Convenient function for the test of small differences in fit as proposed by MacCallum et al. (2006).
This function is based on the R-Script by Dr. Timo Gnambs: https://timo.gnambs.at/research/test-of-small-difference-in-fit-sem
This function depends on "lavaan" and "semTools", both of which you'll probably already have loaded at this point.
The function only needs two arguments to be specified: fit1 and fit2, which are lavaan fit-objects.
groups is set to 1 by default and can be changed if your fits have more than one group.
alpha, rmseaa and rmseab also have default values. I recommend against changing these, but you can, if you wish to.
robust is also by default set to be TRUE, but will only work if the fitted lavaan objects contain the information for robust variants of chi-squared. This can be achieved by setting estimator = 'MLR' when fitting the object.
Feel free to contact me for questions or suggestions.