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  • Blocks with shared variable scopes?

Blocks with shared variable scopes?

# Mohsen Azimi (4 years ago)

I was looking at our test code and noticed we do this variable declaration gymnastic to get it to work:

describe('thing', () => {

let thing: Thing; beforeEach(() => {

thing = new Thing() }) it('does one thing', () => {

thing.oneThing() }) it('does other things', () => {

thing.otherThings() }) })

To me, the declaration of thing and binding it in the beforeEach block seemed kind of weird. In an ideal world I would declare thing in my beforeEach block and via language features communicate that scope of beforeEach's callback and describe's callback above should be the same.

Has this come up before? Has there been proposals to address this issue?

# Gus Caplan (4 years ago)

I would either tweak the framework:

describe('thing', () => { provide(() => new Thing()); it('does one thing', (thing) => { thing.oneThing(); }); it('does other things', (thing) => { thing.otherThings(); }); });

or just explicitly do const thing = new Thing() in each test.

# sup at aguz.me (4 years ago)

"It is a feature not a bug". Having to declare local variables in the scope that contains all the code that’s going to use them allows you to control what the variables are exposed to, it prevents you from writing or reading someone else’s variable, and it serves as documentation.

Agus