Function callRule

packages/angular_devkit/schematics/src/rules/call.ts:65–75

(
  rule: Rule,
  input: Tree | Observable<Tree>,
  context: SchematicContext,
)

}

export function callRule(
  rule: Rule,
  input: Tree | Observable<Tree>,
  context: SchematicContext,
): Observable<Tree> {
  if (isObservable(input)) {
    return input.pipe(mergeMap((inputTree) => callRuleAsync(rule, inputTree, context)));
  } else {
    return defer(() => callRuleAsync(rule, input, context));
  }
}

async function callRuleAsync(rule: Rule, tree: Tree, context: SchematicContext): Promise<Tree> {
  let result = await rule(tree, context);