HTMLスタイルガイド

Buttons

Button type

Button tags requires a type attribute according to the W3C HTML specification. 

// bad
<button></button>

// good
<button type="button"></button>

Button role

If an HTML element has an onClick handler but is not a button, it should have role="button". This is more accessible. 

// bad
<div onClick="doSomething"></div>

// good
<div role="button" onClick="doSomething"></div>

Blank target

Use rel="noopener noreferrer" whenever your links open in a new window, i.e. target="_blank". This prevents a security vulnerability documented by JitBit. 

// bad
<a href="url" target="_blank"></a>

// good
<a href="url" target="_blank" rel="noopener noreferrer"></a>

Do not use fake links. Use a button tag if a link only invokes JavaScript click event handlers, which is more semantic. 

// bad
<a class="js-do-something" href="#"></a>

// good
<button class="js-do-something" type="button"></button>