02-testing-intro

before - 01-intro

why test §

role of test - measure software quality to give confidence

what is testing? running program to see if it behaves as expected

• proving over infinite set impossible, have samples

testing

• dynamically runs program
• consider specific software
• run test cases
• identify diff

test quality goals §

• functional - expected output given input
• nonfunctional - output independent goals met
  • performance, scalability, security, documentation

preliminary terminology §

1. fault/ defect - flaws in static software
2. failure - observable, incorrect behaviour
3. error/ infection - incorrect internal state
4. latent defect - unobserved defect in delivered software

test def §

functional test cases have

• input i to provide program
• oracle O for expected bahavuir

so,

• O(i) == P(i) - pass
• O(i) != P(i) - fail

test oracles §

sometimes simple - unit test

sometimes tricky

• result strictly specified? (content, order, timing)
• program deterministic?

sampling §

problem: cannot check all possible inputs

so, find representative sample

test approaches §

• test until out of time
• test until out of money
• identify redundant input based on spec (blackbox)
• identify redundant input based on program structure (whitebox)
• identify poorly tested areas

after - 03-unit-testing