noThenProperty (since v1.5.0)

Diagnostic Category: lint/suspicious/noThenProperty

Sources:

Same as: unicorn/no-thenable

Disallow then property.

When combining objects with a then method (thenable objects) with await expressions or dynamic imports, caution is necessary. These syntaxes interpret the object’s then method as intended for the resolution or rejection of a promise, which can lead to unexpected behavior or errors.

Examples

Invalid

export {then};

code-block.js:1:9 lint/suspicious/noThenProperty ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Do not export then.
  
  > 1 │ export {then};
      │         ^^^^
    2 │

const foo = {
    then() {}
};

code-block.js:2:5 lint/suspicious/noThenProperty ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Do not add then to an object.
  
    1 │ const foo = {
  > 2 │     then() {}
      │     ^^^^
    3 │ };
    4 │

const foo = {
    get then() {}
};

code-block.js:2:9 lint/suspicious/noThenProperty ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Do not add then to an object.
  
    1 │ const foo = {
  > 2 │     get then() {}
      │         ^^^^
    3 │ };
    4 │

const foo = {
   get then() {}
};

code-block.js:2:8 lint/suspicious/noThenProperty ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Do not add then to an object.
  
    1 │ const foo = {
  > 2 │    get then() {}
      │        ^^^^
    3 │ };
    4 │

foo.then = function () {}

code-block.js:1:1 lint/suspicious/noThenProperty ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Do not add then to an object.
  
  > 1 │ foo.then = function () {}
      │ ^^^^^^^^
    2 │

class Foo {
    then() {}
}

code-block.js:2:5 lint/suspicious/noThenProperty ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Do not add then to a class.
  
    1 │ class Foo {
  > 2 │     then() {}
      │     ^^^^
    3 │ }
    4 │

class Foo {
    static then() {}
}

code-block.js:2:12 lint/suspicious/noThenProperty ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Do not add then to a class.
  
    1 │ class Foo {
  > 2 │     static then() {}
      │            ^^^^
    3 │ }
    4 │

Valid

export {then as success};

const foo = {
    success() {}
};

class Foo {
    success() {}
}

const foo = bar.then;

noThenProperty (since v1.5.0)

Examples

Invalid

Valid

Related links