).toThrow(
      /already holds/,
    );
  });
});

describe('the item shape of a list of structs', () => {
  function withStructList() {
    const { f, behaviorId, object } = withList();
    f.stack.execute(new SetListItemsCommand(behaviorId, 'stops', 'struct'));
    f.stack.execute(new AddStructFieldCommand(behaviorId, 'stops', { key: 'x', kind: 'number' }));
    return { f, behaviorId, object };
  }

  it('grows a field in the declaration and in every item of every value at once', () => {
    const { f, behaviorId, object } = withStructList();
    expect(listDef(f.project, behaviorId, 'stops')?.fields).toEqual([{ key: 'x', kind: 'number' }]);
    expect(findAsset(f.project, behaviorId)?.props.stops).toEqual([{ x: 0 }, { x: 0 }]);
    expect(findObject(f.project, object)?.overrides.stops).toEqual([{ x: 0 }]);

    f.stack.undo();
    expect(findAsset(f.project, behaviorId)?.props.stops).toEqual([{}, {}]);
  });

  it('keeps the values of the items it does not touch when one is renamed or removed', () => {
    const { f, behaviorId } = withStructList();
    const asset = findAsset(f.project, behaviorId)!;
    asset.props.stops = [{ x: 5 }, { x: 6 }];
    f.stack.execute(new AddStructFieldCommand(behaviorId, 'stops', { key: 'y', kind: 'number' }));
    f.stack.execute(new RenameStructFieldCommand(behaviorId, 'stops', 'x', 'col'));
    expect(asset.props.stops).toEqual([
      { col: 5, y: 0 },
      { col: 6, y: 0 },
    ]);

    f.stack.execute(new RemoveStructFieldCommand(behaviorId, 'stops', 'y'));
    expect(asset.props.stops).toEqual([{ col: 5 }, { col: 6 }]);

    f.stack.undo();
    expect(asset.props.stops).toEqual([
      { col: 5, y: 0 },
      { col: 6, y: 0 },
    ]);
  });

  /** `list → struct → list → primitive` is one level deeper than anything the model stores. */
  it('refuses a list field, which a struct variable does allow', () => {
    const { f, behaviorId } = withStructList();
    const listField = { key: 'inner', kind: 'list', items: 'number' } as const;
    expect(() => f.stack.execute(new AddStructFieldCommand(behaviorId, 'stops', listField))).toThrow(
      /cannot sit in the items of a list/,
    );

    f.stack.execute(new AddVariableCommand(behaviorId, 'route', 'struct'));
    f.stack.execute(new AddStructFieldCommand(behaviorId, 'route', listField));
    expect(findAsset(f.project, behaviorId)?.props.route).toEqual({ inner: [] });
  });

  it('survives being written out and read back in', () => {
    const { f, behaviorId } = withStructList();
    findAsset(f.project, behaviorId)!.props.stops = [{ x: 5 }, { x: 6 }];
    const back = roundTrip(f.project);
    expect(listDef(back, behaviorId, 'stops')).toMatchObject({
      items: 'struct',
      fields: [{ key: 'x', kind: 'number' }],
    });
    expect(findAsset(back, behaviorId)?.props.stops).toEqual([{ x: 5 }, { x: 6 }]);
  });
});