Test Adequacy Activity
We will gain experience improving test suites using two adequacy criteria: line coverage and mutation coverage. The instructions refer to line numbers in transcriptService.ts. Do not change that file while you are following along, or else you may find that the line referenced do not match what you see.
Test Coverage
As usual, download the starter code and run npm install.
Then run the tests, using npm test. You should see that all tests pass, but lines 91 and 110 are not covered. Write tests to cover those lines. Create a file called newTests.test.ts and put your new tests there. You can run npm test to see if your tests pass.
Then run npm run stryker to see the mutation report. You should see that 12 mutants survived. Classify the surviving mutants into innocuous (didn’t introduce a bug) and non-innocuous (did introduce a bug).
In the file newTests.test.ts, write tests that will kill the non-innocuous mutants. For each mutant that you classified as innocuous, write a comment explaining why you think it is innocuous.
Grading:
- +1 point for covering each of the two uncovered lines
- +1 point for each mutant correctly classified as innocuous or non-innocuous and killed if non-innocuous (up to 12 points).
- Total grade is the sum of the two parts, up to 10 points.
Be sure to review the canvas assignment for submission and other related details (if assigned).