ignitae Academy

Refactoring JavaScript

Four classic smells, four working-but-ugly starters, and tests that only go green when the shape of the code changes.

Syllabus

Guard clauses

Flatten the arrow: replace nested conditionals with guard clauses
Refactor: nested conditionals to guard clauses (exercise)

Extract function

Extract the duplicated expression into a named function
Refactor: extract the duplicated subtotal (exercise)

Replace loop with pipeline

Replace the loop with a pipeline of array methods
Refactor: for loop to filter and map (exercise)

Decompose a god function

Decompose a god function into single-purpose helpers
Refactor: decompose a god function (exercise)