Not every class has tests, but every class on your transcript should have a final grade. Teachers in schools need tests to evaluate 30 children at a time. When homeschooling, though, we have very few students to assess at one time, and tests are not necessary in every class. To find out how to assign grades to your homeschool high school without tests, read my article How To Evaluate without Tests.
You can easily estimate grades for classes with no tests. This estimate will help you whether you are evaluating a single assignment (like a research paper or a lab report) or an entire class (like English or PE, that may not include tests.)
Quick grading estimate
Grade A or 4.0: means mastery, and the child meets high expectations, has high test scores, the child loves the subject, or the parent is not annoyed with what the child has done.
Grade B or 3.0: is good, but certainly not worth an A, or the parent is somewhat annoyed.
Grade C or 2.0: is not very good at all, the parent is both annoyed and disappointed, but kept going onto the next level in the subject.
If you believe your child is getting a C or below in a homeschool class, take action to make sure they can be successful. A low grade can mean a curriculum mismatch, or that you aren't taking their learning style into consideration in your evaluation.