Function getValuesFromItem

csv/stringify.ts:177–217

* Returns an array of values from an object using the property accessors * (and optional transform function) in each column

(
  item: DataItem,
  normalizedColumns: readonly NormalizedColumn[],
)

 * (and optional transform function) in each column
 */
function getValuesFromItem(
  item: DataItem,
  normalizedColumns: readonly NormalizedColumn[],
): unknown[] {
  const values: unknown[] = [];

  if (normalizedColumns.length) {
    for (const column of normalizedColumns) {
      let value: unknown = item;

      for (const prop of column.prop) {
        if (typeof value !== "object" || value === null) {
          continue;
        }
        if (Array.isArray(value)) {
          if (typeof prop === "number") value = value[prop];
          else {
            throw new TypeError(
              'Property accessor is not of type "number"',
            );
          }
        } // I think this assertion is safe. Confirm?
        else value = (value as Record<string, unknown>)[prop];
      }

      values.push(value);
    }
  } else {
    if (Array.isArray(item)) {
      values.push(...item);
    } else if (typeof item === "object") {
      throw new TypeError(
        "No property accessor function was provided for object",
      );
    } else {
      values.push(item);
    }
  }

  return values;
}

/**
 * Converts an array of objects into a CSV string.