Function isStylingMatch

packages/core/src/render3/styling/style_binding_list.ts:444–465

* Determines if two `TStylingKey`s are a match. * * When computing whether a binding contains a duplicate, we need to compare if the instruction * `TStylingKey` has a match. * * Here are examples of `TStylingKey`s which match given `tStylingKeyCursor` is: * - `color` * - `color` // Matc

(tStylingKeyCursor: TStylingKey, tStylingKey: TStylingKeyPrimitive)

 * @param tStylingKey
 */
function isStylingMatch(tStylingKeyCursor: TStylingKey, tStylingKey: TStylingKeyPrimitive) {
  ngDevMode &&
    assertNotEqual(
      Array.isArray(tStylingKey),
      true,
      "Expected that 'tStylingKey' has been unwrapped",
    );
  if (
    tStylingKeyCursor === null || // If the cursor is `null` it means that we have map at that
    // location so we must assume that we have a match.
    tStylingKey == null || // If `tStylingKey` is `null` then it is a map therefor assume that it
    // contains a match.
    (Array.isArray(tStylingKeyCursor) ? tStylingKeyCursor[1] : tStylingKeyCursor) === tStylingKey // If the keys match explicitly than we are a match.
  ) {
    return true;
  } else if (Array.isArray(tStylingKeyCursor) && typeof tStylingKey === 'string') {
    // if we did not find a match, but `tStylingKeyCursor` is `KeyValueArray` that means cursor has
    // statics and we need to check those as well.
    return keyValueArrayIndexOf(tStylingKeyCursor, tStylingKey) >= 0; // see if we are matching the key
  }
  return false;
}