function diffProperties()

in Libraries/Renderer/implementations/ReactFabric-profiling.js [1440:1524]
85 lines of code
39 McCabe index (conditional complexity)

function diffProperties(updatePayload, prevProps, nextProps, validAttributes) {
  var attributeConfig, propKey;
  for (propKey in nextProps)
    if ((attributeConfig = validAttributes[propKey])) {
      var prevProp = prevProps[propKey];
      var nextProp = nextProps[propKey];
      "function" === typeof nextProp &&
        ((nextProp = !0), "function" === typeof prevProp && (prevProp = !0));
      "undefined" === typeof nextProp &&
        ((nextProp = null),
        "undefined" === typeof prevProp && (prevProp = null));
      removedKeys && (removedKeys[propKey] = !1);
      if (updatePayload && void 0 !== updatePayload[propKey])
        if ("object" !== typeof attributeConfig)
          updatePayload[propKey] = nextProp;
        else {
          if (
            "function" === typeof attributeConfig.diff ||
            "function" === typeof attributeConfig.process
          )
            (attributeConfig =
              "function" === typeof attributeConfig.process
                ? attributeConfig.process(nextProp)
                : nextProp),
              (updatePayload[propKey] = attributeConfig);
        }
      else if (prevProp !== nextProp)
        if ("object" !== typeof attributeConfig)
          defaultDiffer(prevProp, nextProp) &&
            ((updatePayload || (updatePayload = {}))[propKey] = nextProp);
        else if (
          "function" === typeof attributeConfig.diff ||
          "function" === typeof attributeConfig.process
        ) {
          if (
            void 0 === prevProp ||
            ("function" === typeof attributeConfig.diff
              ? attributeConfig.diff(prevProp, nextProp)
              : defaultDiffer(prevProp, nextProp))
          )
            (attributeConfig =
              "function" === typeof attributeConfig.process
                ? attributeConfig.process(nextProp)
                : nextProp),
              ((updatePayload || (updatePayload = {}))[
                propKey
              ] = attributeConfig);
        } else
          (removedKeys = null),
            (removedKeyCount = 0),
            (updatePayload = diffNestedProperty(
              updatePayload,
              prevProp,
              nextProp,
              attributeConfig
            )),
            0 < removedKeyCount &&
              updatePayload &&
              (restoreDeletedValuesInNestedArray(
                updatePayload,
                nextProp,
                attributeConfig
              ),
              (removedKeys = null));
    }
  for (var propKey$2 in prevProps)
    void 0 === nextProps[propKey$2] &&
      (!(attributeConfig = validAttributes[propKey$2]) ||
        (updatePayload && void 0 !== updatePayload[propKey$2]) ||
        ((prevProp = prevProps[propKey$2]),
        void 0 !== prevProp &&
          ("object" !== typeof attributeConfig ||
          "function" === typeof attributeConfig.diff ||
          "function" === typeof attributeConfig.process
            ? (((updatePayload || (updatePayload = {}))[propKey$2] = null),
              removedKeys || (removedKeys = {}),
              removedKeys[propKey$2] ||
                ((removedKeys[propKey$2] = !0), removedKeyCount++))
            : (updatePayload = clearNestedProperty(
                updatePayload,
                prevProp,
                attributeConfig
              )))));
  return updatePayload;
}