Faulty code does not throw an error

[Timyipstudio]

test("foo update", t => {
    try {
        console.log(foo);
        console.log(bar);

        var foo = 1;
        let bar = 2;
    } catch (e) {
        t.is(e.name, 'ReferenceError')
    }
});

when i run code above. it didn't throw a error

[jfmengels]

I think it's because the test code is compiled by Babel, and the compiled code is not trying to cause ReferenceError to be thrown when a variable declared with let/const is used before its declaration.

Not sure there is anything to be done about this.

(By the way, has there been a discussion to only compile only what is needed based on what is supported in the node version that runs the tests? Couldn't find one)

[sindresorhus]

Looks like a Babel bug or caveat indeed.

@Timyipstudio Could you maybe try asking about it in the Babel support channels?

Sidenote: If you want to check if something throws, use t.throws() instead.

[sindresorhus]

@jfmengels Yup: #148

[novemberborn]

I could only find babel/babel#563 on this, and there is some TDZ related code in the block-scoping plugin. So maybe this is a Babel bug or maybe Babel decided it's too hard to fix.

As far as AVA goes, we can do better by not transpiling language features that are supported by the Node.js runtime, which is #148.