What is the test for determining whether a legislative body has the power to make laws?

"The legislative power is the creative element in the government, and was exercised partly by the people in the formation of the Constitution. It is primarily [sic ] and original, antecedent and fundamental, and must be exercised before the other departments can have anything to do. Its exercise is a condition precedent, and the exercise of the executive and the judicial functions are conditions subsequent. The legislative power makes the laws, and then, after they are so made, the judiciary expounds and the executive executes them." (Nougues v. Douglass, supra, 7 Cal. at pp. 69-70, italics in original.)