Map-like interface Deno.env

[SyrupThinker]

As noted in #4933

[bartlomieju]

I'm happy with this API. Leaving it to @piscisaureus for final review

[ry]

I was wondering if we could call it entries instead of getAll while still returning an object. Isn’t that an iterator still?

[bartlomieju]

I was wondering if we could call it entries instead of getAll while still returning an object. Isn’t that an iterator still?

entries() return iterator object (the one that has next() method); plain objects don't have iterator implementation

EDIT: Oooops I somehow edited @ry's comment by mistake

[ry]

getAll() sounds strange to me.

A couple of other possibilities:

• forEach method to bring it inline with Map.
• entries method which returned a Array<[string, string]> - this is an iterable object
• toObject() method which does what getAll is doing now.

none of these are particularly great...

[bartlomieju]

getAll() sounds strange to me.

A couple of other possibilities:

• forEach method to bring it inline with Map.
• entries method which returned a Array<[string, string]> - this is an iterable object
• toObject() method which does what getAll is doing now.

none of these are particularly great...

The best one would be entries() - but to turn it into object, one would need to wrap it additionally in Object.fromEntries()

const env = Object.fromEntries(Deno.env.entries());

vs 

const env = Deno.env.getAll();

Just for reference; in Rust:

let env = env::vars(); (returns interator)

let envVar = env::var("my_var");

env::set_var("my_var", "my_value");

env::remove_var("my_car");

[ry]

I agree that entries is ideal too. What if we just did toObject() for now, and add a TODO for entries()?

[SyrupThinker]

Wouldn't the entries() implementation basically be Object.entries(Deno.env.toObject())?

[bartlomieju]

After further discussion we've settled on get()/set()/toObject(). @SyrupThinker can you update the PR?

[ry]

LGTM - thanks @SyrupThinker !

[jakajancar]

What's the benefit of the Map-like interface over Deno.env simply being an object already?

console.log(Deno.env.SOMETHING);
Deno.env.SOMETHING_ELSE = "BLAH";

[ry]

@jakajancar We want to make it look less like you're updating some object - but rather calling functions which have side-effects. In particular, in Windows the env vars are not case sensitive.

[jakajancar]

Ah, the Windows situation is reason enough. That would indeed look odd if properties changed in unexpected ways.

Thanks for the explanation!