What does your header text actually say?

Real app headers often include noise: sort arrows, counts, badges. headerTransformer runs on each header before it's stored — the cleaned name is what you use everywhere else in getRow, getCell, etc.

Name ↑	Department ↓	Salary	Status	Start Date
Ada	Engineering	90000	Active	2022-03-01
Bob	Marketing	65000	Active	2021-07-15
Carol	Engineering	95000	On Leave	2020-11-08

headerTransformer: async ({ text }) => text.replace(/[↑↓▲▼]/g, '').trim()
// Result: 'Name', 'Department', 'Salary', 'Status', 'Start Date'

Config: headerTransformer

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→ API Reference: Config Options — headerTransformer