[no-unused-vars] is not reported in a scenario.

I am using eslint@2.8.0 babel-eslint@6.0.4 node v6.0.0 npm 3.8.6

My rule is set to "no-unused-vars": 1

function test(options) {
    options = options || {};
    // Shouldn't this should give no-unused-vars error here?
}

test({});

In above scenario since options object is not used thus IMHO this should raise no-unused-vars error.

I tested this on online demo of eslint also.

[platinumazure]

Hmm… I’ve reconsidered. I think it might be sufficient to provide an option which simply says, if a variable is on LHS and RHS of an assignment, don’t assume it is used.

function myFunc(a) {
    a = a + 1;
    // But wait, I'm still not really using a beyond the assignment,
    // so the assignment was actually pretty useless.
}

Also, I’m wondering about the compound-assignment operators. Do they count as usage?

function myOtherFunc(a) {
    a += 1;  // Is this a "use" per no-unused-params?
}

If the compound-assignment doesn’t count as a use, I fail to see how unwrapped assign-after-operator (a = a + 1) should count as a use either.

[mikesherov]

👍 for @platinumazure’s suggestion, not optional. That is, until a is used for something other than self assignment, consider it unused.