useDateNow

Diagnostic Category: lint/complexity/useDateNow

JavaScript (and super languages)

Since: v1.8.0

Sources:

Same as: unicorn/prefer-date-now

Description

Use Date.now() to get the number of milliseconds since the Unix Epoch.

Date.now() is more readable than new Date().getTime() and its variants, it also avoids unnecessary instantiation of Date object.

Examples

Invalid

const foo = new Date().getTime();

code-block.js:1:13 lint/complexity/useDateNow  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ Use Date.now() instead of new Date().getTime.
  
  > 1 │ const foo = new Date().getTime();
      │             ^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Date.now() is more readable and also avoids unnecessary instantiation of Dateobject.
  
  ℹ Unsafe fix: Replace with Date.now().
  
    1   │ - const·foo·=·new·Date().getTime();
      1 │ + const·foo·=·Date.now();
    2 2 │

const foo = new Date().valueOf();

code-block.js:1:13 lint/complexity/useDateNow  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ Use Date.now() instead of new Date().valueOf.
  
  > 1 │ const foo = new Date().valueOf();
      │             ^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Date.now() is more readable and also avoids unnecessary instantiation of Dateobject.
  
  ℹ Unsafe fix: Replace with Date.now().
  
    1   │ - const·foo·=·new·Date().valueOf();
      1 │ + const·foo·=·Date.now();
    2 2 │

const foo = +new Date();

code-block.js:1:13 lint/complexity/useDateNow  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ Use Date.now() instead of new Date().
  
  > 1 │ const foo = +new Date();
      │             ^^^^^^^^^^^
    2 │ 
  
  ℹ Date.now() is more readable and also avoids unnecessary instantiation of Dateobject.
  
  ℹ Unsafe fix: Replace with Date.now().
  
    1   │ - const·foo·=·+new·Date();
      1 │ + const·foo·=·Date.now();
    2 2 │

const foo = Number(new Date());

code-block.js:1:13 lint/complexity/useDateNow  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ Use Date.now() instead of Number(new Date()).
  
  > 1 │ const foo = Number(new Date());
      │             ^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Date.now() is more readable and also avoids unnecessary instantiation of Dateobject.
  
  ℹ Unsafe fix: Replace with Date.now().
  
    1   │ - const·foo·=·Number(new·Date());
      1 │ + const·foo·=·Date.now();
    2 2 │

const foo = new Date() * 2;

code-block.js:1:13 lint/complexity/useDateNow  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ Use Date.now() instead of new Date().
  
  > 1 │ const foo = new Date() * 2;
      │             ^^^^^^^^^^
    2 │ 
  
  ℹ Date.now() is more readable and also avoids unnecessary instantiation of Dateobject.
  
  ℹ Unsafe fix: Replace with Date.now().
  
    1   │ - const·foo·=·new·Date()·*·2;
      1 │ + const·foo·=·Date.now()*·2;
    2 2 │

Valid

const foo = Date.now();

const foo = Date.now() * 2;

How to configure

{
  "linter": {
    "rules": {
      "complexity": {
        "useDateNow": "error"
      }
    }
  }
}