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noRedundantUseStrict (since v1.0.0)

Diagnostic Category: lint/suspicious/noRedundantUseStrict

Prevents from having redundant "use strict".

Examples

Section titled Examples

Invalid

Section titled Invalid
"use strict";
function foo() {
   "use strict";
}
suspicious/noRedundantUseStrict.js:3:3 lint/suspicious/noRedundantUseStrict  FIXABLE  ━━━━━━━━━━━━━━

  ✖ Redundant use strict directive.
  
    1 │ "use strict";
    2 │ function foo() {
  > 3 │  	"use strict";
      │  	^^^^^^^^^^^^^
    4 │ }
    5 │ 
  
  ℹ This outer use strict directive already enables strict mode.
  
  > 1 │ "use strict";
      │ ^^^^^^^^^^^^^
    2 │ function foo() {
    3 │  	"use strict";
  
  ℹ Safe fix: Remove the redundant use strict directive.
  
    1 1 │   "use strict";
    2 2 │   function foo() {
    3   │ - ·→ "use·strict";
    4   │ - }
      3 │ + ·→ }
    5 4 │   
  

"use strict";
"use strict";


function foo() {


}
suspicious/noRedundantUseStrict.js:2:1 lint/suspicious/noRedundantUseStrict  FIXABLE  ━━━━━━━━━━━━━━

  ✖ Redundant use strict directive.
  
    1 │ "use strict";
  > 2 │ "use strict";
      │ ^^^^^^^^^^^^^
    3 │ 
    4 │ function foo() {
  
  ℹ This outer use strict directive already enables strict mode.
  
  > 1 │ "use strict";
      │ ^^^^^^^^^^^^^
    2 │ "use strict";
    3 │ 
  
  ℹ Safe fix: Remove the redundant use strict directive.
  
    1 1 │   "use strict";
    2   │ - "use·strict";
    3 2 │   
    4 3 │   function foo() {
  

function foo() {
"use strict";
"use strict";
}
suspicious/noRedundantUseStrict.js:3:1 lint/suspicious/noRedundantUseStrict  FIXABLE  ━━━━━━━━━━━━━━

  ✖ Redundant use strict directive.
  
    1 │ function foo() {
    2 │ "use strict";
  > 3 │ "use strict";
      │ ^^^^^^^^^^^^^
    4 │ }
    5 │ 
  
  ℹ This outer use strict directive already enables strict mode.
  
    1 │ function foo() {
  > 2 │ "use strict";
      │ ^^^^^^^^^^^^^
    3 │ "use strict";
    4 │ }
  
  ℹ Safe fix: Remove the redundant use strict directive.
  
    1 1 │   function foo() {
    2 2 │   "use strict";
    3   │ - "use·strict";
    4 3 │   }
    5 4 │   
  

class C1 {
  test() {
    "use strict";
  }
}
suspicious/noRedundantUseStrict.js:3:3 lint/suspicious/noRedundantUseStrict  FIXABLE  ━━━━━━━━━━━━━━

  ✖ Redundant use strict directive.
  
    1 │ class C1 {
    2 │ 	test() {
  > 3 │ 		"use strict";
      │ 		^^^^^^^^^^^^^
    4 │ 	}
    5 │ }
  
  ℹ All parts of a class's body are already in strict mode.
  
  > 1 │ class C1 {
      │ ^^^^^^^^^^
  > 2 │ 	test() {
  > 3 │ 		"use strict";
  > 4 │ 	}
  > 5 │ }
      │ ^
    6 │ 
  
  ℹ Safe fix: Remove the redundant use strict directive.
  
    1 1 │   class C1 {
    2 2 │   	test() {
    3   │ - → → "use·strict";
    4   │ - → }
      3 │ + → → → }
    5 4 │   }
    6 5 │   
  

const C2 = class {
  test() {
    "use strict";
  }
};
suspicious/noRedundantUseStrict.js:3:3 lint/suspicious/noRedundantUseStrict  FIXABLE  ━━━━━━━━━━━━━━

  ✖ Redundant use strict directive.
  
    1 │ const C2 = class {
    2 │ 	test() {
  > 3 │ 		"use strict";
      │ 		^^^^^^^^^^^^^
    4 │ 	}
    5 │ };
  
  ℹ All parts of a class's body are already in strict mode.
  
  > 1 │ const C2 = class {
      │            ^^^^^^^
  > 2 │ 	test() {
  > 3 │ 		"use strict";
  > 4 │ 	}
  > 5 │ };
      │ ^
    6 │ 
  
  ℹ Safe fix: Remove the redundant use strict directive.
  
    1 1 │   const C2 = class {
    2 2 │   	test() {
    3   │ - → → "use·strict";
    4   │ - → }
      3 │ + → → → }
    5 4 │   };
    6 5 │

Valid

Section titled Valid
function foo() {


}
 function foo() {
    "use strict";
}
function bar() {
    "use strict";
}
Section titled Related links