Function computeAriaLabel

src/helpers/accessibility.ts:152–184

(instance: TestInstance)

}

export function computeAriaLabel(instance: TestInstance): string | undefined {
  const labelElementIds = getAriaLabelledByIds(instance);
  if (labelElementIds.length > 0) {
    const container = getContainerInstance(instance);
    const labelTexts = labelElementIds
      .map((labelElementId) => {
        const labelInstance = findAll(
          container,
          (node) => isTestInstance(node) && node.props.nativeID === labelElementId,
          { includeHiddenElements: true },
        );

        return labelInstance.length > 0 ? getTextContent(labelInstance[0]) : undefined;
      })
      .filter((labelText): labelText is string => labelText !== undefined);

    if (labelTexts.length > 0) {
      return labelTexts.join(' ').trim().replace(/\s+/g, ' ');
    }
  }

  const explicitLabel = instance.props['aria-label'] ?? instance.props.accessibilityLabel;
  if (explicitLabel) {
    return explicitLabel;
  }

  //https://github.com/facebook/react-native/blob/8dabed60f456e76a9e53273b601446f34de41fb5/packages/react-native/Libraries/Image/Image.ios.js#L173
  if (isHostImage(instance) && instance.props.alt) {
    return instance.props.alt;
  }

  return undefined;
}

function getAriaLabelledByIds(instance: TestInstance): string[] {
  const ariaLabelledBy = instance.props['aria-labelledby'];