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Test-Driven React
book

Test-Driven React

by Trevor Burnham
June 2019
Intermediate to advanced
192 pages
4h
English
Pragmatic Bookshelf
Content preview from Test-Driven React

Getting Started with Styled-Components

As apps grow, they can contain thousands of style rules—too many for a single person to keep track of. This leads to unintended conflicts. For example, which of the styles below will apply to a disabled button with the white class?

 // StylesheetA.css
 button.white {
  background-color: white;
  color: black;
 }
 
 // StylesheetB.css
 button:disabled {
  background-color: grey;
  color: darkgrey;
 }

The answer is that it depends on the order the stylesheets are loaded in, as both selectors have the same level of specificity. This is a very fragile state of affairs for a complex app. Worse, removing style rules becomes a risky endeavor. Let’s say that your app has this style rule:

 p.alert-message {
  color: ...
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Publisher Resources

ISBN: 9781680507058Errata Page