AppData.getArray() can return null, expected empty array

[andreas-andersson]

What, where

When using a page-list component and leaving it empty the return value is sometimes null, not as expexted an emtpy Node[].

From the AppData interface it should always be an array of Nodes.

export interface AppData {
  get(...key: string[]): unknown;
  getNode(key: string): Node;
  getArray(key: string): Node[];
  getNumber(key: string): number;
}

Example

config/index.html

      <input
        type="hidden"
        data-types="sv:archive"
        data-component="page-list"
        name="articlePathNodes"
        id="articlePathNodes"
        data-sortable
      />

...
let articlePathNodes = appData.getArray("articlePathNodes") as Node[];
articlePathNodes = articlePathNodes.filter((node: Node) => nodeTypeUtil.isArchive(node));
...

The resulting error is only visible on the addon preview.

EcmaError: TypeError: Cannot call method "filter" of null (<sitevision>#1890)