Cyclomatic Complexity

Don’t write unnecessary tests anymore. Use a simple, scientific approach.

Transcript

1. foolab.ca | @foolabca Cyclomatic Complexity Bulgaria PHP, Sofia - October 8, 2016
2. Execution Paths public function getShipping() { if ($this->subtotal >= 40) { return 0; } return $this->standardShipping; } 2
3. Execution Paths public function getShipping() { if ($this->subtotal >= 40) { return 0; } return $this->standardShipping; } 3 Path 1 Path 2
4. Decision Branches 4 start product loop free shipping? end
5. Decision Branches 5 start product loop free shipping? end
6. Cyclomatic complexity = edges − nodes +
 2 * connected components
7. Decision Branches 7 start product loop free shipping? end ◦ Edges ◦ Nodes ◦ Connected components.
8. Decision Branches 8 start product loop free shipping? end ◦ Edges ◦ Nodes ◦ Connected components.
9. Decision Branches 9 start product loop free shipping? end ◦ Edges ◦ Nodes ◦ Connected components.
10. Cyclomatic complexity = 9 − 8 + 2 * 1 = 3
11. Zero Times foreach ($products as $product) { $total = $product->price * $product->quantity; } $tax = $total * ... 11
12. Multiple Times $total = 0; foreach ($products as $product) { $total = $product->price * $product->quantity; } $tax = $total * ... 12
13. Multiple Times $total = 0; foreach ($products as $product) { $total += $product->price * $product->quantity; } $tax = $total * ... 13
14. @afilina afilina.com