"no-invalid-this" gives false-negative result

[vitalymak]

• ESLint Version: 4.4.1
• Node Version: 8.2.1
• npm Version: 5.3.0

What parser (default, Babel-ESLint, etc.) are you using? default

What did you do? Please include the actual source code causing the issue.

../node_modules/.bin/eslint --no-eslintrc no-invalid-this-test.js 

no-invalid-this-test.js file contents:

/*eslint no-invalid-this: "error"*/
/*eslint-env es6*/

let o = {
    name: "O name",
    f: function() {
        console.log(this.name)
    }
};

o.f = ((func, arg) => function() {
    console.log('Executing wrapper with arg ' + arg);
    func.call(this);
})(o.f, 'blah');

o.f();

What did you expect to happen?
No error.

What actually happened? Please include the actual, raw output from ESLint.

/Users/vitaly/Work/n/build/no-invalid-this-test.js
  13:15  error  Unexpected 'this'  no-invalid-this

✖ 1 problem (1 error, 0 warnings)

[not-an-aardvark]

Thanks for the report. However, this is working as intended -- the rule documentation defines what it means for a use of this to be "valid", and your code does not meet that definition.

[vitalymak]

But this doesn't give an error:

/*eslint no-invalid-this: "error"*/
/*eslint-env es6*/

let o = {
    name: "O name",
    f: function() {
        console.log(this.name)
    }
};

o.f = ((func, arg) => {return function() {
    console.log('Executing wrapper with arg ' + arg);
    func.call(this);
}})(o.f, 'blah');

o.f();

diff lines:

--- o.f = ((func, arg) => function() {
+++ o.f = ((func, arg) => {return function() {

--- })(o.f, 'blah');
+++ }})(o.f, 'blah');

[not-an-aardvark]

Hmm, it looks like there's some special logic being used for return statements to check for method assignments (relevant code). We should probably update that to check for arrow function returns as well.