Challenge: Using Appropriate Assertions

Introduction

In this project, you’ll write a unit test that tests the behavior of a class that models a planet and its host star. To frame your state of thinking in designing the unit tests, an assessment rubric is included to indicate whether the principles taught in this section have been considered and applied.

Self-assessment rubric

I have…	Emergent	Satisfactory	Excellent
Used the correct assertions	Incorrect assertions are used.	Partially correct assertions are used.	Correct assertions used.
Understood the difference between value and reference types	There is incorrect usage of reference types.	There is partially correct usage of reference types.	There is correct usage of reference types.
Understood string, value category, enumerable/list and type assertions	There is incorrect usage.	There is partially correct usage.	There is correct usage.
Asserted floating-point numeric types correctly	No floating-point related assertions are used.	The floating-point range checking is used.	The floating-point range checking and/or percentage and/or ulp checking is used.
Tested all exceptions	Exceptions are not tested.	Exceptions are partially tested.	All the defined exceptions are tested.

Quick dive into physics before unit testing

Keep in mind the following facts before attempting the project below.

Large and small numbers with scientific notation

What if you wanted to write down a really large number, like one million? You could write out all the zeros $1000000$. You could also specify how many zeros there are after the last non-zero digits on the right (the least significant digit). In mathematical terms, this is written as $1 \times 10^6$. This is called exponential notation. $1000000$ can also be written as $1000 \times 10^3$ or $100000 \times 10^1$. It can even be written as $0.01 \times 10^8$.

What if you wanted to represent small numbers? The same principle applies, except that the exponent is negative this time. $0.000001$ is $1\times 10^{-6}$ ...