Should there be a comma before “so” in the following sentence?
Solution 1:
Your hunch is right: the online grammar checker is wrong. You don't need a comma here. It's helpful to remember so can mean and so or so that. When it means and so and joins two independent clauses, a comma is generally considered necessary. For example, Programmers can write efficient and type-safe code, [and] so good ones are in high demand. But in your sentence, so means so that -- which does not need a comma. Grammar checkers often make this error, in my experience.