Function canRemoveCommonModule

packages/core/schematics/utils/parse_html.ts:128–137

(template: string)

 * determines if the CommonModule can be safely removed from imports
 */
export function canRemoveCommonModule(template: string): boolean {
  const parsed = parseTemplate(template);
  let removeCommonModule = false;
  if (parsed.tree !== undefined) {
    const visitor = new CommonCollector();
    visitAll(visitor, parsed.tree.rootNodes);
    removeCommonModule = visitor.count === 0;
  }
  return removeCommonModule;
}

/** Finds all non-control flow elements from common module. */
class CommonCollector extends RecursiveVisitor {