Function findViaDirective

packages/core/src/render3/context_discovery.ts:291–309

* Locates the directive within the given LView and returns the matching index

(lView: LView, directiveInstance: {})

 * Locates the directive within the given LView and returns the matching index
 */
function findViaDirective(lView: LView, directiveInstance: {}): number {
  // if a directive is monkey patched then it will (by default)
  // have a reference to the LView of the current view. The
  // element bound to the directive being search lives somewhere
  // in the view data. We loop through the nodes and check their
  // list of directives for the instance.
  let tNode = lView[TVIEW].firstChild;
  while (tNode) {
    const directiveIndexStart = tNode.directiveStart;
    const directiveIndexEnd = tNode.directiveEnd;
    for (let i = directiveIndexStart; i < directiveIndexEnd; i++) {
      if (lView[i] === directiveInstance) {
        return tNode.index;
      }
    }
    tNode = traverseNextElement(tNode);
  }
  return -1;
}

/**
 * Returns a list of directives applied to a node at a specific index. The list includes