feat: add default option

[bjohansebas]

A new option is added to determine the default behavior when Accept-Encoding is not sent by the client, defaulting to identity.

closes#83

[bjohansebas]

Hi @IamLizu, could you review this PR?

[IamLizu]

Hey @bjohansebas 👋

Sure, I will read the relevant issues and then review this PR 👍

[IamLizu]

Hi @bjohansebas 👋

I'm generally 👍 of the concept of introducing an enforcement mechanism, as discussed in #83.

However, would you mind renaming the variable defaultEnconfig to something that doesn't conflict with zlib.createGzip or zlib.createDeflate? It seems this conflict may have led to the addition of the following block:

if(opts.defaultEncoding){opts.defaultEncoding=undefined}

I suggest enforceEncoding, more on this below. Renaming the variable would help keep the code clean, and it’s important that we avoid such conflicts.

Thanks so much for your understanding and effort!

[bjohansebas]

@IamLizu Good catch

[IamLizu]

LGTM 👍

There's something I should address. As we know, content negotiation is handled by negotiator here, and it is indeed negotiator's responsibility to choose the best method.

Maybe we are interfering with negotiator's responsibilities?

cc: @expressjs/express-tc

[bjohansebas]

@UlisesGascon ping

[wesleytodd]

I dont see * referenced anywhere but here. Can you describe why this is necessary when you could drop this check and just have folks pass gzip directly for this?

[bjohansebas]

If * is not checked and changed, the deflate encoding would be applied as it’s the last one in the check (

compression/index.js

Lines 196 to 198 in 66c0cb7

	stream=method==='gzip'
	? zlib.createGzip(opts)
	: zlib.createDeflate(opts)

), and deflate is not the encoding we want to be applied, it should be gzip when it’s *.

[wesleytodd]

Sorry but I don't follow your description? To me it looks like this value for the option (coming from the calling code) could just be dropped entirely.

[bjohansebas]

I haven't found a way to eliminate this check.

[bjohansebas]

@wesleytodd Is there any change I need to make?

[wesleytodd]

It looks to me like this was merged with a pending "change requested" review. Is that the case?

[wesleytodd]

Sorry but I don't follow your description? To me it looks like this value for the option (coming from the calling code) could just be dropped entirely.

[bjohansebas]

Sorry for merging this with a change request, I now know I need to wait until the approval is there.