Description

Implement eslint/no-magic-numbers and typescript-eslint/no-magic-numbers.

Want to contribute? Lets you know you are interested! We will assign you to the issue to prevent several people to work on the same issue. Don't worry, we can unassign you later if you are no longer interested in the issue! Read our contributing guide and analyzer contributing guide.

See the related discussion for context.

The ESLint rule has many options.
I suggest implementing a single option ignoreIntegers (See the Options section) for the time being.

Here are the exceptions we should bake in:

• ignore assignment to constant-like variables, i.e. const, var, and static class properties

  const A = 0.25;
  const B = 0.25;
  class Foo {
    static C = 0.5;
  }

• Ignore common numbers
  We should always ignore 0/0n/0., and maybe 2/2n, 1/1n, and -1/-1n.

  -1; 0; 1; -1n; 0n; 1n;

  Should we ignore more integers?

• Ignore integer indexing (corresponds setting ESLints' ignoreArrayIndexes and ignoreTypeIndexes to true)

  arr[10];
  type Foo = Bar[10];
  type Baz = Parameters<Foo>[10];

• Ignore integer Enum values (corresponds setting ESLint's ignoreEnums to true)

  enum E {
    A = 3;
    B = 4;
  }

• ignore numeric types (corresponds setting ESLint's ignoreNumericLiteralTypes to true)

  type SmallPrimes = 2 | 3 | 5 | 7 | 11;
  function f(x: 100): 100 { return x }

• Ignore integer binary operations

  const x = 1 << 4;
  const x = a & 0xff;
  const x = a | 0x0f;

• Others?

Options

We could introduce an ignoreIntegers option (turned off by default).
When the option is set to true, all integers values are ignored:

1795;
1795n;