What is Open-Closed Principle?
Design modules so you can add behavior without editing existing code. Extend through new types, not surgery on old ones.
new handler added · core sealed
Open-Closed Principle means open for extension…
Write it in your own words in the app.
In real work
Open-closed principle: we registered a new export handler instead of editing the core pipeline.
In the illustration
A new export handler cartridge slides into the empty bay and its lamp joins the line; the core housing's wire seal stays intact and no screw on it turns.
Add the new discount type in your coding agent following the open-closed principle: a new DiscountRule type the pricing engine picks up, with no edits to the existing rules.
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