Found unused expressions JS-0093
Bug risk
Minor
4 months ago
—
3 years old
Found unused expression
10491 }
10492 }),
10493 (Toggle.prototype.onPointerUp = function (event) {
10494 typedoc.hasPointerMoved ||10495 (this.setActive(!0), event.preventDefault())10496 }),
10497 (Toggle.prototype.onDocumentPointerDown = function (e) {
10498 if (this.active) {Found unused expression
10310 preventPress && e.preventDefault()
10311 }),
10312 $('body').on('keydown', function (e) {
10313 e.altKey ||10314 e.ctrlKey ||10315 e.metaKey ||10316 (!hasFocus && e.keyCode > 47 && e.keyCode < 112 && $field.focus())10317 })
10318 })((search = typedoc.search || (typedoc.search = {})))
10319})(typedoc || (typedoc = {})),Found unused expression
10258 .addClass('current')
10259 } else {
10260 const $rel = dir == 1 ? $current.next('li') : $current.prev('li')
10261 $rel.length > 0 &&10262 ($current.removeClass('current'), $rel.addClass('current'))10263 }
10264 }
10265 function gotoCurrentResult () {Found unused expression
10242 value == SearchLoadingState.Ready && updateResults())
10243 }
10244 function setHasFocus (value) {
10245 hasFocus != value &&10246 ((hasFocus = value),10247 $el.toggleClass('has-focus'),10248 value ? (setQuery(''), $field.val('')) : $field.val(query))10249 }
10250 function setQuery (value) {
10251 (query = $.trim(value)), updateResults()Found unused expression
10235 }
10236 }
10237 function setLoadingState (value) {
10238 loadingState != value &&10239 ($el.removeClass(SearchLoadingState[loadingState].toLowerCase()),10240 (loadingState = value),10241 $el.addClass(SearchLoadingState[loadingState].toLowerCase()),10242 value == SearchLoadingState.Ready && updateResults())10243 }
10244 function setHasFocus (value) {
10245 hasFocus != value &&
Description
An unused expression that does not affect the state of the program indicates a logic error.
For example, if a programmer wants to increment the value of a variable a by one, and intends to do so through this code:
let a = 0
a = a + 1
console.log(a) // output 1
But because of a typo, writes the following:
let a = 0
a + 1
console.log(a)
Here, the expression a + 1 does nothing meaningful in the program's runtime.
The expression is thus considered "unused" and should be removed.
Bad Practice
0
if(0) 0
{0}
f(0), {}
a, b()
c = a, b;
a() && function namedFunctionInExpressionContext () {f();}
(function anIncompleteIIFE () {});
injectGlobal`body{ color: red; }`
Recommended
{} // In this context, this is a block statement, not an object literal
{myLabel: someVar} // In this context, this is a block statement with a label and expression, not an object literal
function namedFunctionDeclaration () {}
(function aGenuineIIFE () {}());
f()
a = 0
new C
delete a.b
void a